From 1fa31f2b43e7a986fd7e5df4102e673d440e7a4d Mon Sep 17 00:00:00 2001
From: epoberezkin <epoberezkin@users.noreply.github.com>
Date: Fri, 9 Oct 2026 06:54:29 +0000
Subject: [PATCH] deploy: 10166454fdc624b71acc5f76cf752905d340c212

---
 about.md                                      |   15 +
 about/index.html                              |    4 +
 ar/contact.md                                 |   66 +
 ar/contact/index.html                         |   69 +-
 ar/fdroid.md                                  |   25 +
 ar/fdroid/index.html                          |   30 +-
 ar/file.md                                    |   31 +
 ar/file/index.html                            |   16 +-
 ar/index.html                                 |   14 +-
 ar/index.md                                   |   73 +
 ar/invitation.md                              |   66 +
 ar/invitation/index.html                      |   69 +-
 ar/messaging.md                               |  253 ++
 ar/messaging/index.html                       |   44 +-
 ar/old/index.html                             |   24 +-
 ar/why.md                                     |   19 +
 ar/why/index.html                             |    8 +
 az/contact.md                                 |   66 +
 az/contact/index.html                         |   69 +-
 az/fdroid.md                                  |   25 +
 az/fdroid/index.html                          |   30 +-
 az/file.md                                    |   31 +
 az/file/index.html                            |   16 +-
 az/index.html                                 |   14 +-
 az/index.md                                   |   73 +
 az/invitation.md                              |   66 +
 az/invitation/index.html                      |   69 +-
 az/messaging.md                               |  253 ++
 az/messaging/index.html                       |   44 +-
 az/old/index.html                             |   24 +-
 az/why.md                                     |   19 +
 az/why/index.html                             |    8 +
 bg/contact.md                                 |   66 +
 bg/contact/index.html                         |   69 +-
 bg/fdroid.md                                  |   25 +
 bg/fdroid/index.html                          |   30 +-
 bg/file.md                                    |   31 +
 bg/file/index.html                            |   16 +-
 bg/index.html                                 |   14 +-
 bg/index.md                                   |   73 +
 bg/invitation.md                              |   66 +
 bg/invitation/index.html                      |   69 +-
 bg/messaging.md                               |  253 ++
 bg/messaging/index.html                       |   44 +-
 bg/old/index.html                             |   24 +-
 bg/why.md                                     |   19 +
 bg/why/index.html                             |    8 +
 blog.md                                       |  675 +++++
 blog/20201022-simplex-chat.html               |    4 +
 blog/20201022-simplex-chat.md                 |   17 +
 blog/20210512-simplex-chat-terminal-ui.html   |    4 +
 blog/20210512-simplex-chat-terminal-ui.md     |   23 +
 blog/20210914-simplex-chat-v0.4-released.html |    4 +
 blog/20210914-simplex-chat-v0.4-released.md   |   41 +
 blog/20211208-simplex-chat-v0.5-released.html |    4 +
 blog/20211208-simplex-chat-v0.5-released.md   |   31 +
 blog/20220112-simplex-chat-v1-released.html   |    4 +
 blog/20220112-simplex-chat-v1-released.md     |   53 +
 ...20220214-simplex-chat-ios-public-beta.html |    4 +
 blog/20220214-simplex-chat-ios-public-beta.md |   42 +
 blog/20220308-simplex-chat-mobile-apps.html   |    4 +
 blog/20220308-simplex-chat-mobile-apps.md     |   67 +
 ...04-simplex-chat-instant-notifications.html |    4 +
 ...0404-simplex-chat-instant-notifications.md |  123 +
 ...20220511-simplex-chat-v2-images-files.html |    4 +
 blog/20220511-simplex-chat-v2-images-files.md |   37 +
 .../20220524-simplex-chat-better-privacy.html |    4 +
 blog/20220524-simplex-chat-better-privacy.md  |   17 +
 ...ex-chat-new-privacy-security-settings.html |    4 +
 ...plex-chat-new-privacy-security-settings.md |   46 +
 ...e-export-import-protocol-improvements.html |    4 +
 ...ase-export-import-protocol-improvements.md |   97 +
 ...mplex-chat-v3.1-tor-groups-efficiency.html |    4 +
 ...simplex-chat-v3.1-tor-groups-efficiency.md |  112 +
 ...0220808-simplex-chat-v3.1-chat-groups.html |    4 +
 .../20220808-simplex-chat-v3.1-chat-groups.md |  112 +
 ...0901-simplex-chat-v3.2-incognito-mode.html |    4 +
 ...220901-simplex-chat-v3.2-incognito-mode.md |   98 +
 ...28-simplex-chat-v4-encrypted-database.html |    4 +
 ...0928-simplex-chat-v4-encrypted-database.md |  132 +
 ...-chat-v4.2-security-audit-new-website.html |    4 +
 ...ex-chat-v4.2-security-audit-new-website.md |  179 ++
 ...1206-simplex-chat-v4.3-voice-messages.html |    4 +
 ...221206-simplex-chat-v4.3-voice-messages.md |  129 +
 ...mplex-chat-v4.4-disappearing-messages.html |    4 +
 ...simplex-chat-v4.4-disappearing-messages.md |   94 +
 ...-simplex-chat-v4-5-user-chat-profiles.html |    4 +
 ...04-simplex-chat-v4-5-user-chat-profiles.md |  112 +
 ...230301-simplex-file-transfer-protocol.html |    4 +
 ...20230301-simplex-file-transfer-protocol.md |  154 +
 ...328-simplex-chat-v4-6-hidden-profiles.html |    4 +
 ...30328-simplex-chat-v4-6-hidden-profiles.md |  119 +
 ...sion-funding-v5-videos-files-passcode.html |    4 +
 ...vision-funding-v5-videos-files-passcode.md |  123 +
 ...sage-reactions-self-destruct-passcode.html |    4 +
 ...essage-reactions-self-destruct-passcode.md |  117 +
 ...x-chat-v5-2-message-delivery-receipts.html |    4 +
 ...lex-chat-v5-2-message-delivery-receipts.md |  176 ++
 ...cal-file-encryption-directory-service.html |    4 +
 ...local-file-encryption-directory-service.md |  123 +
 ...sktop-quantum-resistant-better-groups.html |    4 +
 ...desktop-quantum-resistant-better-groups.md |  149 +
 ...implex-ux-private-notes-group-history.html |    4 +
 ...-simplex-ux-private-notes-group-history.md |  110 +
 ...tance-signal-double-ratchet-algorithm.html |    4 +
 ...istance-signal-double-ratchet-algorithm.md |  252 ++
 ...stant-e2e-encryption-simple-migration.html |    4 +
 ...sistant-e2e-encryption-simple-migration.md |  149 +
 ...i-joined-simplex-chat-esraa-al-shafei.html |    4 +
 ...y-i-joined-simplex-chat-esraa-al-shafei.md |   29 +
 ...416-dangers-of-metadata-in-messengers.html |    4 +
 ...40416-dangers-of-metadata-in-messengers.md |   42 +
 ...nsparency-v5-7-better-user-experience.html |    4 +
 ...ransparency-v5-7-better-user-experience.md |  107 +
 ...mplex-redefining-privacy-hard-choices.html |    4 +
 ...simplex-redefining-privacy-hard-choices.md |   69 +
 ...ildren-safety-requires-e2e-encryption.html |    4 +
 ...children-safety-requires-e2e-encryption.md |   23 +
 ...8-private-message-routing-chat-themes.html |    4 +
 ...5.8-private-message-routing-chat-themes.md |  161 +
 ...f-privacy-enforcing-privacy-standards.html |    4 +
 ...-of-privacy-enforcing-privacy-standards.md |   41 +
 ...6-private-routing-new-user-experience.html |    4 +
 ...-v6-private-routing-new-user-experience.md |  238 ++
 ...y-review-better-calls-user-experience.html |    4 +
 ...ity-review-better-calls-user-experience.md |  182 ++
 blog/20241016-wired-attack-on-privacy.html    |    4 +
 blog/20241016-wired-attack-on-privacy.md      |   31 +
 ...cy-and-decentralization-for-all-users.html |    4 +
 ...vacy-and-decentralization-for-all-users.md |  136 +
 ...k-v6-2-servers-by-flux-business-chats.html |    4 +
 ...ork-v6-2-servers-by-flux-business-chats.md |  110 +
 ...k-law-lead-to-mass-scale-surveillance.html |    4 +
 ...eak-law-lead-to-mass-scale-surveillance.md |   43 +
 ...privacy-preserving-content-moderation.html |    4 +
 ...s-privacy-preserving-content-moderation.md |  133 +
 ...er-experience-safety-in-public-groups.html |    4 +
 ...user-experience-safety-in-public-groups.md |  178 ++
 ...ension-for-securely-connecting-people.html |    4 +
 ...xtension-for-securely-connecting-people.md |  182 ++
 ...-contacts-protect-groups-app-security.html |    4 +
 ...me-contacts-protect-groups-app-security.md |  141 +
 ...ortium-crowdfunding-freedom-of-speech.html |    4 +
 ...nsortium-crowdfunding-freedom-of-speech.md |   59 +
 blog/20260722-simplex-public-names.html       |    4 +
 blog/20260722-simplex-public-names.md         |   56 +
 blog/20260819-simplex-chat-crowdfunding.html  |    4 +
 blog/20260819-simplex-chat-crowdfunding.md    |   62 +
 ...nick-rogers-why-i-backed-simplex-chat.html |    4 +
 ...8-nick-rogers-why-i-backed-simplex-chat.md |   73 +
 blog/20260919-simplex-supporter-badges.html   |    4 +
 blog/20260919-simplex-supporter-badges.md     |   55 +
 blog/index.html                               |   16 +-
 contact.md                                    |   66 +
 contact/index.html                            |   69 +-
 credits.md                                    |  123 +
 credits/index.html                            |    4 +
 crowdfunding-news.md                          |    5 +
 crowdfunding-news/index.html                  |   28 +-
 crowdfunding.md                               |  168 ++
 crowdfunding/index.html                       |    7 +-
 cs/contact.md                                 |   65 +
 cs/contact/index.html                         |   69 +-
 cs/fdroid.md                                  |   25 +
 cs/fdroid/index.html                          |   30 +-
 cs/file.md                                    |   31 +
 cs/file/index.html                            |   39 +-
 cs/index.html                                 |   14 +-
 cs/index.md                                   |   73 +
 cs/invitation.md                              |   65 +
 cs/invitation/index.html                      |   69 +-
 cs/messaging.md                               |  253 ++
 cs/messaging/index.html                       |  184 +-
 cs/old/index.html                             |  164 +-
 cs/why.md                                     |   19 +
 cs/why/index.html                             |    8 +
 css/tailwind.css                              |    4 +
 de/contact.md                                 |   66 +
 de/contact/index.html                         |   69 +-
 de/fdroid.md                                  |   25 +
 de/fdroid/index.html                          |   30 +-
 de/file.md                                    |   31 +
 de/file/index.html                            |   51 +-
 de/index.html                                 |   14 +-
 de/index.md                                   |   73 +
 de/invitation.md                              |   66 +
 de/invitation/index.html                      |   69 +-
 de/messaging.md                               |  252 ++
 de/messaging/index.html                       |   44 +-
 de/old/index.html                             |   24 +-
 de/why.md                                     |   19 +
 de/why/index.html                             |    8 +
 directory.md                                  |    9 +
 directory/index.html                          |   24 +-
 docs.md                                       |   46 +
 docs/android.html                             |    4 +
 docs/android.md                               |   52 +
 docs/business.html                            |    4 +
 docs/business.md                              |  122 +
 docs/chat-relay.html                          |    4 +
 docs/chat-relay.md                            |  321 ++
 docs/cli.html                                 |    4 +
 docs/cli.md                                   |  240 ++
 docs/code_of_conduct.html                     |    4 +
 docs/code_of_conduct.md                       |   19 +
 docs/contributing.html                        |    4 +
 docs/contributing.md                          |  155 +
 docs/directory.html                           |    4 +
 docs/directory.md                             |   93 +
 docs/glossary.html                            |    4 +
 docs/glossary.md                              |  206 ++
 docs/guide/app-settings.html                  |    4 +
 docs/guide/app-settings.md                    |  224 ++
 docs/guide/audio-video-calls.html             |    4 +
 docs/guide/audio-video-calls.md               |   82 +
 docs/guide/channel-webpage.html               |    4 +
 docs/guide/channel-webpage.md                 |  124 +
 docs/guide/chat-profiles.html                 |    4 +
 docs/guide/chat-profiles.md                   |   96 +
 docs/guide/making-connections.html            |    4 +
 docs/guide/making-connections.md              |   81 +
 docs/guide/managing-data.html                 |    4 +
 docs/guide/managing-data.md                   |   42 +
 docs/guide/privacy-security.html              |    4 +
 docs/guide/privacy-security.md                |   57 +
 docs/guide/readme.html                        |    4 +
 docs/guide/readme.md                          |   81 +
 docs/guide/register-simplex-name.html         |    4 +
 docs/guide/register-simplex-name.md           |  119 +
 docs/guide/secret-groups.html                 |    4 +
 docs/guide/secret-groups.md                   |   66 +
 docs/guide/send-messages.html                 |    4 +
 docs/guide/send-messages.md                   |   99 +
 docs/lang/cs/android.html                     |    4 +
 docs/lang/cs/cli.html                         |    4 +
 docs/lang/cs/contributing.html                |    4 +
 docs/lang/cs/server.html                      |    4 +
 docs/lang/cs/simplex.html                     |    4 +
 docs/lang/cs/translations.html                |    4 +
 docs/lang/cs/webrtc.html                      |    4 +
 docs/lang/fr/android.html                     |    4 +
 docs/lang/fr/cli.html                         |    4 +
 docs/lang/fr/contributing.html                |    4 +
 docs/lang/fr/server.html                      |    4 +
 docs/lang/fr/simplex.html                     |    4 +
 docs/lang/fr/translations.html                |    4 +
 docs/lang/fr/webrtc.html                      |    4 +
 docs/lang/pl/android.html                     |    4 +
 docs/lang/pl/cli.html                         |    4 +
 docs/lang/pl/contributing.html                |    4 +
 docs/lang/pl/server.html                      |    4 +
 docs/lang/pl/simplex.html                     |    4 +
 docs/lang/pl/translations.html                |    4 +
 docs/lang/pl/webrtc.html                      |    4 +
 docs/protocol/badges-overview.html            |    4 +
 docs/protocol/badges-overview.md              |  307 ++
 docs/protocol/badges-rpc.html                 |    4 +
 docs/protocol/badges-rpc.md                   |   66 +
 docs/protocol/channels-overview.html          |    4 +
 docs/protocol/channels-overview.md            |  342 +++
 docs/protocol/channels-protocol.html          |    4 +
 docs/protocol/channels-protocol.md            |  273 ++
 docs/protocol/names-overview.html             |    4 +
 docs/protocol/names-overview.md               |  271 ++
 docs/protocol/simplex-chat.html               |    4 +
 docs/protocol/simplex-chat.md                 |  377 +++
 docs/server.html                              |    4 +
 docs/server.md                                | 1719 +++++++++++
 docs/simplex.html                             |    4 +
 docs/simplex.md                               |   97 +
 docs/themes.html                              |    4 +
 docs/themes.md                                |   25 +
 docs/trademark.html                           |    4 +
 docs/trademark.md                             |   33 +
 docs/translations.html                        |    4 +
 docs/translations.md                          |   99 +
 docs/webrtc.html                              |    4 +
 docs/webrtc.md                                |  152 +
 docs/why.html                                 |    5 +
 docs/why.md                                   |   21 +
 docs/xftp-server.html                         |    4 +
 docs/xftp-server.md                           |  650 ++++
 donate.md                                     |   27 +
 donate/index.html                             |    4 +
 downloads.md                                  |   44 +
 downloads/index.html                          |    4 +
 en/contact.md                                 |   66 +
 en/contact/index.html                         |   69 +-
 en/fdroid.md                                  |   25 +
 en/fdroid/index.html                          |   30 +-
 en/file.md                                    |   31 +
 en/file/index.html                            |   16 +-
 en/index.html                                 |   14 +-
 en/index.md                                   |   73 +
 en/invitation.md                              |   66 +
 en/invitation/index.html                      |   69 +-
 en/messaging.md                               |  253 ++
 en/messaging/index.html                       |   44 +-
 en/old/index.html                             |   24 +-
 en/why.md                                     |   19 +
 en/why/index.html                             |    8 +
 es/contact.md                                 |   66 +
 es/contact/index.html                         |   65 +-
 es/fdroid.md                                  |   25 +
 es/fdroid/index.html                          |   30 +-
 es/file.md                                    |   31 +
 es/file/index.html                            |   39 +-
 es/index.html                                 |   14 +-
 es/index.md                                   |   73 +
 es/invitation.md                              |   66 +
 es/invitation/index.html                      |   65 +-
 es/messaging.md                               |  254 ++
 es/messaging/index.html                       |   44 +-
 es/old/index.html                             |   24 +-
 es/why.md                                     |   19 +
 es/why/index.html                             |    8 +
 fa/contact.md                                 |   66 +
 fa/contact/index.html                         |   71 +-
 fa/fdroid.md                                  |   25 +
 fa/fdroid/index.html                          |   34 +-
 fa/file.md                                    |   31 +
 fa/file/index.html                            |   16 +-
 fa/index.html                                 |   14 +-
 fa/index.md                                   |   73 +
 fa/invitation.md                              |   66 +
 fa/invitation/index.html                      |   71 +-
 fa/messaging.md                               |  250 ++
 fa/messaging/index.html                       |   44 +-
 fa/old/index.html                             |  267 +-
 fa/why.md                                     |   19 +
 fa/why/index.html                             |    8 +
 faq.md                                        |  426 +++
 faq/index.html                                |    4 +
 fdroid.md                                     |   25 +
 fdroid/index.html                             |   30 +-
 fi/contact.md                                 |   66 +
 fi/contact/index.html                         |   71 +-
 fi/fdroid.md                                  |   25 +
 fi/fdroid/index.html                          |   34 +-
 fi/file.md                                    |   31 +
 fi/file/index.html                            |   16 +-
 fi/index.html                                 |   14 +-
 fi/index.md                                   |   73 +
 fi/invitation.md                              |   66 +
 fi/invitation/index.html                      |   71 +-
 fi/messaging.md                               |  253 ++
 fi/messaging/index.html                       |   44 +-
 fi/old/index.html                             |  275 +-
 fi/why.md                                     |   19 +
 fi/why/index.html                             |    8 +
 file.md                                       |   31 +
 file/index.html                               |   16 +-
 fr/contact.md                                 |   66 +
 fr/contact/index.html                         |   71 +-
 fr/fdroid.md                                  |   25 +
 fr/fdroid/index.html                          |   32 +-
 fr/file.md                                    |   31 +
 fr/file/index.html                            |   51 +-
 fr/index.html                                 |   14 +-
 fr/index.md                                   |   73 +
 fr/invitation.md                              |   66 +
 fr/invitation/index.html                      |   71 +-
 fr/messaging.md                               |  253 ++
 fr/messaging/index.html                       |   44 +-
 fr/old/index.html                             |   24 +-
 fr/why.md                                     |   19 +
 fr/why/index.html                             |    8 +
 he/contact.md                                 |   66 +
 he/contact/index.html                         |   73 +-
 he/fdroid.md                                  |   25 +
 he/fdroid/index.html                          |   34 +-
 he/file.md                                    |   31 +
 he/file/index.html                            |   16 +-
 he/index.html                                 |   14 +-
 he/index.md                                   |   73 +
 he/invitation.md                              |   66 +
 he/invitation/index.html                      |   73 +-
 he/messaging.md                               |  254 ++
 he/messaging/index.html                       |   44 +-
 he/old/index.html                             |  279 +-
 he/why.md                                     |   19 +
 he/why/index.html                             |    8 +
 hu/contact.md                                 |   66 +
 hu/contact/index.html                         |   69 +-
 hu/fdroid.md                                  |   25 +
 hu/fdroid/index.html                          |   30 +-
 hu/file.md                                    |   31 +
 hu/file/index.html                            |   37 +-
 hu/index.html                                 |   14 +-
 hu/index.md                                   |   73 +
 hu/invitation.md                              |   66 +
 hu/invitation/index.html                      |   69 +-
 hu/messaging.md                               |  253 ++
 hu/messaging/index.html                       |   44 +-
 hu/old/index.html                             |  245 +-
 hu/why.md                                     |   19 +
 hu/why/index.html                             |    8 +
 id/contact.md                                 |   66 +
 id/contact/index.html                         |   67 +-
 id/fdroid.md                                  |   25 +
 id/fdroid/index.html                          |   30 +-
 id/file.md                                    |   31 +
 id/file/index.html                            |   41 +-
 id/index.html                                 |   14 +-
 id/index.md                                   |   73 +
 id/invitation.md                              |   66 +
 id/invitation/index.html                      |   67 +-
 id/messaging.md                               |  253 ++
 id/messaging/index.html                       |   44 +-
 id/old/index.html                             |   24 +-
 id/why.md                                     |   19 +
 id/why/index.html                             |    8 +
 index.html                                    |   14 +-
 index.md                                      |   73 +
 invitation.md                                 |   66 +
 invitation/index.html                         |   69 +-
 it/contact.md                                 |   66 +
 it/contact/index.html                         |   69 +-
 it/fdroid.md                                  |   25 +
 it/fdroid/index.html                          |   30 +-
 it/file.md                                    |   31 +
 it/file/index.html                            |   39 +-
 it/index.html                                 |   14 +-
 it/index.md                                   |   73 +
 it/invitation.md                              |   66 +
 it/invitation/index.html                      |   69 +-
 it/messaging.md                               |  253 ++
 it/messaging/index.html                       |   44 +-
 it/old/index.html                             |   24 +-
 it/why.md                                     |   19 +
 it/why/index.html                             |    8 +
 ja/contact.md                                 |   66 +
 ja/contact/index.html                         |   67 +-
 ja/fdroid.md                                  |   25 +
 ja/fdroid/index.html                          |   32 +-
 ja/file.md                                    |   31 +
 ja/file/index.html                            |   16 +-
 ja/index.html                                 |   14 +-
 ja/index.md                                   |   73 +
 ja/invitation.md                              |   66 +
 ja/invitation/index.html                      |   67 +-
 ja/messaging.md                               |  254 ++
 ja/messaging/index.html                       |   44 +-
 ja/old/index.html                             |  267 +-
 ja/why.md                                     |   19 +
 ja/why/index.html                             |    8 +
 jobs.md                                       |   48 +
 jobs/index.html                               |    4 +
 links.md                                      | 2685 +++++++++++++++++
 links/index.html                              |   16 +-
 livestream.md                                 |    9 +
 livestream/index.html                         |    4 +
 llms-full.txt                                 | 1931 ++++++++++++
 llms.txt                                      |   92 +
 llms/agents.md                                |  158 +
 llms/answers.md                               |   74 +
 llms/facts.json                               |  369 +++
 llms/facts.md                                 |   59 +
 llms/timeline.md                              |   28 +
 messaging.md                                  |  253 ++
 messaging/index.html                          |   44 +-
 news.md                                       |    5 +
 news/index.html                               |   28 +-
 nl/contact.md                                 |   66 +
 nl/contact/index.html                         |   69 +-
 nl/fdroid.md                                  |   25 +
 nl/fdroid/index.html                          |   34 +-
 nl/file.md                                    |   31 +
 nl/file/index.html                            |   16 +-
 nl/index.html                                 |   14 +-
 nl/index.md                                   |   73 +
 nl/invitation.md                              |   66 +
 nl/invitation/index.html                      |   69 +-
 nl/messaging.md                               |  253 ++
 nl/messaging/index.html                       |   44 +-
 nl/old/index.html                             |   24 +-
 nl/why.md                                     |   19 +
 nl/why/index.html                             |    8 +
 old/index.html                                |   24 +-
 pl/contact.md                                 |   66 +
 pl/contact/index.html                         |   69 +-
 pl/fdroid.md                                  |   25 +
 pl/fdroid/index.html                          |   30 +-
 pl/file.md                                    |   31 +
 pl/file/index.html                            |   37 +-
 pl/index.html                                 |   14 +-
 pl/index.md                                   |   73 +
 pl/invitation.md                              |   66 +
 pl/invitation/index.html                      |   69 +-
 pl/messaging.md                               |  253 ++
 pl/messaging/index.html                       |   44 +-
 pl/old/index.html                             |   24 +-
 pl/why.md                                     |   19 +
 pl/why/index.html                             |    8 +
 privacy.md                                    |  255 ++
 privacy/index.html                            |    4 +
 pt_BR/contact.md                              |   66 +
 pt_BR/contact/index.html                      |   71 +-
 pt_BR/fdroid.md                               |   25 +
 pt_BR/fdroid/index.html                       |   34 +-
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 pt_BR/index.md                                |   73 +
 pt_BR/invitation.md                           |   66 +
 pt_BR/invitation/index.html                   |   71 +-
 pt_BR/messaging.md                            |  253 ++
 pt_BR/messaging/index.html                    |   44 +-
 pt_BR/old/index.html                          |   24 +-
 pt_BR/why.md                                  |   19 +
 pt_BR/why/index.html                          |    8 +
 reproduce.md                                  |  197 ++
 reproduce/index.html                          |    4 +
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 ro/contact/index.html                         |   69 +-
 ro/fdroid.md                                  |   25 +
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 ro/index.md                                   |   73 +
 ro/invitation.md                              |   66 +
 ro/invitation/index.html                      |   69 +-
 ro/messaging.md                               |  253 ++
 ro/messaging/index.html                       |   44 +-
 ro/old/index.html                             |   24 +-
 ro/why.md                                     |   19 +
 ro/why/index.html                             |    8 +
 robots.txt                                    |    4 +
 ru/contact.md                                 |   66 +
 ru/contact/index.html                         |   71 +-
 ru/fdroid.md                                  |   25 +
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 ru/index.md                                   |   73 +
 ru/invitation.md                              |   66 +
 ru/invitation/index.html                      |   71 +-
 ru/messaging.md                               |  253 ++
 ru/messaging/index.html                       |   44 +-
 ru/old/index.html                             |  279 +-
 ru/why.md                                     |   19 +
 ru/why/index.html                             |    8 +
 security.md                                   |   75 +
 security/index.html                           |    4 +
 sitemap.xml                                   |  304 ++
 tr/contact.md                                 |   66 +
 tr/contact/index.html                         |   71 +-
 tr/fdroid.md                                  |   25 +
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 tr/index.md                                   |   73 +
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 tr/invitation/index.html                      |   71 +-
 tr/messaging.md                               |  253 ++
 tr/messaging/index.html                       |   44 +-
 tr/old/index.html                             |   24 +-
 tr/why.md                                     |   19 +
 tr/why/index.html                             |    8 +
 transparency.md                               |   28 +
 transparency/index.html                       |    4 +
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 uk/contact/index.html                         |   71 +-
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 uk/index.md                                   |   73 +
 uk/invitation.md                              |   66 +
 uk/invitation/index.html                      |   71 +-
 uk/messaging.md                               |  250 ++
 uk/messaging/index.html                       |   44 +-
 uk/old/index.html                             |  269 +-
 uk/why.md                                     |   19 +
 uk/why/index.html                             |    8 +
 wefunder.md                                   |  195 ++
 why.md                                        |   19 +
 why/index.html                                |    8 +
 zh_Hans/contact.md                            |   65 +
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 zh_Hans/fdroid.md                             |   25 +
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 zh_Hans/invitation.md                         |   65 +
 zh_Hans/invitation/index.html                 |   65 +-
 zh_Hans/messaging.md                          |  251 ++
 zh_Hans/messaging/index.html                  |   44 +-
 zh_Hans/old/index.html                        |   24 +-
 zh_Hans/why.md                                |   19 +
 zh_Hans/why/index.html                        |    8 +
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 zh_Hant/invitation.md                         |   65 +
 zh_Hant/invitation/index.html                 |   67 +-
 zh_Hant/messaging.md                          |  249 ++
 zh_Hant/messaging/index.html                  |   44 +-
 zh_Hant/old/index.html                        |   24 +-
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 zh_Hant/why/index.html                        |    8 +
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diff --git a/about.md b/about.md
new file mode 100644
index 0000000000..d89404f56c
--- /dev/null
+++ b/about.md
@@ -0,0 +1,15 @@
+# About us
+
+SimpleX Chat Ltd is a company founded to develop SimpleX network and software.
+
+Our mission is to create a fully decentralized network, based on the same principles as open web, but the one that gives users full control and ownership of their identity, contacts and communities.
+
+## Contact us
+
+SimpleX: "Ask SimpleX team" contact in the app or [this address](https://simplex.chat/contact#/?v=2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion).
+
+Email: [chat@simplex.chat](mailto:chat@simplex.chat). You can use PGP to encrypt email messages using our key from [keys.openpgp.org](https://keys.openpgp.org/search?q=chat%40simplex.chat) (its fingerprint is `FB44 AF81 A45B DE32 7319 797C 8510 7E35 7D4A 17FC`) and making your key available for a secure reply.
+
+You can follow our updates on social media: [X/Twitter](https://x.com/simplexchat), [Reddit](https://www.reddit.com/r/SimpleXChat/), [Mastodon](https://mastodon.social/@simplex) and [Nostr](https://primal.net/p/npub1exv22uulqnmlluszc4yk92jhs2e5ajcs6mu3t00a6avzjcalj9csm7d828).
+
+Subscribe to our email updates via [this page](https://use.simplex.chat/email-updates) - they are sent via MailChimp as plaintext emails without any tracking.
diff --git a/about/index.html b/about/index.html
index 444c7867bd..da8016295b 100644
--- a/about/index.html
+++ b/about/index.html
@@ -52,6 +52,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8" />
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+        
+<link rel="alternate" type="text/markdown" href="/about.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
         <link href="/css/tailwind.css" rel="stylesheet" />
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css" />
diff --git a/ar/contact.md b/ar/contact.md
new file mode 100644
index 0000000000..482b6f9c4e
--- /dev/null
+++ b/ar/contact.md
@@ -0,0 +1,66 @@
+# لقد وصلتك رسالة للاتصال على SimpleX Chat
+
+## امسح رمز الـQR باستخدام تطبيق SimpleX Chat على هاتفك أو جهازك اللوحي.
+
+المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة — بل يكونوا مكتوبين داخل نص الرابط نفسه.
+
+لم تقم بتنزيل SimpleX Chat حتى الآن؟
+
+استخدم الروابط في الاسفل لتنزيل التطبيق.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+امسح رمز QR من تطبيق الجوال
+
+# لقد وصلتك رسالة للاتصال على SimpleX Chat
+
+لإجراء اتصال:
+
+قم بتثبيت تطبيق SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid)
+
+1
+
+تواصل في التطبيق
+
+افتح تطبيق Simplex
+
+2
+
+اضغط على زر "اتصل" في التطبيق
+
+3
+
+## امسح رمز QR باستخدام تطبيق SimpleX Chat
+
+لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة —
+فهي موجودة في جزء التجزئة لعنوان URL للرابط.
+
+## تثبيت SimpleX chat على الوحدة الطرفية
+
+استخدم هذا الأمر:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+انظر SimpleX Chat مستودع Github للتعليمات حول كيفية تنزيله أو تجميعه من التعليمات البرمجية المصدر.
+
+---
+
+## إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية
+
+إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية v1.0.0+, انسخ الأمر الذي في الاسفل واستخدمه في الدردشة:
+
+## انضم إلى SimpleX
+
+نحن ندعوك للانضمام إلى المُحادثة
+
+[انضم إلى مجتمع REDDIT](https://www.reddit.com/r/SimpleXChat/) [انضم إلينا على GitHub](https://github.com/simplex-chat) [تبرّع هنا لمساعدتنا](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+اشترك للحصول على آخر مستجداتنا
+
+---
+
+احصل على [تطبيق سطح المكتب](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid)
diff --git a/ar/contact/index.html b/ar/contact/index.html
index 2fd884e7a5..77f9685f1c 100644
--- a/ar/contact/index.html
+++ b/ar/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">لقد وصلتك رسالة للاتصال على SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">امسح رمز الـQR باستخدام تطبيق SimpleX Chat على هاتفك أو جهازك اللوحي.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة — بل يكونوا مكتوبين داخل نص الرابط نفسه.
+                المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة &mdash; بل يكونوا مكتوبين داخل نص الرابط نفسه.
             </p>
             <p class="text-grey-black dark:text-white text-base">لم تقم بتنزيل SimpleX Chat حتى الآن؟</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">استخدم الروابط في الاسفل لتنزيل التطبيق.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">قم بتثبيت تطبيق SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">امسح رمز QR باستخدام تطبيق SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة —<br> فهي موجودة في جزء التجزئة لعنوان URL للرابط.
+                            لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة &mdash;<br> فهي موجودة في جزء التجزئة لعنوان URL للرابط.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">تثبيت SimpleX chat على الوحدة الطرفية</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">مستودع Github</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">اشترك للحصول على آخر مستجداتنا</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="أدخل عنوان بريدك الإلكتروني">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">احصل على <a href="/downloads">تطبيق سطح المكتب</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ar/fdroid.md b/ar/fdroid.md
new file mode 100644
index 0000000000..6c82dcb4f7
--- /dev/null
+++ b/ar/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat عبر F-Droid
+
+### مستودع SimpleX Chat
+
+الإصدارات الثابتة والتجريبية التي أنشأها المطورون
+
+لإضافته إلى عميل F-Droid ،امسح رمز QR أو استخدم عنوان URL هذا:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+توقيع مفتاح البصمة (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### مستودع F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+الإصدارات الثابتة التي تم إنشاؤها بواسطة F-Droid.org
+
+تتم الإصدارات إلى هذا المستودع بعد عِدة أيام.
+
+مستودعات SimpleX Chat و F-Droid.org مبنية على مفاتيح مختلفة. للتبديل، يُرجى [صدّر](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) قاعدة بيانات الدردشة وأعد تثبيت التطبيق.
diff --git a/ar/fdroid/index.html b/ar/fdroid/index.html
index 5a59f02c90..373686b03b 100644
--- a/ar/fdroid/index.html
+++ b/ar/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat عبر F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">الإصدارات الثابتة والتجريبية التي أنشأها المطورون</p>
                         <p>لإضافته إلى عميل F-Droid ،<span class="hide-on-mobile">امسح رمز QR أو</span> استخدم عنوان URL هذا:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             توقيع مفتاح البصمة (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">مستودع F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">الإصدارات الثابتة التي تم إنشاؤها بواسطة F-Droid.org</p>
                 <p class="mb-2">تتم الإصدارات إلى هذا المستودع بعد عِدة أيام.</p>
                 <p class="mb-2">مستودعات SimpleX Chat و F-Droid.org مبنية على مفاتيح مختلفة. للتبديل، يُرجى <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">صدّر</a> قاعدة بيانات الدردشة وأعد تثبيت التطبيق.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ar/file.md b/ar/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/ar/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/ar/file/index.html b/ar/file/index.html
index aa0c1f60b8..a2ac18f0df 100644
--- a/ar/file/index.html
+++ b/ar/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ar/index.html b/ar/index.html
index 03ac90597c..6bda6f885c 100644
--- a/ar/index.html
+++ b/ar/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/ar/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/ar/fdroid" title="تطبيق SimpleX من خلال F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="إصدار SimpleX التجريبي ل iOS على TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="إصدار SimpleX التجريبي ل iOS على TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="التحقيقات الآمنية" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">الآن</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">يونيو 2027</span>
diff --git a/ar/index.md b/ar/index.md
new file mode 100644
index 0000000000..2c6d3c5b63
--- /dev/null
+++ b/ar/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# كن حراً
+
+## في شبكتك
+
+أول شبكة بدون معرّفات مستخدمين.
+أنت تملك جهات اتصالك ومجموعاتك وقنواتك.
+
+Invest in SimpleX Chat. [اقرأ أكثر.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [تطبيق SimpleX من خلال F-Droid](https://simplex.chat/ar/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[التحقيقات الآمنية](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+التحقيقات
+الآمنية
+
+[توصيات Privacy Guides للمُراسلة](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [توصيات Whonix للمُراسلة](https://www.whonix.org/wiki/Chat#Recommendation) [منشورات Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [مراجعة بواسطة Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [مقابلة بودكاست OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## لا أحد يمكنه معرفة من تتحدث إليه
+
+حتى الخوادم لا تستطيع ذلك – جميع الرسائل تبدو كضوضاء عشوائية.
+
+عشرات الملايين من الرسائل تُسلَّم بخصوصية كل يوم.
+
+[تعرّف على المزيد حول مراسلة SimpleX](https://simplex.chat/ar/messaging)
+
+## أنت تملك الشبكة
+
+كل جهة اتصال ومجموعة موجودة على جهازك، وليس في قاعدة بيانات خادم.
+
+لا يتحكم أي كيان واحد في الشبكة – يمكن لأي شخص تشغيل الخوادم.
+
+[Why we are building it](https://simplex.chat/ar/why)
+
+## يموّله مستخدموه
+
+للحفاظ على الاستقلالية، ستدفع القنوات والمجتمعات الكبيرة مقابل خوادمها.
+
+ويمكن للمستخدمين الآن الاستثمار في SimpleX Chat — التمويل الجماعي متاح!
+
+[استثمر في SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## خارطة طريق SimpleX للإنترنت المجاني
+
+2026
+
+: التوسع إلى مجتمعات كبيرة
+
+الهروب من المنصات المركزية
+
+يونيو 2027
+
+: مجتمعات وخوادم مستدامة
+
+إطلاق أرصدة المجتمع
+
+ديسمبر 2027
+
+: اجعل مجتمعاتك تنمو
+
+أدوات لتعزيز مجتمعاتك
+
+[مجموعة مستخدمي SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## انضم إلى مجتمعات SimpleX
+
+أكثر من 2 مليون شخص قاموا بتنزيل تطبيقات SimpleX.
+
+ابحث عن قنواتك ومجتمعاتك في الدليل وأنشئ قنواتك الخاصة!
+
+[اعرض دليل SimpleX](https://simplex.chat/directory)
diff --git a/ar/invitation.md b/ar/invitation.md
new file mode 100644
index 0000000000..bf12194cb1
--- /dev/null
+++ b/ar/invitation.md
@@ -0,0 +1,66 @@
+# لقد وصلك رابط يفتح مرة واحدة للاتصال على SimpleX Chat
+
+## امسح رمز الـQR باستخدام تطبيق SimpleX Chat على هاتفك أو جهازك اللوحي.
+
+المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة — بل يكونوا مكتوبين داخل نص الرابط نفسه.
+
+لم تقم بتنزيل SimpleX Chat حتى الآن؟
+
+استخدم الروابط في الاسفل لتنزيل التطبيق.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+امسح رمز QR من تطبيق الجوال
+
+# لقد وصلك رابط يفتح مرة واحدة للاتصال على SimpleX Chat
+
+لإجراء اتصال:
+
+قم بتثبيت تطبيق SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid)
+
+1
+
+تواصل في التطبيق
+
+افتح تطبيق Simplex
+
+2
+
+اضغط على زر "اتصل" في التطبيق
+
+3
+
+## امسح رمز QR باستخدام تطبيق SimpleX Chat
+
+لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة —
+فهي موجودة في جزء التجزئة لعنوان URL للرابط.
+
+## تثبيت SimpleX chat على الوحدة الطرفية
+
+استخدم هذا الأمر:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+انظر SimpleX Chat مستودع Github للتعليمات حول كيفية تنزيله أو تجميعه من التعليمات البرمجية المصدر.
+
+---
+
+## إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية
+
+إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية v1.0.0+, انسخ الأمر الذي في الاسفل واستخدمه في الدردشة:
+
+## انضم إلى SimpleX
+
+نحن ندعوك للانضمام إلى المُحادثة
+
+[انضم إلى مجتمع REDDIT](https://www.reddit.com/r/SimpleXChat/) [انضم إلينا على GitHub](https://github.com/simplex-chat) [تبرّع هنا لمساعدتنا](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+اشترك للحصول على آخر مستجداتنا
+
+---
+
+احصل على [تطبيق سطح المكتب](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ar/fdroid)
diff --git a/ar/invitation/index.html b/ar/invitation/index.html
index d7b7cdcb63..8b0fe29413 100644
--- a/ar/invitation/index.html
+++ b/ar/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">لقد وصلك رابط يفتح مرة واحدة للاتصال على SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">امسح رمز الـQR باستخدام تطبيق SimpleX Chat على هاتفك أو جهازك اللوحي.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة — بل يكونوا مكتوبين داخل نص الرابط نفسه.
+                المفتاح العام وعنوان الانتظار لا يُرسلوا عبر الشبكة عندما ترى هذه الصفحة &mdash; بل يكونوا مكتوبين داخل نص الرابط نفسه.
             </p>
             <p class="text-grey-black dark:text-white text-base">لم تقم بتنزيل SimpleX Chat حتى الآن؟</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">استخدم الروابط في الاسفل لتنزيل التطبيق.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">قم بتثبيت تطبيق SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">امسح رمز QR باستخدام تطبيق SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة —<br> فهي موجودة في جزء التجزئة لعنوان URL للرابط.
+                            لا يتم إرسال المفاتيح العامة وعنوان قائمة انتظار الرسائل في هذا الارتباط عبر الشبكة عند عرض هذه الصفحة &mdash;<br> فهي موجودة في جزء التجزئة لعنوان URL للرابط.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">تثبيت SimpleX chat على الوحدة الطرفية</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">مستودع Github</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">إذا قمت بالفعل بتثبيت SimpleX Chat للوحدة الطرفية</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">اشترك للحصول على آخر مستجداتنا</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="أدخل عنوان بريدك الإلكتروني">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">احصل على <a href="/downloads">تطبيق سطح المكتب</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ar/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ar/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ar/messaging.md b/ar/messaging.md
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--- /dev/null
+++ b/ar/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## لماذا SimpleX فريد من نوعه
+
+### لديك خصوصية كاملة
+
+يحمي SimpleX خصوصية ملف تعريفك، جهات اتصالك والبيانات الوصفية، ويخفيه عن خوادم شبكة SimpleX وأي مراقبين.
+
+على عكس أي شبكة مُراسلة آخر، لا يحتوي SimpleX على معرّفات مخصّصة للمستخدمين — **ولا حتى أرقام عشوائية**.
+
+### أنت محمي من رسائل الإزعاج وإساءة الاستخدام
+
+نظرًا لعدم وجود معرّف أو عنوان ثابت على شبكة SimpleX، لا يمكن لأي شخص الاتصال بك ما لم تشارك عنوان مستخدم لمرة واحدة أو مؤقتًا، كرمز QR أو رابط.
+
+### أنت تتحكم في بياناتك
+
+يخزن SimpleX جميع بيانات المستخدم على الأجهزة العميلة **بتنسيق قاعدة بيانات محمولة مُعمَّاة —** يمكّن نقلها إلى جهاز آخر.
+
+يتم الاحتفاظ بالرسائل المُعمَّاة بين الطرفين مؤقتًا على خوادم ترحيل SimpleX حتى يتم استلامها، ثُمَّ تُحذف نهائيًا.
+
+### أنت تمتلك شبكة SimpleX
+
+شبكة SimpleX لا مركزية بالكامل ومستقلة عن أي عملة مُعمَّاة أو أي شبكة أخرى، بخلاف الإنترنت.
+
+يمكنك **استخدام SimpleX مع خوادمك الخاصة**  أو مع الخوادم التي نوفرها — ولا يزال الاتصال ممكن بأي مستخدم.
+
+# الخصوصية الكاملة لهويتك وملفك الشخصي وجهات الاتصال والبيانات الوصفية
+
+على عكس شبكات المُراسلة الأخرى، **لا يحتوي SimpleX على معرّفات مخصصة للمستخدمين**. لا يعتمد على أرقام الهواتف أو العناوين المستندة إلى النطاقات (مثل البريد الإلكتروني أو XMPP)، أسماء المستخدمين، المفاتيح العامة أو حتى الأرقام العشوائية لتحديد مستخدميها — مُشغلي خادم SimpleX لا يعرفون عدد الأشخاص الذين يستخدمون خوادمهم.
+
+لتسليم الرسائل، يستخدم [العناوين المزدوجة المجهولة](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) لقوائم انتظار الرسائل أحادية الاتجاه، منفصلة عن الرسائل المُستلمة والمُرسلة، عادةً عبر خوادم مختلفة.
+
+يحمي هذا التصميم خصوصية الأشخاص الذين تتواصل معهم، ويخفيها عن خوادم شبكة SimpleX ومن أي مراقبين. لإخفاء عنوان IP الخاص بك من الخوادم، يمكنك  **الاتصال بخوادم SimpleX عبر تور**.
+
+# أفضل حماية من رسائل الإزعاج وإساءة الاستخدام
+
+نظرًا لعدم وجود معرّف لديك على شبكة SimpleX، لا يمكن لأي شخص الاتصال بك ما لم تشارك عنوان مستخدم لمرة واحدة أو مؤقتًا، كرمز QR أو رابط.
+
+حتى مع عنوان المستخدم الاختياري، بينما يمكن استخدامه لإرسال طلبات جهات اتصال مزعجة، يمكنك تغييره أو حذفه بالكامل دون فقد أي من اتصالاتك.
+
+# الملكية والتحكم وأمن بياناتك
+
+يخزن SimpleX Chat جميع بيانات المستخدم على أجهزة العميل فقط باستخدام  **تنسيق قاعدة بيانات محمولة مُعمَّاة**  يمكّن تصديرها ونقلها إلى أي جهاز مدعوم.
+
+يتم الاحتفاظ بالرسائل المُعمَّاة بين الطرفين مؤقتًا على خوادم ترحيل SimpleX حتى يتم استلامها، ثُمَّ تُحذف نهائيًا.
+
+على عكس خوادم الشبكات الاتحادية (البريد الإلكتروني أو XMPP أو Matrix)، لا تقوم خوادم SimpleX بتخزين حسابات المستخدمين، فهي تقوم فقط بترحيل الرسائل، مما يحمي خصوصية كلا الطرفين.
+
+لا توجد معرفّات أو نص مُعَمَّى مشترك بين حركة مرور بيانات الخادم المُرسلة والمُستلمة — إذا كان أي شخص يراقب ذلك، فلن يتمكّن بسهولة من تحديد من يتواصل مع من، حتى لو اختُرق TLS.
+
+# لامركزية بالكامل — يمتلك المستخدمون شبكة SimpleX
+
+يمكنك  **استخدام SimpleX مع خوادمك**  والاستمرار في التواصل مع الأشخاص الذين يستخدمون الخوادم المُهيأة مسبقًا في التطبيقات.
+
+تستخدم شبكة [بروتوكول مفتوح](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) وتوفر[SDK لإنشاء روبوتات دردشة](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript)، مما يسمح بتنفيذ الخدمات التي يمكن للمستخدمين التفاعل معها عبر تطبيقات SimpleX Chat — التي تتطلع حقًا لمعرفة خدمات SimpleX التي ستبنيها.
+
+إذا كنت تفكر في التطوير شبكة SimpleX، على سبيل المثال، بوت الدردشة لمستخدمي تطبيق SimpleX، أو دمج مكتبة SimpleX Chat في تطبيقات الأجهزة المحمولة، من فضلك [تواصل معي](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) لأي نصيحة والدعم.
+
+## الميزات
+
+تعمية الرسائل بين الطرفين مع دعم ماركداون والتعديل
+
+تعمية
+الصور والفيديوهات والملفات بين الطرفين
+
+المجموعات اللامركزية مُعمَّاة — المستخدمون فقط يعرفون بوجودها
+
+تعمية الرسائل الصوتية بين الطرفين
+
+رسائل ذاتية الاختفاء
+
+تعمية المكالمات الصوتية والفيديو
+بين الطرفين
+
+تخزين بيانات التطبيق مُعمَّاة ومحمولة — نقل ملف التعريف إلى جهاز آخر
+
+وضع التخفي —
+فريد من نوعه لـ SimpleX Chat
+
+## ما الذي يجعل SimpleX  خصوصيًّا
+
+### معرّفات زوجية مجهولة مؤقتة
+
+يستخدم SimpleX معرّفات مزدوجة مؤقتة مجهولة الهوية للعناوين وبيانات الاعتماد لكل جهة اتصال مستخدم أو عضو مجموعة.
+
+يسمح بتسليم الرسائل بدون معرّفات ملف تعريف المستخدم، مما يوفر خصوصية للبيانات الوصفية أفضل من البدائل.
+
+### تبديل خارج النطاق
+
+العديد من شبكات التواصل عرضة لهجمات الوسيط (MITM) من قِبل الخوادم أو موفري الشبكات.
+
+لمنع ذلك، تقوم تطبيقات SimpleX بتمرير مفاتيح لمرة واحدة خارج النطاق، عندما تُشارك عنوان كرابط أو رمز QR.
+
+### طبقتان من التعمية بين الطرفين
+
+بروتوكول Double-ratchet —
+رسائل OTR مع السرية المستمرة واستعادة الاختراق.
+
+NaCL cryptobox في كل قائمة انتظار لمنع ارتباط حركة مرور البيانات بين قوائم انتظار الرسائل في حالة اختراق TLS.
+
+### التحقق من سلامة الرسالة
+
+لضمان سلامة الرسائل يتم ترقيمها بالتسلسل وتضمين تجزئة الرسالة السابقة.
+
+إذا أُضيفت أي رسالة أو أُزيلت أو تغيّرت، فسيتم تنبيه المُستلم.
+
+### طبقة إضافية من تعمية الخادم
+
+طبقة إضافية من تعمية الخادم للتسليم إلى المُستلم، لمنع الارتباط بين حركة مرور بيانات الخادم المُستلمة والمُرسلة في حالة اختراق TLS.
+
+### خلط الرسائل لتقليل من الارتباط
+
+تعمل خوادم SimpleX كعقد مختلطة بزمن انتقال منخفض — الرسائل الواردة والصادرة لها ترتيب مختلف.
+
+### تأمين نقل TLS المصدق عليه
+
+يتم استخدام TLS 1.2 / 1.3 مع خوارزميات قوية فقط لاتصالات الخادم والعميل.
+
+تعمل بصمة الخادم وربط القناة على منع هجمات الوسيط (MITM) وإعادة التشغيل.
+
+استئناف الاتصال معطل لمنع هجمات الجلسة.
+
+### وصول اختياري عبر تور
+
+لحماية عنوان IP الخاص بك، يمكنك الوصول إلى الخوادم عبر تور أو بعض شبكات تراكب النقل الأخرى.
+
+لاستخدام SimpleX عبر تور، يُرجى تثبيت [تطبيق Orbot](https://guardianproject.info/apps/org.torproject.android/) وتمكّين وكيل SOCKS5 (أو VPN [على iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### قوائم انتظار أحادية الاتجاه
+
+كل رسالة انتظار تمرر الرسائل في اتجاه واحد، بعناوين إرسال واستلام مختلفة.
+
+إنه يقلل من نواقل الهجوم، مقارنة بوسطاء الرسائل التقليديين، والبيانات الوصفية المتاحة.
+
+### طبقات متعددة من حشوة المحتوى
+
+يستخدم SimpleX حشوة المحتوى لكل طبقة تعمية لإحباط هجمات حجم الرسالة.
+
+يجعل الرسائل ذات الأحجام المختلفة تبدو متشابهة للخوادم ومراقبي الشبكة.
+
+## شبكة SimpleX
+
+يوفر SimpleX Chat أفضل خصوصية من خلال الجمع بين مزايا P2P والشبكات الاتحادية.
+
+### على عكس شبكات P2P
+
+يتم إرسال جميع الرسائل عبر الخوادم، مما يوفر خصوصية أفضل للبيانات الوصفية وتسليمًا موثوقًا للرسائل غير المتزامنة، مع تجنب الكثير .
+
+# مقارنة مع بروتوكولات المُراسلة P2P
+
+بروتوكولات المُراسلة والتطبيقات [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) بها مشاكل مختلفة تجعلها أقل موثوقية من SimpleX وأكثر تعقيدًا في التحليل و عرضة لعدة أنواع من الهجمات.
+
+1. تعتمد شبكات P2P على بعض المتغيرات من [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) لتوجيه الرسائل. يجب أن توازن تصميمات DHT بين ضمان التسليم وزمن الوصول. تتمتع SimpleX بضمان تسليم أفضل وزمن انتقال أقل من P2P، لأنه يمكّن تمرير الرسالة بشكل متكرر عبر عدة خوادم بالتوازي، باستخدام الخوادم التي اختارها المُستلم. في شبكات P2P، يتم تمرير الرسالة عبر عُقد  *O (log N)*  بالتسلسل، باستخدام العُقد التي تختارها الخوارزمية.
+2. لا يحتوي تصميم SimpleX، عكس معظم شبكات P2P، على معرّفات مستخدم عالمية من أي نوع، حتى مؤقتة، ويستخدم فقط المعرّفات المزدوجة المؤقتة، مما يوفر إخفاء هوية أفضل وحماية للبيانات الوصفية.
+3. P2P لا يحل مشكلة [هجوم الوسيط (MITM)](https://en.wikipedia.org/wiki/Man-in-the-middle_attack)، ومعظم التطبيقات الحالية لا تستخدم خارج النطاق رسائل للتبادل الأولي للمفاتيح. يستخدم SimpleX رسائل خارج النطاق أو، في بعض الحالات، اتصالات آمنة وموثوق بها موجودة مسبقًا لتبادل المفاتيح الأولي.
+4. يمكن لبعض مزودي خدمة الإنترنت حظر تطبيقات P2P (مثل [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX حيادي النقل - يمكنه العمل عبر بروتوكولات الويب القياسية، على سبيل المثال WebSockets.
+5. قد تكون جميع شبكات P2P المعروفة عرضة [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack)، لأن كل عقدة قابلة للاكتشاف، وتعمل الشبكة ككل. تتطلب الإجراءات المعروفة لتخفيفها إما مكونًا مركزيًا أو [إثبات عمل مكلف](https://en.wikipedia.org/wiki/Proof_of_work). لا تحتوي شبكة SimpleX على إمكانية اكتشاف الخادم، فهي مجزأة وتعمل كشبكات فرعية متعددة ومعزولة، مما يجعل الهجمات على مستوى الشبكة مستحيلة.
+6. قد تكون شبكات P2P عرضة [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent)، عندما يتمكّن العملاء من إعادة بث حركة مرور البيانات وتضخيمها، مما يؤدي إلى رفض الخدمة على مستوى الشبكة. يقوم عملاء SimpleX فقط بترحيل حركة مرور البيانات من اتصال معروف ولا يمكن للمهاجم استخدامها لتضخيم حركة مرور البيانات في الشبكة بالكامل.
+
+---
+
+### على عكس الشبكات الاتحادية
+
+لا تقوم خوادم الترحيل SimpleX بتخزين ملفات تعريف المستخدمين وجهات الاتصال والرسائل التي تم تسليمها، ولا تتصل ببعضها البعض، ولا يوجد دليل خوادم.
+
+---
+
+### شبكة SimpleX
+
+توفر الخوادم  قوائم انتظار أحادية الاتجاه لتوصيل المستخدمين، لكن ليس لديهم رؤية للرسم البياني لاتصال الشبكة — إلا للمستخدمين فقط.
+
+## شرح SimpleX
+
+1. تجربة المستخدم
+
+2. كيف يعمل
+
+3. ما الذي تراة الخوادم
+
+1. تجربة المستخدم
+
+يمكنك إنشاء جهات اتصال ومجموعات وإجراء مُحادثات ثنائية الاتجاه، كما هو الحال في أي برنامج مُراسلة آخر.
+
+كيف يمكن أن تعمل مع قوائم انتظار أحادية الاتجاه وبدون معرّفات ملف تعريف المستخدم؟
+
+2. كيف يعمل
+
+لكل اتصال، تستخدم قائمتي انتظار منفصلتين للمُراسلة لإرسال واستلام الرسائل عبر خوادم مختلفة.
+
+تمرّر الخوادم الرسائل في اتجاه واحد فقط، دون الحصول على الصورة الكاملة لمُحادثات المستخدم أو اتصالاته.
+
+3. ما الذي تراة الخوادم
+
+تحتوي الخوادم على بيانات اعتماد مجهولة منفصلة لكل قائمة انتظار، ولا تعرف المستخدمين الذين ينتمون إليهم.
+
+يمكن للمستخدمين زيادة تحسين خصوصية البيانات الوصفية باستخدام تور للوصول إلى الخوادم، ومنع الارتباط بواسطة عنوان IP.
+
+## مقارنة مع البروتوكولات الأخرى
+
+|  |  | Signal، منصات كبيرة | XMPP ،Matrix | بروتوكولات P2P |
+| --- | --- | --- | --- | --- |
+| يتطلب هوية عالمية | لا - خصوصي | نعم [1] | نعم [2] | نعم [3] |
+| احتمالية هجوم الوسيط | لا - آمن [4] | نعم [5] | نعم | نعم |
+| الاعتمادية على DNS | لا - مرن | نعم | نعم | لا |
+| شبكة أحادية أو مركزية | لا - لامركزي | نعم | لا - اتِحاديّ [6] | نعم [7] |
+| مكون مركزي أو هجوم الشبكة الواسع | لا - مرن | نعم | نعم [2] | نعم [8] |
+
+---
+
+1. عادة ما يكون مكوناً من رقم الهاتف، أو اسم المستخدم في بعض الأحيان
+2. العناوين تعتمد على الـDNS
+3. المفتاح العام أو معرّف آخر فريد وعام
+4. مُرحلات SimpleX لا يمكنها أن تتنازل عن تعمية بين الطرفين. تحقق من رمز الأمان للتخفيف من الهجوم على القناة خارج النطاق
+5. إذا خوادم المشغّل مُخترقة. تحقق من رمز الأمان في Signal وبعض التطبيقات الأخرى للتخفيف منه
+6. لا يحمي خصوصية البيانات الوصفية للمستخدمين
+7. على الرغم من أن الـP2P موزعة، إلا أنها ليست اتِحاديَّة — يعملون كشبكة واحدة
+8. شبكات P2P إما لديها سلطة مركزية أو أن الشبكة كلها يمكن عرضة للخطر — [اقرأ هنا](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## مقارنة أمان التعمية بين الطرفين في برامج المُراسلة المختلفة
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| حشو الرسالة | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| الإنكار (عدم القدرة على إثبات التورط) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| السرية المستمرة | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| الأمن بعد الاختراق | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| تبادل مفتاح ثنائي العوامل | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| التعمية الهجينة ما بعد الكمومي | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. يقوم Briar بحشو الرسائل إلى حجم مقرب لأعلى إلى 1024 بايت، بينما Signal يحشوها إلى 160 بايت
+2. لا يشمل الإنكار اتصال العميل بالخادم.
+3. يبدو أن استخدام التوقيعات المُعمّاة يضر بالإنكار (عدم القدرة على التنصل)، ولكن هذا يحتاج إلى توضيح.
+4. تطبيقات الأجهزة المتعددة تعرض أمن Double Ratchet بعد الاختراق للخطر — [اقرأ هنا](https://eprint.iacr.org/2021/626.pdf).
+5. تبادل المفاتيح الثنائي اختياري عبر التحقق من رمز الأمان.
+6. اتفاقية مفتاح ما بعد الكم "متفرقة" — فهي تحمي بعض خطوات ratchet فقط.
diff --git a/ar/messaging/index.html b/ar/messaging/index.html
index 99c00a725a..e8ad6e771e 100644
--- a/ar/messaging/index.html
+++ b/ar/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">لديك خصوصية كاملة</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت محمي <br> من رسائل الإزعاج وإساءة الاستخدام</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت تتحكم في بياناتك</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت تمتلك شبكة SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">يسمح بتسليم الرسائل بدون معرّفات ملف تعريف المستخدم، مما يوفر خصوصية للبيانات الوصفية أفضل من البدائل.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">لمنع ذلك، تقوم تطبيقات SimpleX بتمرير مفاتيح لمرة واحدة خارج النطاق، عندما تُشارك عنوان كرابط أو رمز QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox في كل قائمة انتظار لمنع ارتباط حركة مرور البيانات بين قوائم انتظار الرسائل في حالة اختراق TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">إذا أُضيفت أي رسالة أو أُزيلت أو تغيّرت، فسيتم تنبيه المُستلم.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">طبقة إضافية من تعمية الخادم للتسليم إلى المُستلم، لمنع الارتباط بين حركة مرور بيانات الخادم المُستلمة والمُرسلة في حالة اختراق TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">تعمل خوادم SimpleX كعقد مختلطة بزمن انتقال منخفض — الرسائل الواردة والصادرة لها ترتيب مختلف.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">استئناف الاتصال معطل لمنع هجمات الجلسة.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">لاستخدام SimpleX عبر تور، يُرجى تثبيت <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank"> تطبيق Orbot </a> وتمكّين وكيل SOCKS5 (أو VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">على iOS </a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">إنه يقلل من نواقل الهجوم، مقارنة بوسطاء الرسائل التقليديين، والبيانات الوصفية المتاحة.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">يجعل الرسائل ذات الأحجام المختلفة تبدو متشابهة للخوادم ومراقبي الشبكة.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">انقر للإغلاق</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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diff --git a/ar/old/index.html b/ar/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">لديك خصوصية كاملة</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت محمي <br> من رسائل الإزعاج وإساءة الاستخدام</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت تتحكم في بياناتك</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">أنت تمتلك شبكة SimpleX</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ar/why.md b/ar/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/ar/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/ar/why/index.html b/ar/why/index.html
index dd482aca5a..5221a173a1 100644
--- a/ar/why/index.html
+++ b/ar/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ar/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/az/contact.md b/az/contact.md
new file mode 100644
index 0000000000..c5255b5ed0
--- /dev/null
+++ b/az/contact.md
@@ -0,0 +1,66 @@
+# You received an address to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received an address to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid)
diff --git a/az/contact/index.html b/az/contact/index.html
index 7b29051cf2..8aee3d0fd5 100644
--- a/az/contact/index.html
+++ b/az/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received an address to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
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@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/az/fdroid.md b/az/fdroid.md
new file mode 100644
index 0000000000..296adf884e
--- /dev/null
+++ b/az/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stable and beta versions built by the developers
+
+To add it to your F-Droid client, scan the QR code or use this URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stable versions built by F-Droid.org
+
+The releases to this repo are done several days later.
+
+SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please [export](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) the chat database and re-install the app.
diff --git a/az/fdroid/index.html b/az/fdroid/index.html
index e315032179..9335edb91f 100644
--- a/az/fdroid/index.html
+++ b/az/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -693,15 +698,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
                         <p>To add it to your F-Droid client, <span class="hide-on-mobile">scan the QR code or</span> use this URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,7 +718,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stable versions built by F-Droid.org</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
                 <p class="mb-2">SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">export</a> the chat database and re-install the app.</p>
@@ -720,17 +726,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/az/file.md b/az/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/az/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/az/file/index.html b/az/file/index.html
index c3165d2f22..a1c0aff77a 100644
--- a/az/file/index.html
+++ b/az/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/az/index.html b/az/index.html
index c8ea4f300b..d63e37c8dd 100644
--- a/az/index.html
+++ b/az/index.html
@@ -60,6 +60,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/az/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/az/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/az/index.md b/az/index.md
new file mode 100644
index 0000000000..a585ef9b21
--- /dev/null
+++ b/az/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Learn more.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/az/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/az/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/az/why)
+
+## Funded by Its Users
+
+To stay independent, large channels and communities will pay for their servers.
+
+And the users can now invest in SimpleX Chat — the equity crowdfunding is live!
+
+[Get a stake in SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/az/invitation.md b/az/invitation.md
new file mode 100644
index 0000000000..0043a96617
--- /dev/null
+++ b/az/invitation.md
@@ -0,0 +1,66 @@
+# You received a 1-time link to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received a 1-time link to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/az/fdroid)
diff --git a/az/invitation/index.html b/az/invitation/index.html
index 786f6a03b5..6d97d58dbf 100644
--- a/az/invitation/index.html
+++ b/az/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received a 1-time link to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
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@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/az/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/az/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/az/messaging.md b/az/messaging.md
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--- /dev/null
+++ b/az/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Why SimpleX is unique
+
+### You have complete privacy
+
+SimpleX protects the privacy of your profile, contacts and metadata, hiding it from SimpleX network servers and any observers.
+
+Unlike any other existing messaging network, SimpleX has no identifiers assigned to the users — **not even random numbers**.
+
+### You are protected from spam and abuse
+
+Because you have no identifier or fixed address on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+### You control your data
+
+SimpleX stores all user data on client devices in a **portable encrypted database format** — it can be transferred to another device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+### You own SimpleX network
+
+The SimpleX network is fully decentralised and independent of any crypto-currency or any other network, other than the Internet.
+
+You can **use SimpleX with your own servers** or with the servers provided by us — and still connect to any user.
+
+# Full privacy of your identity, profile, contacts and metadata
+
+Unlike other messaging networks, SimpleX has **no identifiers assigned to the users**. It does not rely on phone numbers, domain-based addresses (like email or XMPP), usernames, public keys or even random numbers to identify its users — SimpleX server operators don't know how many people use their servers.
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# The best protection from spam and abuse
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# Ownership, control and security of your data
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+There are no identifiers or ciphertext in common between sent and received server traffic — if anybody is observing it, they cannot easily determine who communicates with whom, even if TLS is compromised.
+
+# Fully decentralised — users own the SimpleX network
+
+You can **use SimpleX with your own servers** and still communicate with people who use the servers preconfigured in the apps.
+
+SimpleX network uses an [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) and provides [SDK to create chat bots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), allowing implementation of services that users can interact with via SimpleX Chat apps — we're really looking forward to seeing what SimpleX services you will build.
+
+If you are considering developing for the SimpleX network, for example, the chat bot for SimpleX app users, or the integration of the SimpleX Chat library into your mobile apps, please [get in touch](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) for any advice and support.
+
+## Features
+
+E2E-encrypted messages with markdown and editing
+
+E2E-encrypted
+images, videos and files
+
+E2E-encrypted decentralized groups — only users know they exist
+
+E2E-encrypted voice messages
+
+Disappearing messages
+
+E2E-encrypted
+audio and video calls
+
+Portable encrypted app storage — move profile to another device
+
+Incognito mode —
+unique to SimpleX Chat
+
+## What makes SimpleX private
+
+### Temporary anonymous pairwise identifiers
+
+SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member.
+
+It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.
+
+### Out-of-band key exchange
+
+Many communication networks are vulnerable to MITM attacks by servers or network providers.
+
+To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.
+
+### 2-layers of end-to-end encryption
+
+Double-ratchet protocol —
+OTR messaging with perfect forward secrecy and break-in recovery.
+
+NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.
+
+### Message integrity verification
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### Additional layer of server encryption
+
+Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.
+
+### Message mixing to reduce correlation
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### Secure authenticated TLS transport
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+Connection resumption is disabled to prevent session attacks.
+
+### Optional access via Tor
+
+To protect your IP address you can access the servers via Tor or some other transport overlay network.
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Unidirectional message queues
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+It reduces the attack vectors, compared with traditional message brokers, and available meta-data.
+
+### Multiple layers of content padding
+
+SimpleX uses content padding for each encryption layer to frustrate message size attacks.
+
+It makes messages of different sizes look the same to the servers and network observers.
+
+## SimpleX Network
+
+SimpleX Chat provides the best privacy by combining the advantages of P2P and federated networks.
+
+### Unlike P2P networks
+
+All messages are sent via the servers, both providing better metadata privacy and reliable asynchronous message delivery, while avoiding many .
+
+# Comparison with P2P messaging protocols
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messaging protocols and apps have various problems that make them less reliable than SimpleX, more complex to analyse, and vulnerable to several types of attack.
+
+1. P2P networks rely on some variant of [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) to route messages. DHT designs have to balance delivery guarantee and latency. SimpleX has both better delivery guarantee and lower latency than P2P, because the message can be redundantly passed via several servers in parallel, using the servers chosen by the recipient. In P2P networks the message is passed through *O(log N)* nodes sequentially, using nodes chosen by the algorithm.
+2. SimpleX design, unlike most P2P networks, has no global user identifiers of any kind, even temporary, and only uses temporary pairwise identifiers, providing better anonymity and metadata protection.
+3. P2P does not solve [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problem, and most existing implementations do not use out-of-band messages for the initial key exchange. SimpleX uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### Unlike federated networks
+
+SimpleX relay servers do NOT store user profiles, contacts and delivered messages, do NOT connect to each other, and there is NO servers directory.
+
+---
+
+### SimpleX network
+
+servers provide unidirectional queues to connect the users, but they have no visibility of the network connection graph — only the users do.
+
+## SimpleX explained
+
+1. What users experience
+
+2. How does it work
+
+3. What servers see
+
+1. What users experience
+
+You can create contacts and groups, and have two-way conversations, as in any other messenger.
+
+How can it work with unidirectional queues and without user profile identifiers?
+
+2. How does it work
+
+For each connection you use two separate messaging queues to send and receive messages via different servers.
+
+Servers only pass messages one way, without having the full picture of user's conversations or connections.
+
+3. What servers see
+
+The servers have separate anonymous credentials for each queue, and do not know which users they belong to.
+
+Users can further improve metadata privacy by using Tor to access servers, preventing correlation by IP address.
+
+## Comparison with other protocols
+
+|  |  | Signal, big platforms | XMPP, Matrix | P2P protocols |
+| --- | --- | --- | --- | --- |
+| Requires global identity | No - private | Yes [1] | Yes [2] | Yes [3] |
+| Possibility of MITM | No - secure [4] | Yes [5] | Yes | Yes |
+| Dependence on DNS | No - resilient | Yes | Yes | No |
+| Single or centralized network | No - decentralized | Yes | No - federated [6] | Yes [7] |
+| Central component or other network-wide attack | No - resilient | Yes | Yes [2] | Yes [8] |
+
+---
+
+1. Usually based on a phone number, in some cases on usernames
+2. DNS-based addresses
+3. Public key or some other globally unique ID
+4. SimpleX relays cannot compromise e2e encryption. Verify security code to mitigate attack on out-of-band channel
+5. If operator's servers are compromised. Verify security code in Signal and some other apps to mitigate it
+6. Does not protect users' metadata privacy
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. P2P networks either have a central authority or the whole network can be compromised — [see here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [see here](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/az/messaging/index.html b/az/messaging/index.html
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
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@@ -1236,7 +1240,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connection resumption is disabled to prevent session attacks.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                 </div>
                 
@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1342,7 +1346,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It reduces the attack vectors, compared with traditional message brokers, and available meta-data.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It makes messages of different sizes look the same to the servers and network observers.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
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         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
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 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/az/why.md b/az/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/az/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/az/why/index.html b/az/why/index.html
index 730884e6e1..3dff54e35e 100644
--- a/az/why/index.html
+++ b/az/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/az/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/bg/contact.md b/bg/contact.md
new file mode 100644
index 0000000000..2906b46181
--- /dev/null
+++ b/bg/contact.md
@@ -0,0 +1,66 @@
+# You received an address to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received an address to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid)
diff --git a/bg/contact/index.html b/bg/contact/index.html
index 65f903441b..0379b27282 100644
--- a/bg/contact/index.html
+++ b/bg/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received an address to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/bg/fdroid.md b/bg/fdroid.md
new file mode 100644
index 0000000000..296adf884e
--- /dev/null
+++ b/bg/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stable and beta versions built by the developers
+
+To add it to your F-Droid client, scan the QR code or use this URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stable versions built by F-Droid.org
+
+The releases to this repo are done several days later.
+
+SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please [export](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) the chat database and re-install the app.
diff --git a/bg/fdroid/index.html b/bg/fdroid/index.html
index 93923d63c3..375f54d683 100644
--- a/bg/fdroid/index.html
+++ b/bg/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -693,15 +698,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
                         <p>To add it to your F-Droid client, <span class="hide-on-mobile">scan the QR code or</span> use this URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,7 +718,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stable versions built by F-Droid.org</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
                 <p class="mb-2">SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">export</a> the chat database and re-install the app.</p>
@@ -720,17 +726,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/bg/file.md b/bg/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/bg/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/bg/file/index.html b/bg/file/index.html
index 869f66bf4b..19f7f1cb78 100644
--- a/bg/file/index.html
+++ b/bg/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/bg/index.html b/bg/index.html
index 43cab58313..574e4a1eb0 100644
--- a/bg/index.html
+++ b/bg/index.html
@@ -60,6 +60,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/bg/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/bg/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/bg/index.md b/bg/index.md
new file mode 100644
index 0000000000..f65c619c9c
--- /dev/null
+++ b/bg/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Learn more.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/bg/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/bg/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/bg/why)
+
+## Финансира се от потребителите си
+
+За да запазят независимостта си, големите канали и общности ще плащат за сървърите си.
+
+А сега потребителите могат да инвестират в SimpleX Chat — краудфандингът е активен!
+
+[Инвестирайте в SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/bg/invitation.md b/bg/invitation.md
new file mode 100644
index 0000000000..6b8206b4ea
--- /dev/null
+++ b/bg/invitation.md
@@ -0,0 +1,66 @@
+# You received a 1-time link to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received a 1-time link to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/bg/fdroid)
diff --git a/bg/invitation/index.html b/bg/invitation/index.html
index 626d0c7981..8938ef9ea8 100644
--- a/bg/invitation/index.html
+++ b/bg/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received a 1-time link to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/bg/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/bg/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/bg/messaging.md b/bg/messaging.md
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--- /dev/null
+++ b/bg/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Why SimpleX is unique
+
+### You have complete privacy
+
+SimpleX protects the privacy of your profile, contacts and metadata, hiding it from SimpleX network servers and any observers.
+
+Unlike any other existing messaging network, SimpleX has no identifiers assigned to the users — **not even random numbers**.
+
+### You are protected from spam and abuse
+
+Because you have no identifier or fixed address on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+### You control your data
+
+SimpleX stores all user data on client devices in a **portable encrypted database format** — it can be transferred to another device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+### You own SimpleX network
+
+The SimpleX network is fully decentralised and independent of any crypto-currency or any other network, other than the Internet.
+
+You can **use SimpleX with your own servers** or with the servers provided by us — and still connect to any user.
+
+# Full privacy of your identity, profile, contacts and metadata
+
+Unlike other messaging networks, SimpleX has **no identifiers assigned to the users**. It does not rely on phone numbers, domain-based addresses (like email or XMPP), usernames, public keys or even random numbers to identify its users — SimpleX server operators don't know how many people use their servers.
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# The best protection from spam and abuse
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# Ownership, control and security of your data
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+There are no identifiers or ciphertext in common between sent and received server traffic — if anybody is observing it, they cannot easily determine who communicates with whom, even if TLS is compromised.
+
+# Fully decentralised — users own the SimpleX network
+
+You can **use SimpleX with your own servers** and still communicate with people who use the servers preconfigured in the apps.
+
+SimpleX network uses an [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) and provides [SDK to create chat bots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), allowing implementation of services that users can interact with via SimpleX Chat apps — we're really looking forward to seeing what SimpleX services you will build.
+
+If you are considering developing for the SimpleX network, for example, the chat bot for SimpleX app users, or the integration of the SimpleX Chat library into your mobile apps, please [get in touch](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) for any advice and support.
+
+## Характеристика
+
+E2E-криптирани съобщения с markdown форматиране и редактиране
+
+E2E-криптирани
+изображения, видеоклипове и файлове
+
+E2E-криптирани децентрализирани групи — известни само на потребителите
+
+E2E-криптирани гласови съобщения
+
+Изчезващи съобщения
+
+E2E-криптиран
+аудио и видео разговори
+
+Преносима криптирана база данни mdash; Можете да преместите профила на друго устройство
+
+Режим инкогнито —
+уникален за SimpleX чат
+
+## What makes SimpleX private
+
+### Временни анонимни двойки идентификатори
+
+SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member.
+
+It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.
+
+### Външен носител за обмен на ключове
+
+Many communication networks are vulnerable to MITM attacks by servers or network providers.
+
+За да го предотврати SimpleX, приложенията препращат еднократни ключове през външен носител, когато се споделя адрес като линк или QR код.
+
+### 2 слоя на криптиране от край до край
+
+Double-ratchet protocol —
+OTR messaging with perfect forward secrecy and break-in recovery.
+
+NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.
+
+### Проверка на целостта на съобщението
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### Допълнителен слой на криптиране на сървъра
+
+Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.
+
+### Смесване на съобщения за намаляване на корелацията
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### Сигурен идентифициран TLS транспорт
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+Connection resumption is disabled to prevent session attacks.
+
+### Възможен достъп чрез TOR
+
+To protect your IP address you can access the servers via Tor or some other transport overlay network.
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Еднопосочни опашки за съобщенията
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+It reduces the attack vectors, compared with traditional message brokers, and available meta-data.
+
+### Множество слоеве допълнение на съдържание
+
+SimpleX uses content padding for each encryption layer to frustrate message size attacks.
+
+It makes messages of different sizes look the same to the servers and network observers.
+
+## SimpleX Network
+
+SimpleX Chat provides the best privacy by combining the advantages of P2P and federated networks.
+
+### Unlike P2P networks
+
+All messages are sent via the servers, both providing better metadata privacy and reliable asynchronous message delivery, while avoiding many .
+
+# Сравнение на P2P протоколи за съобщения
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messaging protocols and apps have various problems that make them less reliable than SimpleX, more complex to analyse, and vulnerable to several types of attack.
+
+1. P2P networks rely on some variant of [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) to route messages. DHT designs have to balance delivery guarantee and latency. SimpleX has both better delivery guarantee and lower latency than P2P, because the message can be redundantly passed via several servers in parallel, using the servers chosen by the recipient. In P2P networks the message is passed through *O(log N)* nodes sequentially, using nodes chosen by the algorithm.
+2. SimpleX design, unlike most P2P networks, has no global user identifiers of any kind, even temporary, and only uses temporary pairwise identifiers, providing better anonymity and metadata protection.
+3. P2P не решава проблема с [MITM атаките](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) и повечето съществуващи имплементации не използват съобщения по външен носител за първоначалния обмен на ключове. Simplex използва съобщения по външен носител или в някои случаи съществуващите сигурни и надеждни връзки за първоначалния обмен на ключове.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### Unlike federated networks
+
+SimpleX relay servers do NOT store user profiles, contacts and delivered messages, do NOT connect to each other, and there is NO servers directory.
+
+---
+
+### SimpleX network
+
+servers provide unidirectional queues to connect the users, but they have no visibility of the network connection graph — only the users do.
+
+## Обяснението на SimpleX
+
+1. Какъв опит като потребител
+
+2. Как работи
+
+3. Какво виждат сървърите
+
+1. Какъв опит като потребител
+
+Можете да създавате контакти и групи и да провеждате двупосочни разговори, както във всеки друго чат приложение.
+
+Как може да работи с еднопосочни опашки и без идентификатори на потребителски профили?
+
+2. Как работи
+
+За всяка връзка използвате две отделни опашки за съобщения, за да изпращате и получавате съобщения през различни сървъри.
+
+Сървърите предават съобщения само еднопосочно, без да имат пълната картина от разговорите или връзките на потребителя.
+
+3. Какво виждат сървърите
+
+Сървърите имат отделни анонимни идентификационни данни за всяка опашка и нямат информация на кои потребители принадлежат.
+
+Потребителите могат допълнително да подобрят поверителността на метаданните, като използват Tor за достъп до сървъри, предотвратявайки корелация по IP адрес.
+
+## Comparison with other protocols
+
+|  |  | Signal, big platforms | XMPP, Matrix | P2P protocols |
+| --- | --- | --- | --- | --- |
+| Requires global identity | No - private | Да [1] | Да [2] | Да [3] |
+| Possibility of MITM | No - secure [4] | Да [5] | Да | Да |
+| Dependence on DNS | No - resilient | Да | Да | Не |
+| Single or centralized network | No - decentralized | Да | No - federated [6] | Да [7] |
+| Central component or other network-wide attack | No - resilient | Да | Да [2] | Да [8] |
+
+---
+
+1. Usually based on a phone number, in some cases on usernames
+2. DNS-based addresses
+3. Public key or some other globally unique ID
+4. SimpleX релетата не могат да компрометират E2E криптирането. Проверете кода за сигурност, за да предотвратите атаката по външен носител
+5. If operator's servers are compromised. Verify security code in Signal and some other apps to mitigate it
+6. Does not protect users' metadata privacy
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. P2P networks either have a central authority or the whole network can be compromised — [see here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [see here](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/bg/messaging/index.html b/bg/messaging/index.html
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@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">За да го предотврати SimpleX, приложенията препращат еднократни ключове през външен носител, когато се споделя адрес като линк или QR код.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                 </div>
                 
@@ -1270,7 +1274,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connection resumption is disabled to prevent session attacks.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It reduces the attack vectors, compared with traditional message brokers, and available meta-data.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It makes messages of different sizes look the same to the servers and network observers.</p>
                             
                         </div>
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 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
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-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/bg/why.md b/bg/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/bg/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/bg/why/index.html b/bg/why/index.html
index 7043c3be64..c58ae18218 100644
--- a/bg/why/index.html
+++ b/bg/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/bg/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/blog.md b/blog.md
new file mode 100644
index 0000000000..6c2ca15553
--- /dev/null
+++ b/blog.md
@@ -0,0 +1,675 @@
+# Latest news
+
+[Open SimpleX Network News channel](https://simplex.chat/news)
+
+## [SimpleX Supporter Badges — Send Larger Files That Stay Available Longer, Without Being Identified](https://simplex.chat/blog/20260919-simplex-supporter-badges.html)
+
+19 Sep 2026
+
+Supporter badges are available in v7.1 beta: a badge on your profile, larger files and longer file storage — and the purchase cannot be linked to your profile.
+
+Investors in our equity crowdfunding receive badges as perks.
+
+If you invest $500 or more by November 22, you will also receive a public SimpleX name for 5 years. [Learn more and invest on Wefunder](https://wefunder.com/simplex.chat?utm_source=blog).
+
+[Read More](https://simplex.chat/blog/20260919-simplex-supporter-badges.html)
+
+## [Nick Rogers: Why I Backed SimpleX Chat in 2022, and Why I Doubled Down](https://simplex.chat/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html)
+
+08 Sep 2026
+
+Blog post by Nick Rogers, early investor and advisor of SimpleX Chat, founder of Fieldwork, former CPO & CTO of Stream.
+
+[Read More](https://simplex.chat/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html)
+
+## [Equity Crowdfunding Launched — You Can Get a Stake in SimpleX Chat](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.html)
+
+20 Aug 2026
+
+SimpleX is the first and the only messaging network without user identifiers of any kind. Our equity crowdfunding round is now launched on Wefunder, so network users, and anybody else, can get a stake in SimpleX Chat.
+
+Learn more and invest [on Wefunder](https://wefunder.com/simplex.chat?utm_source=blog).
+
+[Read More](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.html)
+
+## [SimpleX Public Names — a Name Nobody Can Take From You](https://simplex.chat/blog/20260722-simplex-public-names.html)
+
+22 Jul 2026
+
+You can now give your channel or business a test SimpleX name — from v7-beta.
+
+[Read More](https://simplex.chat/blog/20260722-simplex-public-names.html)
+
+## [SimpleX Channels, SimpleX Network Consortium and Community Crowdfunding — to Preserve Freedom of Speech](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html)
+
+30 Apr 2026
+
+Freedom of speech needs infrastructure that protects it by design — protocols, governance and funding.
+
+**v6.5 release** brings SimpleX Channels: a new model for online publishing built for participation privacy.
+
+[Read More](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html)
+
+## [SimpleX Chat v6.4.1: welcome your contacts, review members to protect groups, and more.](https://simplex.chat/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html)
+
+29 Jul 2025
+
+**v6.4.1 is released:**
+
+- welcome your contacts: set your profile bio and welcome message.
+- protect your communities from spam and abuse: review new members ("knocking").
+- set default time to delete messages for new contacts.
+- improved app integrity: Linux app builds are now reproducible.
+
+Also, we added 3 new interface languages to Android and desktop apps thanks to our users: Indonesian, Romanian and Vietnamese.
+
+[Read More](https://simplex.chat/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html)
+
+## [SimpleX network: new experience of connecting with people — available in SimpleX Chat v6.4-beta.4](https://simplex.chat/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html)
+
+03 Jul 2025
+
+Now you can start talking to your contacts much faster, as soon as you scan the link. This technical post covers the technology that enabled this new user experience — short links and associated data of messaging queues.
+
+[Read More](https://simplex.chat/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html)
+
+## [SimpleX Chat v6.3: new user experience and safety in public groups](https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html)
+
+08 Mar 2025
+
+**v6.3 is released:**
+
+- Preventing spam and abuse in public groups.
+- Group improvements: mention other members and improved performance.
+- Better chat navigation: organize chats into lists and jump to found and forwarded messages.
+- Privacy and security improvements: chat retention period and private media file names.
+
+Also, we added Catalan interface language, thanks to our users and Weblate.
+
+The last but not the least - server builds are now reproducible!
+
+[Read More](https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html)
+
+## [SimpleX network: large groups and privacy-preserving content moderation](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.html)
+
+14 Jan 2025
+
+This post explains how server operators can moderate end-to-end encrypted conversations without compromising user privacy or end-to-end encryption.
+
+[Read More](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.html)
+
+## [Oppose digital IDs – they break the law and lead to mass scale surveillance](https://simplex.chat/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.html)
+
+18 Dec 2024
+
+Starting next year, the UK government plans to introduce digital ID cards for the young people to prove their age when visiting pubs.
+
+[Read More](https://simplex.chat/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.html)
+
+## [SimpleX network: preset servers operated by Flux, business chats and more with v6.2 of the apps](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html)
+
+10 Dec 2024
+
+**v6.2 is released:**
+
+- SimpleX Chat and Flux made an agreement to include Flux-operated servers into the app to improve metadata privacy in SimpleX network.
+- Business chats for better privacy and support of your customers.
+- Better user experience: open on the first unread, jump to quoted messages, see who reacted.
+- Improving notifications in iOS app.
+
+[Read More](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html)
+
+## [Servers operated by Flux - true privacy and decentralization for all users](https://simplex.chat/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html)
+
+25 Nov 2024
+
+- **Welcome, Flux** — the new servers in **v6.2-beta.1!**
+- What's the problem?
+- Using two operators improves connection privacy.
+- SimpleX decentralization compared with Matrix, Session and Tor.
+- What's next for SimpleX decentralization?
+
+[Read More](https://simplex.chat/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html)
+
+## [Wired’s Attack on Privacy](https://simplex.chat/blog/20241016-wired-attack-on-privacy.html)
+
+16 Oct 2024
+
+The Wired article by David Gilbert focusing on neo-Nazis moving to SimpleX Chat following the Telegram's changes in privacy policy is biased and misleading. By cherry-picking information from the report by the Institute for Strategic Dialogue (ISD), Wired fails to mention that SimpleX network design prioritizes privacy in order to protect human rights defenders, journalists, and everyday users who value their privacy.
+
+[Read More](https://simplex.chat/blog/20241016-wired-attack-on-privacy.html)
+
+## [SimpleX network: cryptographic design review by Trail of Bits, v6.1 released with better calls and user experience.](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+14 Oct 2024
+
+**New security audit!**
+
+Trail of Bits reviewed the cryptographic design of protocols used in SimpleX network and apps.
+
+**v6.1 is released:**
+
+- Better calls: switch audio and video during the call.
+- Better iOS notifications: improved delivery, reduced traffic usage.
+- Better user experience: switch chat profiles, customizable message shapes, forward up to 20 messages.
+
+[Read More](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+## [SimpleX network: the investment from Jack Dorsey and Asymmetric, v6.0 released with the new user experience and private message routing.](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.html)
+
+14 Aug 2024
+
+**SimpleX Chat vision and funding 2.0:** past, present, future.
+
+Announcing the investment from Jack Dorsey and Asymmetric.
+
+**v6.0 is released:**
+
+- Private message routing - enabled by default
+- New chat experience: - connect to your friends faster. - new reachable interface. - and much more!
+- Improved networking and battery usage
+
+[Read More](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.html)
+
+## [The Future of Privacy: Enforcing Privacy Standards](https://simplex.chat/blog/20240704-future-of-privacy-enforcing-privacy-standards.html)
+
+04 Jul 2024
+
+It's time we shift the focus: privacy should be a non-negotiable duty of technology providers, not just a right users must fight to protect, and not something that users can be asked to consent away as a condition of access to a service.
+
+[Read More](https://simplex.chat/blog/20240704-future-of-privacy-enforcing-privacy-standards.html)
+
+## [SimpleX network: private message routing, v5.8 released with IP address protection and chat themes](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.html)
+
+04 Jun 2024
+
+**v5.8 is released:**
+
+- private message routing.
+- server transparency.
+- protect IP address when downloading files & media.
+- chat themes* for better conversation privacy.
+- group improvements - reduced traffic and additional preferences.
+- improved networking, message and file delivery.
+
+Also, we added Persian interface language*, thanks to our users and Weblate.
+
+* Android and desktop apps only.
+
+[Read More](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.html)
+
+## [Protecting Children's Safety Requires End-to-End Encryption](https://simplex.chat/blog/20240601-protecting-children-safety-requires-e2e-encryption.html)
+
+01 Jun 2024
+
+As lawmakers grapple with the serious issue of child exploitation online, some proposed solutions would fuel the very problem they aim to solve.
+
+[Read More](https://simplex.chat/blog/20240601-protecting-children-safety-requires-e2e-encryption.html)
+
+## [SimpleX: Redefining Privacy by Making Hard Choices](https://simplex.chat/blog/20240516-simplex-redefining-privacy-hard-choices.html)
+
+16 May 2024
+
+When it comes to open source privacy tools, the status quo often dictates the limitations of existing protocols and structures. However, these norms need to be challenged to radically shift how we approach genuinely private communication. This requires doing some uncomfortable things, like making hard choices as it relates to funding, alternative decentralization models, doubling down on privacy over convenience, and more.
+
+In this post we explain a bit more about why SimpleX operates and makes decisions the way it does:
+
+- No user accounts.
+- Privacy over convenience.
+- Network decentralization.
+- Funding and profitability.
+- Company jurisdiction.
+
+[Read More](https://simplex.chat/blog/20240516-simplex-redefining-privacy-hard-choices.html)
+
+## [SimpleX network: legally binding transparency, v5.7 released with better calls and messages](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.html)
+
+26 Apr 2024
+
+**Legally binding transparency**
+
+- We published Transparency Reports, Security Policy, and Frequently Asked Questions, and updated Privacy Policy.
+- We are committed to have full consistency between marketing promises and legally binding documents.
+
+**v5.7 is released:**
+
+- quantum resistant end-to-end encryption with all contacts.
+- forward and save messages without revealing the source.
+- in-call sounds and switching sound sources.
+- better network connection management.
+- customizable profile images.
+
+[Read More](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.html)
+
+## [The dangers of metadata in messengers](https://simplex.chat/blog/20240416-dangers-of-metadata-in-messengers.html)
+
+16 Apr 2024
+
+*By Esra'a al Shafei*
+
+It's important not to be complacent with the current standards of messaging, where metadata aggregation is still normalized in apps falsely and dangerously marketed as "private". This is a post exploring the fundamental differences between privacy and security.
+
+[Read More](https://simplex.chat/blog/20240416-dangers-of-metadata-in-messengers.html)
+
+## [Why I joined SimpleX Chat - by Esra'a al Shafei](https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html)
+
+04 Apr 2024
+
+*By Esra'a al Shafei*
+
+Transitioning from a lifelong career dedicated to nonprofits, including Board roles at organizations like the Wikimedia Foundation, Access Now and Tor, my decision to join SimpleX Chat may come as a surprise to some. But, as I step into this new chapter, I want to share the insights and convictions that have guided me here, shedding light on what I think sets SimpleX Chat apart and why this move feels like an essential learning opportunity.
+
+[Read More](https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html)
+
+## [SimpleX network: real privacy and stable profits, non-profits for protocols, v5.6 released with quantum resistant e2e encryption and simple profile migration](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html)
+
+23 Mar 2024
+
+**SimpleX network: deliver real privacy via a profitable business and non-profit protocol governance:**
+
+- community and business interests are aligned.
+- the journey to the decentralized non-profit protocol governance.
+- welcome, Esra'a!
+
+**v5.6 is released:**
+
+- quantum resistant end-to-end encryption (BETA) - enable it for the new contacts.
+- use the app during the audio and video calls.
+- migrate all app data to another device via QR code.
+- blocking members and many other improvements.
+
+[Read More](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html)
+
+## [SimpleX Chat v5.6 (beta): adding quantum resistance to Signal double ratchet algorithm](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html)
+
+14 Mar 2024
+
+This is a major upgrade for SimpleX Chat messaging protocols!
+
+This post also covers various aspects of end-to-end encryption:
+
+- Why do we need end-to-end encryption?
+- Why encryption is even allowed?
+- End-to-end encryption security: attacks and defence.
+- How secure is encryption in different messengers?
+- When can you start using quantum resistant chats?
+- Next for post-quantum crypto - all direct chats, small groups and security audit
+
+[Read More](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html)
+
+## [SimpleX Chat: free infrastructure from Linode, v5.5 released with private notes, group history and a simpler UX to connect.](https://simplex.chat/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html)
+
+24 Jan 2024
+
+**SimpleX Chat infrastructure on Linode:**
+
+- free infrastructure.
+- SimpleX servers in Linode Marketplace.
+- high capacity messaging servers.
+
+**v5.5 is released:**
+
+- private notes.
+- group history
+- simpler UX to connect to other people
+- message delivery, battery usage and other improvements
+
+Also, the app interface is now available in Hungarian and Turkish - thanks to our users.
+
+SimpleX Chat Android and desktop apps are now available in 20 languages!
+
+[Read More](https://simplex.chat/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html)
+
+## [SimpleX Chat v5.4 - link mobile and desktop apps via quantum resistant protocol, and much better groups.](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html)
+
+25 Nov 2023
+
+**v5.4 is released:**
+
+- Link mobile and desktop apps via secure quantum-resistant protocol. 🔗
+- Better groups: - faster to join and more reliable. - create groups with incognito profile. - block group members to reduce noise. - prohibit files and media in a group.
+- Better calls: faster to connect, with screen sharing on desktop.
+- Many other improvements.
+
+[Read More](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html)
+
+## [SimpleX Chat v5.3 released: desktop app, local file encryption and improved groups with directory service](https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html)
+
+25 Sep 2023
+
+**v5.3 is released:**
+
+- new desktop app! 💻
+- encrypt locally stored files & media
+- directory service and other group improvements
+- simplified incognito mode
+- better app responsiveness, stability and 40% reduced memory usage.
+- new privacy settings: show last messages & save draft.
+
+Also, our users added 6 new interface languages - Arabic*, Bulgarian, Finnish, Hebrew*, Thai and Ukrainian.
+
+* Android app only.
+
+[Read More](https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html)
+
+## [SimpleX Chat v5.2 released: message delivery receipts](https://simplex.chat/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html)
+
+22 Jul 2023
+
+**v5.2 is released:**
+
+- message delivery receipts! ✅
+- filter favorite and unread chats
+- better disappearing messages
+- prohibit message reactions
+- more usable groups: - view full original replied message in info. - share your address via your chat profile - search new and existing members
+- stability improvements: - keep your connections working after restoring from backup. - restart app (Android) or reconnect servers (iOS) - more stable connections and message delivery
+
+**Platform evolution:**
+
+- problems of public groups and their future
+- what about read receipts?
+
+[Read More](https://simplex.chat/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html)
+
+## [SimpleX Chat v5.1 released: message reactions and self-destruct passcode](https://simplex.chat/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html)
+
+23 May 2023
+
+**v5.1 is released:**
+
+- message reactions 🚀
+- improved messages: - voice messages up to 5 minutes - custom time to disappear - message editing history
+- new design and customizable themes you can share*!
+- self-destruct passcode
+
+Also, the app interface is now available in Japanese and Portuguese (Brazil)* - thanks to our users!
+
+* Android app only.
+
+[Read More](https://simplex.chat/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html)
+
+## [SimpleX Chat: vision and funding, v5.0 released with videos and files up to 1gb](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html)
+
+22 Apr 2023
+
+**SimpleX Chat vision and funding:**
+
+- why is it a commercial company?
+- how is it funded and what is the business model?
+- what is next?
+
+**v5.0 is released:**
+
+- send videos and files up to 1gb
+- app passcode independent from system authentication
+- networking improvements
+
+Also, the app interface is now available in Polish - thanks to our users.
+
+SimpleX Chat apps are now available in 10 languages!
+
+[Read More](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html)
+
+## [SimpleX Chat v4.6 – with hidden profiles, community moderation, improved audio/video calls and reduced battery usage.](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.html)
+
+28 Mar 2023
+
+v4.6 is released:
+
+- ARMv7a and Android 8+ - 2x more supported devices!
+- hidden chat profiles
+- community moderation
+- improved audio/video calls
+- reduced battery usage
+- SMP server monitoring: status bot and page
+
+Also, the app interface is now available in Chinese and Spanish - thanks to our users!
+
+[Read More](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.html)
+
+## [SimpleX File Transfer Protocol - a new protocol for sending large files efficiently, privately and securely.](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.html)
+
+01 Mar 2023
+
+CLI and relays implementing the new XFTP protocol are released - you can use them now!
+
+[Read More](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.html)
+
+## [SimpleX Chat v4.5 released – with multiple chat profiles, message draft, transport isolation and Italian language!](https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html)
+
+04 Feb 2023
+
+v4.5 is released:
+
+- multiple chat profiles!
+- message draft
+- transport isolation
+- reduced battery usage
+- private filenames
+
+Also, the app interface is now available in Italian - thanks to Weblate and our users!
+
+[Read More](https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html)
+
+## [SimpleX Chat v4.4 released – with disappearing messages, live messages, connection security verification and French language!](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.html)
+
+03 Jan 2023
+
+v4.4 is released:
+
+- disappearing messages!
+- live messages
+- connection security verification
+- support for GIFs and stickers
+
+Also, the app interface is now available in French - thanks to Weblate and our users!
+
+[Read More](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.html)
+
+## [SimpleX Chat reviews and v4.3 released – with instant voice messages, irreversible deletion of sent messages and improved server configuration.](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.html)
+
+06 Dec 2022
+
+SimpleX Chat November reviews:
+
+[Privacy Guides](https://www.privacyguides.org/real-time-communication/#simplex-chat) recommendations.
+
+[Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/).
+
+[The messenger matrix](https://www.messenger-matrix.de/).
+
+[Supernova review](https://supernovas.space/detailed_reviews.html#simplex) and [messenger ratings](https://supernovas.space/messengers.html).
+
+v4.3 is released:
+
+- instant voice messages!
+- irreversible deletion of sent messages for all recipients
+- improved SMP server configuration and support for server passwords
+- privacy and security improvements: protect app screen, SimpleX links security, etc.
+
+[Read More](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.html)
+
+## [Security assessment by Trail of Bits, the new website and v4.2 released](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html)
+
+08 Nov 2022
+
+*"Have you been audited or should we just ignore you?"*
+
+SimpleX Chat security has been assessed by [Trail of Bits](https://www.trailofbits.com/about), 4 issues were identified, and 3 of them are fixed in v4.2.
+
+The new website is live: [https://simplex.chat](https://simplex.chat/)
+
+v4.2 is released:
+
+- group links — admins can create the links for new members to join
+- auto-accept contact requests + configure whether to accept incognito and welcome message
+- small things: change group member role, mark chat as unread, send stickers and GIFs from Android keyboards.
+- manually switch contact or member to another address / server (BETA)
+- receive files faster (BETA)
+
+[Read More](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html)
+
+## [SimpleX Chat v4.0 with encrypted database is released](https://simplex.chat/blog/20220928-simplex-chat-v4-encrypted-database.html)
+
+28 Sep 2022
+
+Added:
+
+- encrypted local chat database — if you already use the app, you can encrypt the database in the app settings
+- support for self-hosted WebRTC ICE servers
+- improved stability of creating new connections: more reliable groups, files and contacts
+- deleting files and media — for security and to save storage
+- For developers — TypeScript SDK for integrating with SimpleX Chat
+- support animated images in Android app
+- German language in mobile apps UI
+
+[Read More](https://simplex.chat/blog/20220928-simplex-chat-v4-encrypted-database.html)
+
+## [SimpleX Chat v3.2 is released — meet Incognito mode, unique to Simplex Chat](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.html)
+
+01 Sep 2022
+
+Added:
+
+- Incognito mode — use a new random profile name for each contact
+- use .onion server addresses with Tor
+- endless scrolling and search
+- choose accent color and dark mode
+- reduced APK size for direct download and in F-Droid repo from 200 to 46Mb!
+
+[Read More](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.html)
+
+## [SimpleX Chat v3.1 is released — with secret groups and server access via Tor](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.html)
+
+08 Aug 2022
+
+Added:
+
+- finally, secret chat groups — nobody but members know they exist!
+- access to messaging servers via Tor on all platforms
+- advanced network settings to optimize traffic usage
+- published chat protocol
+- new app icons
+
+[Read More](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.html)
+
+## [SimpleX Chat v3.1-beta is released — improved battery/traffic usage](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html)
+
+23 Jul 2022
+
+Added:
+
+- terminal app: access to messaging servers via SOCKS5 proxy (e.g., Tor).
+- mobile apps: join and leave chat groups.
+- optimized battery and traffic usage — up to 90x reduction!
+- two docker configurations for self-hosted SMP servers.
+
+[Read More](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html)
+
+## [SimpleX announces SimpleX Chat v3 — with encrypted calls and iOS push notifications](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html)
+
+11 Jul 2022
+
+Added:
+
+- chat database export and import
+- end-to-end encrypted audio/video calls
+- protocol privacy and performance improvements
+
+Also read why having users' identifiers that all other platforms use is bad for the users, and how they reduce privacy.
+
+[Read More](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html)
+
+## [SimpleX Chat v2.2 - the new privacy and security features](https://simplex.chat/blog/20220604-simplex-chat-new-privacy-security-settings.html)
+
+04 Jun 2022
+
+Added:
+
+- protect your chats with SimpleX Lock
+- save data and avoid sharing you are online — manually accepting images
+- avoid visiting websites of the links you send — disable link previews
+- identify any lost messages in the chat
+
+[Read More](https://simplex.chat/blog/20220604-simplex-chat-new-privacy-security-settings.html)
+
+## [SimpleX Chat v2.1 - better conversation privacy](https://simplex.chat/blog/20220524-simplex-chat-better-privacy.html)
+
+24 May 2022
+
+Clear conversations without deleting contacts
+
+[Read More](https://simplex.chat/blog/20220524-simplex-chat-better-privacy.html)
+
+## [SimpleX Chat v2.0 - sending images and files in mobile apps](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.html)
+
+11 May 2022
+
+Read how SimpleX delivers messages without having user profile identifiers of any kind.
+
+[Read More](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.html)
+
+## [Instant notifications for SimpleX Chat mobile apps](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.html)
+
+04 Apr 2022
+
+Design of private instant notifications on Android and for push notifications for iOS.
+
+[Read More](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.html)
+
+## [SimpleX announces SimpleX Chat mobile apps for iOS and Android](https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.html)
+
+08 Mar 2022
+
+Brand new mobile apps with battle-tested Haskell core.
+
+[Read More](https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.html)
+
+## [SimpleX announces SimpleX Chat public beta for iOS](https://simplex.chat/blog/20220214-simplex-chat-ios-public-beta.html)
+
+14 Feb 2022
+
+Our first prototype of mobile UI for iOS is available!
+
+[Read More](https://simplex.chat/blog/20220214-simplex-chat-ios-public-beta.html)
+
+## [SimpleX announces SimpleX Chat v1](https://simplex.chat/blog/20220112-simplex-chat-v1-released.html)
+
+12 Jan 2022
+
+Major protocol changes address all design mistakes identified during concept review by an independent expert.
+
+[Read More](https://simplex.chat/blog/20220112-simplex-chat-v1-released.html)
+
+## [SimpleX announces SimpleX Chat v0.5](https://simplex.chat/blog/20211208-simplex-chat-v0.5-released.html)
+
+08 Dec 2021
+
+Support for long-term user addresses in terminal app.
+
+[Read More](https://simplex.chat/blog/20211208-simplex-chat-v0.5-released.html)
+
+## [SimpleX announces SimpleX Chat v0.4](https://simplex.chat/blog/20210914-simplex-chat-v0.4-released.html)
+
+14 Sep 2021
+
+Terminal app now supports groups and file transfers.
+
+[Read More](https://simplex.chat/blog/20210914-simplex-chat-v0.4-released.html)
+
+## [Announcing SimpleX Chat Prototype!](https://simplex.chat/blog/20210512-simplex-chat-terminal-ui.html)
+
+12 May 2021
+
+Prototype chat app for the terminal (console).
+
+[Read More](https://simplex.chat/blog/20210512-simplex-chat-terminal-ui.html)
+
+## [Simplex Chat](https://simplex.chat/blog/20201022-simplex-chat.html)
+
+22 Oct 2020
+
+The prototype of SimpleX Messaging Server implementing SMP protocol.
+
+[Read More](https://simplex.chat/blog/20201022-simplex-chat.html)
diff --git a/blog/20201022-simplex-chat.html b/blog/20201022-simplex-chat.html
index afff41140c..ed611297c4 100644
--- a/blog/20201022-simplex-chat.html
+++ b/blog/20201022-simplex-chat.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20201022-simplex-chat.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20201022-simplex-chat.md b/blog/20201022-simplex-chat.md
new file mode 100644
index 0000000000..01e5e808c3
--- /dev/null
+++ b/blog/20201022-simplex-chat.md
@@ -0,0 +1,17 @@
+# Simplex chat
+
+**Published:** Oct 22, 2020
+
+[https://simplex.chat](https://simplex.chat)
+
+I'd really appreciate your feedback, criticism and suggestions on the open-source idea I was slowly working on since early 2020. I recently made the demo server for the low-level message queue protocol ("simplex messaging protocol") and the website to try to explain the chat idea that would use this protocol.
+
+Haskell protocol implementation: [https://github.com/simplex-chat/simplexmq](https://github.com/simplex-chat/simplexmq)
+
+In short, the protocol defines a minimalist set of commands and server responses (just 7 commands and 5 responses sent over TCP) to operate encrypted message queues with in-memory persistence - the implementation uses STM.
+
+If anything, it was definitely helping to get to know Haskell types etc. much deeper than before :)
+
+Any criticism would be great - thank you in advance!
+
+Originally published at [https://www.reddit.com/r/haskell/comments/jg6uh4/simplex_chat/](https://www.reddit.com/r/haskell/comments/jg6uh4/simplex_chat/)
diff --git a/blog/20210512-simplex-chat-terminal-ui.html b/blog/20210512-simplex-chat-terminal-ui.html
index 80338935e2..7efa452684 100644
--- a/blog/20210512-simplex-chat-terminal-ui.html
+++ b/blog/20210512-simplex-chat-terminal-ui.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20210512-simplex-chat-terminal-ui.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20210512-simplex-chat-terminal-ui.md b/blog/20210512-simplex-chat-terminal-ui.md
new file mode 100644
index 0000000000..1a6bf52048
--- /dev/null
+++ b/blog/20210512-simplex-chat-terminal-ui.md
@@ -0,0 +1,23 @@
+# Announcing SimpleX Chat Prototype!
+
+**Published:** May 12, 2021
+
+For the last six months [me](https://github.com/epoberezkin) and my son Efim have been working to bring you a working prototype of SimpleX Chat. We're excited to announce SimpleX Chat terminal client is now available [here](https://github.com/simplex-chat/simplex-chat) on Linux, Windows and Mac (you can either build from source or download the binary for Linux, Windows or Mac from the latest release).
+
+We’ve been using the terminal client between us and a few other people for a couple of months now, eating our own “dog food”, and have developed up to version 0.3.1, with most of the messaging protocol features we originally planned
+
+## Features
+
+- End-to-end encryption with protection from man in the middle attack. The connection invitation must be passed out-of-band (see [how to use SimpleX Chat](https://github.com/simplex-chat/simplex-chat#how-to-use-simplex-chat) in the repo).
+- No global identity or any usernames visible to the server(s), ensuring full privacy of your contacts and conversations.
+- Message signing and verification with automatically generated RSA keys, with keys being unique per each connection.
+- Authorization of each command/message by the servers with automatically generated RSA key pairs, also unique per connection.
+- Message integrity validation (via passing the digests of the previous messages).
+- Encrypted TCP transport, independent of certificates.
+- You can deploy your own server, but you don’t have to - the demo SMP server to relay your messages is available at smp1.simplex.im:5223 (pre-configured in the client).
+
+## We need your help!
+
+We're building a new kind of chat network - the only network that lets you control your chat. We'd really appreciate your feedback, criticism and support - a star on the github repo, signing up to the mailing list or any contribution to the project will help. There is so much more to do!
+
+Originally published at [https://www.reddit.com/r/haskell/comments/naw6lz/simplex_chat_prototype_terminal_ui_made_in_haskell/](https://www.reddit.com/r/haskell/comments/naw6lz/simplex_chat_prototype_terminal_ui_made_in_haskell/)
diff --git a/blog/20210914-simplex-chat-v0.4-released.html b/blog/20210914-simplex-chat-v0.4-released.html
index 91a235210e..479ddc4159 100644
--- a/blog/20210914-simplex-chat-v0.4-released.html
+++ b/blog/20210914-simplex-chat-v0.4-released.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20210914-simplex-chat-v0.4-released.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20210914-simplex-chat-v0.4-released.md b/blog/20210914-simplex-chat-v0.4-released.md
new file mode 100644
index 0000000000..87eef6b63f
--- /dev/null
+++ b/blog/20210914-simplex-chat-v0.4-released.md
@@ -0,0 +1,41 @@
+# SimpleX announces SimpleX Chat v0.4
+
+**Published:** Sep 14, 2021
+
+## Open-source decentralized chat that uses privacy-preserving message routing protocol
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter. [SimpleX Chat](https://github.com/simplex-chat/simplex-chat) is our first application, a chat application built on the SimpleX platform that serves as an example of the power of the platform and as a reference application.
+
+## What is SimpleX?
+
+We recognised that there is currently no messaging application which respects user privacy and guarantees metadata privacy -- in other words, messages could be private, but a third party can always see who is communicating with whom by examining a central service and the connection graph. SimpleX, at it's core, is designed to be truly distributed with no central server. This allows for enormous scalability at low cost, and also makes it virtually impossible to snoop on the network graph.
+
+The first application built on the platform is Simplex Chat, which for now is terminal (command line) based with mobile apps in the pipeline. The platform can easily support a private social network feed and a multitude of other services, which can be developed by the Simplex team or third party developers.
+
+## What's new in v0.5?
+
+We're exicted to announce that SimpleX Chat now supports group chat and file transfer!
+
+### Chat groups
+
+To create a group use the `/g <group>` command. You can then invite contacts to the group by entering the `/a <group> <name>` command. Your contact(s) will need to use the `/j accept` command to accept the invitation to the group. To send messages to the group, simply enter `#<group> <message>`.
+
+**Please note:** Groups are not stored on any server; they are maintained as a list of members in the app database. Sending a message to the group sends a message to each member of the group.
+
+![simplex-chat](https://simplex.chat/images/groups.gif)
+
+### File transfer
+
+Sharing files is simple! To send a file to a contact, use the `/f @<contact> <file_path>` command. The recipient will have to accept before the file is sent.
+
+![simplex-chat](https://simplex.chat/images/files.gif)
+
+## We're always looking for help!
+
+We'd really appreciate your comments, criticism and support - a star on the GitHub repo, downloading and testing the chat or any contribution to the project will help a lot – thank you for all your support!
+
+**Please note:** SimpleX Chat is in early stage development: we are still iterating protocols, improving privacy and security, so if you have communication scenarios requiring high security, you should consider some other options for now.
+
+Our goal is to create a new kind of chat platform that lets you control your chat!
+
+Originally published at [https://www.reddit.com/r/selfhosted/comments/poal79/simplex_chat_an_opensource_decentralized_chat/](https://www.reddit.com/r/selfhosted/comments/poal79/simplex_chat_an_opensource_decentralized_chat/)
diff --git a/blog/20211208-simplex-chat-v0.5-released.html b/blog/20211208-simplex-chat-v0.5-released.html
index 11e0661e88..3c3911fa4c 100644
--- a/blog/20211208-simplex-chat-v0.5-released.html
+++ b/blog/20211208-simplex-chat-v0.5-released.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20211208-simplex-chat-v0.5-released.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20211208-simplex-chat-v0.5-released.md b/blog/20211208-simplex-chat-v0.5-released.md
new file mode 100644
index 0000000000..35e3dcc79f
--- /dev/null
+++ b/blog/20211208-simplex-chat-v0.5-released.md
@@ -0,0 +1,31 @@
+# SimpleX announces SimpleX Chat v0.5
+
+**Published:** Dec 08, 2021
+
+## Simplex Chat is the first chat platform that is 100% private by design - SimpleX no access to your connections graph
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter. [SimpleX Chat](https://github.com/simplex-chat/simplex-chat) is our first application, a chat application built on the SimpleX platform that serves as an example of the power of the platform and as a reference application.
+
+## What is SimpleX?
+
+We recognised that there is currently no messaging application which respects user privacy and guarantees metadata privacy -- in other words, messages could be private, but a third party can always see who is communicating with whom by examining a central service and the connection graph. SimpleX, at it's core, is designed to be truly distributed with no central server. This allows for enormous scalability at low cost, and also makes it virtually impossible to snoop on the network graph.
+
+The first application built on the platform is Simplex Chat, which for now is terminal (command line) based with mobile apps in the pipeline. The platform can easily support a private social network feed and a multitude of other services, which can be developed by the Simplex team or third party developers.
+
+## What's new in v0.5?
+
+### Long-term chat addresses
+
+Users can now create long-term chat addresses that they can share with many people (e.g. in email signature, or online), so that any chat user can send them a connection request.
+
+This is an ALPHA feature, and we have not yet added any protection against spam contact requests. However, if the address you created starts receiving spam connection requests, you can simply delete it without losing any of your accepted connections and create another address - as many times as you like!
+
+## We need your help!
+
+We'd really appreciate your comments, criticism and support - a star on the GitHub repo, downloading and testing the chat or any contribution to the project will help a lot – thank you for all your support!
+
+**Please note:** SimpleX Chat is in early stage development: we are still iterating protocols, improving privacy and security, so if you have communication scenarios requiring high security, you should consider some other options for now.
+
+Our goal is to create a new kind of chat platform that lets you control your chat!
+
+Originally published at [https://www.reddit.com/r/haskell/comments/rc0xkn/simplex_chat_the_first_chat_platform_that_is_100/](https://www.reddit.com/r/haskell/comments/rc0xkn/simplex_chat_the_first_chat_platform_that_is_100/)
diff --git a/blog/20220112-simplex-chat-v1-released.html b/blog/20220112-simplex-chat-v1-released.html
index cac5b81e24..670cc5a086 100644
--- a/blog/20220112-simplex-chat-v1-released.html
+++ b/blog/20220112-simplex-chat-v1-released.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220112-simplex-chat-v1-released.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220112-simplex-chat-v1-released.md b/blog/20220112-simplex-chat-v1-released.md
new file mode 100644
index 0000000000..72a4280262
--- /dev/null
+++ b/blog/20220112-simplex-chat-v1-released.md
@@ -0,0 +1,53 @@
+# SimpleX announces SimpleX Chat v1
+
+**Published:** Jan 12, 2022
+
+## The most private and secure chat and application platform
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter. [SimpleX Chat](https://github.com/simplex-chat/simplex-chat) is our first application, a messaging application built on the SimpleX platform.
+
+## What is SimpleX?
+
+There is currently no messaging application which respects user privacy and guarantees metadata privacy - in other words, messages could be private, but a third party can always see who is communicating with whom by examining a central service and the connection graph. SimpleX, at it's core, is designed to be truly distributed with no central server. This allows for enormous scalability at low cost, and also makes it virtually impossible to snoop on the network graph.
+
+The first application built on the platform is Simplex Chat, which for now is terminal (command line) based with mobile apps in the pipeline. The platform can easily support a private social network feed and a multitude of other services, which can be developed by the Simplex team or third party developers.
+
+## What's new in v1?
+
+### Stable protocol implementation
+
+All releases from v1 onwards will be forwards and backwards compatible.
+
+### Message encryption has been completely re-engineered to provide forward secrecy and recovery from break-in.
+
+SimpleX Chat v1 now uses:
+
+- [double-ratchet](https://www.signal.org/docs/specifications/doubleratchet/) E2E encryption using AES-256-GCM cipher with [X3DH key agreement](https://www.signal.org/docs/specifications/x3dh/) using 2 ephemeral Curve448 keys to derive secrets for ratchet initialization. These keys and secrets are separate for each contact, group membership and file transfer.
+- in addition to double ratchet, there is a separate E2E encryption in each message queue with DH key exchange using Curve25519 and [NaCl crypto-box](https://nacl.cr.yp.to/index.html) - separate E2E encryption has been added to avoid having any cipher-text in common between message queues of a single contact (to prevent traffic correlation).
+- additional encryption of messages delivered from servers to recipients, also using Curve25519 DH exchange and NaCl crypto-box - to avoid shared cipher-text in sent and received traffic (also to prevent traffic correlation).
+
+### Improved user and server authentication and transport
+
+SimpleX now uses ephemeral Ed448 keys to sign and verify client commands to the servers. As before, these keys are different per message queue and do not represent a user's identity.
+
+Instead of ad-hoc encrypted transport we now use TLS 1.2+ limited to the most performant and secure cipher with forward secrecy (ECDHE-ECDSA-CHACHA20POLY1305-SHA256), Curve448 groups and Ed448 keys.
+
+Server identity is validated as part of TLS handshake - the fingerprint of offline server certificate is used as a permanent server identity which is included in server address, to protect against MITM attacks between clients and servers.
+
+SimpleX also uses [tls-unique channel binding](https://datatracker.ietf.org/doc/html/rfc5929#section-3) in each signed client command to the server to protect against replay attacks.
+
+### Changes in protocol encoding
+
+We switched from inefficient text-based low level protocol encodings, that simplified early development, to space and performance efficient binary encodings, reducing protocol overhead from circa 15% to 3.7% of transmitted application message size.
+
+## Learn more about Simplex
+
+Further details on platform objectives and technical design are available [here](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
+
+SimpleX Chat client can be used in the terminal on all major desktop platforms (Windows/Mac/Linux) and also on Android devices with [Termux](https://github.com/termux).
+
+SimpleX also allows people to host their own servers and own their own chat data. SimpleX servers are exceptionally lightweight and require a single process with the initial memory footprint of under 20 Mb, which grows as the server adds in-memory queues (even with 10,000 queues it uses less than 50Mb, not accounting for messages).
+
+## We look forward to you using it!
+
+We look forward to your feedback and suggestions - via GitHub issues or via SimpleX Chat - you can connect to the team with `/simplex` command once you run the chat.
diff --git a/blog/20220214-simplex-chat-ios-public-beta.html b/blog/20220214-simplex-chat-ios-public-beta.html
index 49cfbcd168..3201d6271c 100644
--- a/blog/20220214-simplex-chat-ios-public-beta.html
+++ b/blog/20220214-simplex-chat-ios-public-beta.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220214-simplex-chat-ios-public-beta.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220214-simplex-chat-ios-public-beta.md b/blog/20220214-simplex-chat-ios-public-beta.md
new file mode 100644
index 0000000000..608b4ab736
--- /dev/null
+++ b/blog/20220214-simplex-chat-ios-public-beta.md
@@ -0,0 +1,42 @@
+# SimpleX announces SimpleX Chat public beta for iOS
+
+**Published:** Feb 14, 2022
+
+## Private and secure chat and application platform - [public beta is now available](https://testflight.apple.com/join/DWuT2LQu) for iPhones with iOS 15.
+
+Our new iPhone app is very basic - right now it only supports text messages and emojis.
+
+Even though the app is new, it uses the same core code as our terminal app, that was used and stabilized over a long time, and it provides the same level of privacy and security that has been available since the release of v1 a month ago:
+
+- [double-ratchet](https://www.signal.org/docs/specifications/doubleratchet/) E2E encryption.
+- separate keys for each contact.
+- additional layer of E2E encryption in each message queue (to prevent traffic correlation when multiple queues are used in a conversation - something we plan later this year).
+- additional encryption of messages delivered from servers to recipients (also to prevent traffic correlation).
+
+You can read more details in our recent [v1 announcement](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md).
+
+## Join our public beta!
+
+Install the app [via TestFlight](https://testflight.apple.com/join/DWuT2LQu), connect to us (via **Connect to SimpleX team** link in the app) and to a couple of your friends you usually send messages to - and please let us know what you think!
+
+We would really appreciate any feedback to improve the app and to decide which additional features should be included in our public release in March.
+
+Should it be:
+
+- images,
+- link previews,
+- or maybe something else we couldn't think of.
+
+Please vote on the features you think are the most needed in our [app roadmap](https://app.loopedin.io/simplex).
+
+## What is SimpleX?
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter.
+
+We aim to provide the best possible protection of messages and metadata. Today there is no messaging application that works without global user identities, so we believe we provide better metadata privacy than alternatives. SimpleX is designed to be truly distributed with no central server, and without any global user identities. This allows for high scalability at low cost, and also makes it virtually impossible to snoop on the network graph.
+
+The first application built on the platform is Simplex Chat, which is available for terminal (command line in Windows/Mac/Linux) and as iOS public beta - with Android app coming in a few weeks. The platform can easily support a private social network feed and a multitude of other services, which can be developed by the Simplex team or third party developers.
+
+SimpleX also allows people to host their own servers to have control of their chat data. SimpleX servers are exceptionally lightweight and require a single process with the initial memory footprint of under 20 Mb, which grows as the server adds in-memory queues (even with 10,000 queues it uses less than 50Mb, not accounting for messages). It should be considered though that while self-hosting the servers provides more control, it may reduce meta-data privacy, as it is easier to correlate the traffic of servers with small number of messages coming through.
+
+Further details on platform objectives and technical design are available [in SimpleX platform overview](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
diff --git a/blog/20220308-simplex-chat-mobile-apps.html b/blog/20220308-simplex-chat-mobile-apps.html
index e1ddd908ae..bd21853e2f 100644
--- a/blog/20220308-simplex-chat-mobile-apps.html
+++ b/blog/20220308-simplex-chat-mobile-apps.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220308-simplex-chat-mobile-apps.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220308-simplex-chat-mobile-apps.md b/blog/20220308-simplex-chat-mobile-apps.md
new file mode 100644
index 0000000000..6fa4774357
--- /dev/null
+++ b/blog/20220308-simplex-chat-mobile-apps.md
@@ -0,0 +1,67 @@
+# SimpleX announces SimpleX Chat mobile apps for iOS and Android
+
+**Published:** March 8, 2022
+
+## SimpleX Chat is the first chat platform that is 100% private by design - it has no access to your connections graph
+
+We have now released iPhone and Android apps to [Apple AppStore](https://apps.apple.com/us/app/simplex-chat/id1605771084) and [Google Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app), [APK for Android](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex.apk) is also available for direct download.
+
+**Please note**: the current version is only supported on iPhone 8+ and on Android 10+ - we are planning to add support for iPad and older devices very soon, and we will announce it on our [Reddit](https://www.reddit.com/r/SimpleXChat/) and [Twitter](https://twitter.com/SimpleXChat) channels - please subscribe to follow our updates there.
+
+## What is SimpleX
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter.
+
+We aim to provide the best possible protection of messages and metadata. Today there is no messaging application that works without global user identities, so we believe we provide better metadata privacy than alternatives. SimpleX is designed to be truly distributed with no central server, and without any global user identities. This allows for high scalability at low cost, and also makes it virtually impossible to snoop on the network graph.
+
+The first application built on the platform is Simplex Chat. The platform can easily support a private social network feed and a multitude of other services, which can be developed by the Simplex team or third party developers.
+
+Further details on platform objectives and technical design are available [in SimpleX platform overview](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
+
+## Why we are building it
+
+Evgeny (SimpleX Chat founder): I have been working on this platform for a long time to provide a place where all people can communicate freely with each other, without fear of persecution because of what they said and who they are connected with. Not sharing information about your connections is very important, particularly for people living in oppressive regimes. Because of the terrible conflict between Russia and Ukraine, people of both countries – I have friends and family there – could be at risk when sharing their opinions or just from being connected to people who were prosecuted. Every messenger app that knows who you are can end up sharing all of your connections with undesirable third parties, either as a result of a court order or as a result of attack - so even Signal, which has strong encryption, cannot protect your connection graph. I hope our messenger can help people living in the oppressive regimes to express their opinions without fear and risk of prosecution.
+
+## Huge thanks to our testers!
+
+Thanks a lot to everybody who helped testing and improving the apps!
+
+If you have a [TestFlight version](https://testflight.apple.com/join/DWuT2LQu) installed you can continue using it.
+
+We plan to keep it as stable as we can, and it will give you access to all new features 1-2 weeks earlier - it's limited to 10,000 users, so you can grab it while it's available. You can still communicate with people who use a public version – we are committed to maintaining backwards compatibility.
+
+You can always migrate from a public App Store version to a TestFlight version. The opposite migration - from TestFlight to public version - is only possible when we have the same app versions released, as there are usually some database migrations that cannot be reversed. To migrate to public version you have to disable automatic updates on TestFlight, wait until public version catches up and then install it from App Store. In any case, it is safe installing the public version, but it might crash if you have a newer version from TestFlight - in this case you just need to re-install the app from TestFlight and install App Store version a bit later - you would not lose any of your data.
+
+## It's not all new - our core code has been used for a long time by a few thousand people in our terminal app.
+
+The apps use the same core code as our terminal app, that was used and stabilized over a long time, and it provides the same level of privacy and security that has been available since the release of v1 earlier this year:
+
+- [double-ratchet](https://www.signal.org/docs/specifications/doubleratchet/) E2E encryption.
+- separate keys for each contact.
+- additional layer of E2E encryption in each message queue (to prevent traffic correlation when multiple queues are used in a conversation - something we plan later this year).
+- additional encryption of messages delivered from servers to recipients (also to prevent traffic correlation).
+
+You can read more technical details in our recent [v1 announcement](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md).
+
+A big thank you to [@angerman](https://github.com/angerman) for making it possible to compile our Haskell code to mobile platforms and getting it approved on app stores - it has been a non-trivial project, and it is still ongoing.
+
+## Install the apps and make a private connection!
+
+Once you install the app, you can connect to anybody:
+
+1. Create your local chat profile - it is not shared with SimpleX servers, it is local to your devices, and it will be shared with your contacts when you connect.
+2. To make a private connection, you need to create a one-time connection link / QR code via "Add contact" button in the app. You can either show the QR code to your contact in person or via a video call - this is the most secure way to create a connection - or you can share the link via any other channel - only one user can connect via this link.
+3. Once another user scans the QR code or opens the app via the link (they also should create their profile first) the connection will be created and you can send e2e encrypted messages privately, without anybody knowing you are connected.
+
+## New features and improvements that are coming soon
+
+- push notification server. Currently the apps load messages in the background periodically, that can be quite infrequent on iOS if you don't open the app regularly. With push notifications you would know about the new messages instantly.
+- e2e encrypted audio and video calls via WebRTC.
+- export and import of the chat database.
+- "reply to message" - feature allowing you to quote the message you are replying to.
+- localization - we will let you know once you can contribute the translations to your languages.
+- configuring your servers in the apps - this will be released this week, both for iOS and Android. By default the apps are using SimpleX Chat servers, but you will be able to configure your own and still be connected to other users who use our app with our servers.
+- user profile images.
+- sending images and files - image preview will be sent via the servers, so it can be asynchronous, and large files/full resolution images via WebRTC, so both devices will have to be online.
+
+Please let us know what else you think is important and if you find any bugs.
diff --git a/blog/20220404-simplex-chat-instant-notifications.html b/blog/20220404-simplex-chat-instant-notifications.html
index 63b03b94a5..53be0c64a0 100644
--- a/blog/20220404-simplex-chat-instant-notifications.html
+++ b/blog/20220404-simplex-chat-instant-notifications.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220404-simplex-chat-instant-notifications.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220404-simplex-chat-instant-notifications.md b/blog/20220404-simplex-chat-instant-notifications.md
new file mode 100644
index 0000000000..27ac381ec2
--- /dev/null
+++ b/blog/20220404-simplex-chat-instant-notifications.md
@@ -0,0 +1,123 @@
+# Instant notifications for SimpleX Chat mobile apps
+
+**Published:** April 04, 2022
+
+## SimpleX Chat is the first chat platform that is 100% private by design - it has no access to your connections
+
+Since we released SimpleX Chat mobile apps couple of weeks ago we've had a lot of excitement from our users - nearly 2000 people downloaded the app after [the announcement](https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.md)!
+
+Huge thanks to everybody who downloaded and connected to us via the chat - there were many great questions and suggestions, and on some days I spent most of the time chatting to our users :)
+
+Since we released the app, we've added and released:
+
+- support for iPhone 7.
+- configurable SimpleX servers.
+- message replies, editing and deletion.
+- profile images.
+- and, most importantly, private instant message notifications on Android devices - more on that below.
+
+## Install the apps and make a private connection!
+
+Once you install the app, you can connect to anybody:
+
+1. Create your local chat profile - it is not shared with SimpleX servers. It is local to your devices, and it will be shared with your contacts only when you connect.
+2. To make a private connection, you need to create a one-time connection link or a QR code via the "Add contact" button in the app. You can show the QR code to your contact in person or via a video call - this is the most secure way to create a connection - or you can share the link via any other channel. Only one user can connect via this link.
+3. Once another user scans the QR code or opens the app via the link the connection will be created and you can send end-to-end encrypted messages privately, without anybody knowing you are connected.
+
+See [demo video](https://youtu.be/rZeVhsv_JAY) that shows how two users connect and send the first messages.
+
+## Why we are doing it
+
+We are building SimpleX Chat because we believe that privacy is a fundamental human right, and that protecting our personal network of contacts is even more important than the content of the messages - sharing this network can lead to various adverse consequences, from manipulating us into buying goods we don't need, manipulating election processes, and in some cases, prosecuting innocent people. For example, [Mohamedou Ould Salahi](https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi) was detained in Guantanamo prison for 15 years after a single "wrong" phone call. His story is told in his memoir and in The Mauritanian movie.
+
+## Problem - users expect to be instantly notified when messages arrive!
+
+Our first users realized that what we take for granted in messaging apps - instant message notifications - is missing in our first release of SimpleX Chat apps. Quite a few people thought that it was a bug, rather than a missing feature. Sorry to disappoint!
+
+## Why can't we just do what messenger X does?
+
+SimpleX Chat is the first and the only messenger we know of that operates without user identities of any kind. There are no phone numbers, emails, usernames, public keys, or any other addresses or identifiers to uniquely identify the users to the network or servers. That is why we say it is 100% private by design, and fundamentally different than other chat platforms.
+
+Instead, SimpleX Chat assigns these identifiers to unidirectional message queues. What looks to SimpleX Chat users like contacts and groups [1], to SimpleX servers looks like an unorganized and unrelated collection of unidirectional message queues. Our servers do not know which queues belong to which users, contacts or groups. Even a single conversation can happen via two different servers (one for sent and another for received messages). This makes our personal network of contacts invisible to the servers.
+
+But it also creates a problem for instant notifications - all push notification services require having a device token.
+
+So, how can we operate without identities and still have instant notifications?
+
+[1] yes, we have groups in our terminal app, and the UI to manage them is coming to mobile apps soon. Some users have already firgured out how to [create groups via chat console](https://medium.com/@vsevolod.mineev/how-to-collaborate-across-multiple-devices-whilst-protecting-your-metadata-371af87d0ba0).
+
+## We've cracked it for Android!
+
+After some research into how push notifications work on Android, and open-source alternatives to Google push notifications, we discovered how to avoid sharing device tokens with any servers.
+
+We have implemented message reception as a background service (in Android terminology, a "foreground service" showing a notification icon when the service is running) following the same design as [ntfy.sh](https://github.com/binwiederhier/ntfy-android) created by [Philipp Heckel](https://github.com/binwiederhier), who, in turn, credits the design to [the blog post by Roberto Huertas](https://robertohuertas.com/2019/06/29/android_foreground_services/). Big thanks to them!
+
+How does it work? When the app is first started on an Android device, it starts the background service that keeps the TCP connections to the messaging servers open with almost no traffic (only doing periodic checks that connections still exist). It consumes only a few percents of battery per day, depending on how stable your internet connection is, and delivers message notifications as soon as messages arrive.
+
+This service continues running when the app is switched off, and it is restarted when the device is restarted even if you don't open the app - so the message notifications arrive instantly every time. To maximize battery life, it can be turned off by switching off "Private notifications". You will still receive notifications while the app is running or in the background.
+
+So, for Android we can now deliver instant message notifications without compromising users' privacy in any way. The app version 1.5 that includes private instant notifications is now available on [Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app), in our [F-Droid repo](https://app.simplex.chat/) and via direct [APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex.apk) downloads!
+
+Please let us know what needs to be improved - it's only the first version of instant notifications for Android!
+
+## iOS notifications require a server
+
+iOS is much more protective of what apps are allowed to run on the devices, and the solution that worked on Android is not viable on iOS.
+
+We already have background refresh in the iOS app that periodically checks for new messages, and if you use the app every day it delivers notifications within 10 or 20 minutes. It is not instant, but it may be usable for some. If you use the app infrequently, however, this delay can become several hours, or your phone may stop checking for the new messages completely. This is not ideal!
+
+The only solution known to us is using Apple's push notifications service (APN) to deliver push notifications.
+
+We planned for it, so we added to [v1 of SMP](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md) (the protocol used by our servers) an extension allowing the client to subscribe to notifications from message queues, via separate queue addresses, and using separate cryptographic keys for each queue. This has to be enabled by the client for each queue separately. We haven't used this extension so far, and now we are building a SimpleX notification service based on it.
+
+If the user enables push notifications, then for each contact the app would enable a notification subscription and pass credentials to the notification server together with the device token required to deliver push notifications to user's device.
+
+The notification server will subscribe to these notifications from SMP servers. The notifications do not include any message content, only the signal that a message has arrived to the server. Notification server is only allowed to send 2-3 hidden notifications per hour to the device. The notification is end-to-end encrypted and contains information about which server has a message, so that the client can connect to the server, retrieve and decrypt the message, and show the notification to the users including sender name and the message content. None of this information is shared with any server.
+
+If the user receives more than 2-3 messages per hour, the notification server can send additional visible notifications that would simply say "you have a new message", and the user will have to open the app to receive and see these messages. We are also investigating whether we can use "mutable-content" notifications that allow doing some processing when the notification arrives before showing it to the users.
+
+It is a substantial amount of development, we are aiming to release it later this month.
+
+This design is a compromise between privacy and convenience. The notification server will have to have a device token to deliver notifications. Several things we did (or plan to do) to improve this compromise:
+
+1. The notification server will only store device tokens and queue addresses in memory, making it more complex for a potential attacker to access. If server has to be restarted, they would lose all configured notification subscriptions and the clients would have to create them again. We will program the clients to periodically check for the existence of notification subscriptions on the notification server.
+2. The notificaiton server will not know the addresses of the messaging queues used to receive or send messages. A different address is used to subscribe to notifications. So while the notification server would have the knowledge of how many queues your device has (and on which servers), it still won't know who is sending you the messages.
+3. We are also planning to split the logic of notification subscriptions and delivering notifications to the devices to two different servers. The server that subscribes to the notifications could be self-hosted, allowing you full control of how you deploy it. Only this server would know which messaging servers you use or how many messaging queues you have. The server that delivers notifications to the devices will be managed by SimpleX Chat as we have to authorize it with Apple's push notification service. This split will not be available in the first release. We plan to add it a bit later.
+
+So, with the notification servers added, our network design will look like this:
+
+```
+  User's iOS device                Internet                        Servers
+---------------------   |   ------------------------   |   -------------------------
+                        |                              |
+                        |                              |   (can be self-hosted now)
++--------------+        |                              |      +----------------+
+| SimpleX Chat |       -------------- TLS ---------------     | SimpleX        |
+|    client    |------> SimpleX Messaging Protocol (SMP) ---> | Messaging      |
++--------------+       ----------------------------------     | Server         |
+     ^    |             |                              |      +----------------+
+     |    |             |                              |            |   |
+     |    |             |                              |            | S | T
+     |    |             |                              |            | M | L
+     |    |             |                              |            | P | S
+     |    |             |                              |            |   |
+     |    |             |                              |      +----------------+       +----------------+
+     |    |            -------------- TLS ---------------     | SimpleX        |       | SimpleX        |
+     |    |----------->     Notifications management    ----> | Notifications  | ----> | Push           |
+     |                 ----------------------------------     | Subscriber     |       | Server         |
+     |                  |                              |      +----------------+       +----------------+
+     |                  |                              |     (can be self-hosted                |
+     |                  |                              |        in the future)                  |
+     |                  |                              |                                        V
+     |                 -------------- TLS ---------------                              +-----------------+
+     |-----------------       Notification delivery     <----------------------------- | Apple PN server |
+                       ----------------------------------                              +-----------------+
+                        |                              |
+```
+
+Please let us know what you think about this design and about this privacy / usability trade-off:
+
+- For you, is this an acceptable compromise, if you can choose to disable instant notifications?
+- Do you have any ideas about how this design could be improved upon?
+
+Thank you!
diff --git a/blog/20220511-simplex-chat-v2-images-files.html b/blog/20220511-simplex-chat-v2-images-files.html
index cf5d0e5d8a..4e6f4edbb3 100644
--- a/blog/20220511-simplex-chat-v2-images-files.html
+++ b/blog/20220511-simplex-chat-v2-images-files.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220511-simplex-chat-v2-images-files.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220511-simplex-chat-v2-images-files.md b/blog/20220511-simplex-chat-v2-images-files.md
new file mode 100644
index 0000000000..c218c941f4
--- /dev/null
+++ b/blog/20220511-simplex-chat-v2-images-files.md
@@ -0,0 +1,37 @@
+# SimpleX Chat v2.0 - sending images and files in mobile apps
+
+**Published:** May 11, 2022
+
+## New in version 2.0 - sending images and files privately
+
+To send image and files SimpleX Chat uses privacy-preserving system components, both in iOS and Android apps. We do not ask for permission to access multiple or selected files, as, for example, Signal and Telegram do - it compromises either privacy or convenience.
+
+How does it work? The gallery and files are accessed from a system provided dialogue that runs in a separate process, and provides a temporary URI to access only one file selected by the user, only until the app is restarted.
+
+To make file and images work for mobile apps we made a breaking change in SimpleX Chat core. The current version can exchange files with the previous version 1.6 of the terminal app, but not with the version before that.
+
+In the mobile app, to send and receive files both devices must have version 2.0 installed - so please check it with your contacts. Receiving images works in the previous version, so even if your contacts did not yet upgrade the app, they should be able to receive the images.
+
+## The first messaging platform without user identifiers
+
+To protect identities of users and their connections, SimpleX Chat has no user identifiers visible to the network – unlike any other messaging platform.
+
+Many people asked: _if SimpleX has no user identifiers, how can it deliver messages?_
+
+To deliver mesages, instead of user IDs used by all other platforms, SimpleX has identifiers for message queues, separate for each of your contacts. In the current version of the protocol each queue is used until the contact is deleted. Later this year we plan to add queue rotation to the client protocol, so that even conversations don't have long term identifiers visible to the network. This design prevents leaking any users metadata on the application level.
+
+You define which server(s) to use **to receive** the messages, your contacts – the servers you use **to send** the messages to them. It means that every conversation is likely to use two different servers - one for each message direction.
+
+Only client devices store user profiles, contacts, groups, and messages sent with **2-layer end-to-end encryption**.
+
+Read more in [SimpleX whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
+
+## How to connect with your contacts in SimpleX Chat
+
+Once you install the app, you can connect to anybody:
+
+1. Create your local chat profile - it is not shared with SimpleX servers. It is local to your devices, and it will be shared with your contacts only when you connect.
+2. To make a private connection, you need to create a one-time connection link or a QR code via the app. You can show the QR code to your contact in person or via a video call - this is the most secure way to create a connection - or you can share the link via any other channel. Only one user can connect via this link.
+3. Once another user scans the QR code or opens the app via the link the connection will be created and you can send end-to-end encrypted messages privately, without anybody knowing you are connected.
+
+<img src="../images/conversation.png" alt="Make a private connection" width="594" height="360">
diff --git a/blog/20220524-simplex-chat-better-privacy.html b/blog/20220524-simplex-chat-better-privacy.html
index bb05a4cb3e..84609d6cb3 100644
--- a/blog/20220524-simplex-chat-better-privacy.html
+++ b/blog/20220524-simplex-chat-better-privacy.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220524-simplex-chat-better-privacy.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220524-simplex-chat-better-privacy.md b/blog/20220524-simplex-chat-better-privacy.md
new file mode 100644
index 0000000000..174661a3be
--- /dev/null
+++ b/blog/20220524-simplex-chat-better-privacy.md
@@ -0,0 +1,17 @@
+# SimpleX Chat v2.1 - better conversation privacy
+
+**Published:** May 24, 2022
+
+## New in version 2.1 - clearing conversations without deleting contacts
+
+In this version you can irreversibly delete individual messages after they were deleted by a sender, and also completely clear the conversation.
+
+The only way to do it before this version was by deleting the contact, now you can keep the connection when you clear the conversation.
+
+<img src="./images/20220524-clear-chat1.png" width="240"> <img src="./images/20220524-clear-chat2.png" width="240">
+
+See [v1 announcement](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md) for information on how SimpleX protects the security of the messages.
+
+See [v2 announcement](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md) for more information about SimpleX platform and how it works.
+
+Read about SimpleX design in [whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
diff --git a/blog/20220604-simplex-chat-new-privacy-security-settings.html b/blog/20220604-simplex-chat-new-privacy-security-settings.html
index af57f7044d..843e9745f9 100644
--- a/blog/20220604-simplex-chat-new-privacy-security-settings.html
+++ b/blog/20220604-simplex-chat-new-privacy-security-settings.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220604-simplex-chat-new-privacy-security-settings.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220604-simplex-chat-new-privacy-security-settings.md b/blog/20220604-simplex-chat-new-privacy-security-settings.md
new file mode 100644
index 0000000000..aaced7a2c7
--- /dev/null
+++ b/blog/20220604-simplex-chat-new-privacy-security-settings.md
@@ -0,0 +1,46 @@
+# SimpleX Chat v2.2 - the new privacy and security features
+
+**Published:** June 4, 2022
+
+See [v2 announcement](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md) for more information about SimpleX platform and how it protects your privacy by avoiding user identities of any kind in its design - SimpleX, unlike any other messaging platform, has no identity keys or any numbers that identify its users.
+
+## New Privacy and Security settings in version 2.2
+
+<img src="./images/20220604-privacy-settings.png" width="480">
+
+### Protect your chats
+
+To protect your chats you can enable SimpleX Lock. Every time you open the chat after it was in the background for 30 second, you will need to pass biometric or pin code authentication to use the app (provided it is enabled for your device).
+
+### Save data and avoid sharing you are online
+
+In case you want to save your mobile data or to avoid showing to your contacts that you are online, you can disable automatic image downloads. For many users it is more convenient to have images downloaded automatically, so it is enabled by default.
+
+Low resolution image previews would still be shown, the senders have no way to see if you received them or not.
+
+### Avoid visiting websites of the links you send
+
+When you receive the links that include link previews, it is fully private - these previews are generated by the sender, and they do not expose your IP address in any way.
+
+When you send the links, the app automatically downloads the link description and the picture from the website of the link. While it is convenient, it exposes your IP address to the website. To avoid it you can disable sending link previews.
+
+### Identify any lost messages in the chat
+
+The app tracks the integrity of the messages you receive by cheching their sequential numbers and by validating that the hash of the previous message matches the hash included in the message – each conversation, effectively, is two blockchains that only you and your contact have access to.
+
+In case some of the messages are lost, you would see it in the chat. It can happen because of one the following reasons:
+
+- the messages have expired on the server after 30 days not being delivered.
+- the messages were removed when the server was restarted. We will add server redundancy later this year to avoid message loss in this case, for now if you see an indication that some messages were lost in the chat, you can check with your contact what it was.
+- some other app error. Please notify us via chat - we will investigate possible root causes.
+- the connection is compromised. This is very unlikely, but not an impossible scenario.
+
+### There is more
+
+You can discover additional features we are currently testing in Experimental Features - they will be announced later!
+
+## More information
+
+See [v1 announcement](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md) for information on how SimpleX protects the security of the messages.
+
+Read about SimpleX design in [whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
diff --git a/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html b/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html
index 43c08f7ca9..af9081c145 100644
--- a/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html
+++ b/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md b/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md
new file mode 100644
index 0000000000..857a8f791e
--- /dev/null
+++ b/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md
@@ -0,0 +1,97 @@
+# SimpleX announces SimpleX Chat v3 - with encrypted calls and iOS push notifications
+
+**Published:** Jul 11, 2022
+
+## New in version 3
+
+- [instant notifications for iOS](#instant-notifications-for-ios)
+- [end-to-end encrypted audio/video calls](#end-to-end-encrypted-audiovideo-calls)
+- [database export and import](#database-export-and-import)
+- [protocol privacy and performance improvements](#protocol-privacy-and-performance-improvements)
+
+### Instant notifications for iOS
+
+I wrote previously about [our design for iOS notifications](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md#problem---users-expect-to-be-instantly-notified-when-messages-arrive) - this is now released. The app will offer to migrate the database when updated, and then you need to choose notifications mode – instant or periodic push notifications, or previously available periodic background refresh that does not use push notifications.
+
+To deliver the notifications to iOS devices we use our notification server, as there is a single private key that Apple issues for the app. This server has minimal amount of information about your chat activity:
+
+- it does not have the addresses of messaging queues used to send and receive messages - there is an additional address used for notification server to receive notifications from the messaging servers.
+- notifications themselves do not include message content or contacts, even in encrypted form - they only contain end-to-end encrypted metadata about the server and the queue that has available messages - so Apple servers cannot access the information about how many contacts you have or how frequently each of them messages you - they can only see the total number of notifications your device receives.
+- message senders do not connect to the notification server, so it cannot in any way correlate sent and received traffic across multiple devices.
+
+<img src="./images/20220711-notifications.png" width="480">
+
+**Please note**: for periodic notifications to work the app has to be in the background - if the app is completely stopped (removed from the recent apps), it will not check the new messages and you will not receive notifications. Instant notifications work even when the app is completely stopped.
+
+### End-to-end encrypted audio/video calls
+
+You can now call your contacts via WebRTC, connecting via SimpleX Chat relay servers or peer-to-peer, and in the near future you will be able to configure your own STUN/TURN servers used to establish the connection. The calls are end-to-end encrypted - the key is negotiated via the connection you already have with your contact in the chat, that is also used as a signalling layer for WebRTC - in most cases only three messages in total have to be sent by your and your contact's clients for the call to start, including the initial call invitation.
+
+<img src="./images/20220711-call-in-progress.png" width="480">
+
+The calls are still quite limited, especially on iOS, - for example, you cannot continue the call while the app is in the background.
+
+### Database export and import
+
+Quite a few users asked - _how can I move my chat profile to a new device_? SimpleX Chat v3 has a solution for that - you can now export chat database from one device and import it into another - even to another platform, e.g. you can move chat database from Android phone to iOS or to the terminal (console) client.
+
+<img src="./images/20220711-database-chat-stopped.png" width="480">
+
+Some important limitations:
+
+- you cannot run the same chat profile from two devices, neither at the same time nor in turns. You should only use the latest database version - every time you want to move it to another device you need to export a new chat archive from the device that was the latest to use it, and import it to the device where you want to use it next.
+- we plan to add internal database encryption soon, but currently it is stored on the device without encryption, and the exported archive is also not encrypted. You should store it securely, and encrypt it if you store it in the cloud or send via email.
+
+This feature can be useful in some other scenarios:
+
+- managing multiple chat profiles - it's not very convenient, and a better support of multiple profiles is coming soon.
+- share access to the same profile with other people, as long as it is not used at the same time. For that use case it may be better to run SimpleX Chat terminal client in the cloud, as we do with our public account that you can connect to via the app.
+- preserve chat profile when you need to temporarily delete the app from your device.
+
+### Protocol privacy and performance improvements
+
+Adding push notifications for iOS required SimpleX Messaging Protocol changes. We managed not just to keep the same level of meta-data privacy from passive observers, but to improve it - now all message meta-data that is passed from the server to the recipient is included into the same encrypted envelope as the message itself - as before, there is no identifiers or ciphertext in common inside TLS traffic between received and sent traffic of the server, and now there is no message timestamp inside TLS as well.
+
+We also improved the protocol flow for establishing bidirectional connection between two users - it is substantially faster now, consuming much less network traffic and battery. It improves the time it takes to connect to your contacts and to start delivering images and files.
+
+All these changes did not affect backward compatibility - if your contact has the previous version of the client, or you are connecting to a previous version of the server, the previous version of the protocol will be used - SimpleX has independent version negotiation in 4 protocol layers [since v1](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md#stable-protocol-implementation), allowing us to evolve the protocols without any disruption to the users.
+
+## SimpleX platform
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter. [SimpleX Chat](https://github.com/simplex-chat/simplex-chat) is our first application, a messaging application built on the SimpleX platform.
+
+### The first (and we believe the only) messaging platform without user identifiers of any kind - 100% private by design!
+
+To protect identities of users and their connections, SimpleX Chat has no user identifiers visible to the servers and the network – unlike any other messaging platform. Not only SimpleX doesn't use phone numbers or emails, as Signal and many other platforms, it also does not have any persistent identifiers to identify users - unlike many other messengers considered private - Session, Cwtch, Ricochet, Briar, Jami, etc., - all these platforms have global user identifiers, uniquely identifying their users and creating the risks of de-anonymising the users.
+
+### Why having users' identifiers is bad for the users?
+
+When each user has a unique identifier on the platform, even if this is just a random number, e.g. as a Session ID, it creates risks that whoever gains access to the platform data can observe how the users are connected and how many messages are transmitted between them, and then correlate this information with the existing public social networks, determining the real identities of some users. Even with the most private messengers built on top of Tor network, having a persistent identity means that if you talk to two different users via the same profile they can prove that they communicate with the same person, as they would use the same address to send messages.
+
+SimpleX platform avoids these risks by not having any user identity in its design - so even if you talk to two different people from the same chat profile, they would not be able to prove they are talking to the same person - only that user profiles look the same. And we are planning to add a feature allowing to have a different display name for each contact you connect to - quite a few users asked for it.
+
+### How does it work
+
+Many people asked: _if SimpleX has no user identifiers, how can it deliver messages?_
+
+I wrote about it in [v2 release announcement](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md) and you can get more information about SimpleX platform objectives and technical design in [the whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
+
+## We ask you to help us pay for 3rd party security audit
+
+I will get straight to the point: I ask you to support SimpleX Chat with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support we were lucky to have so far.
+
+We are planning a 3rd party security audit for the app, and it would hugely help us if some part of this $20000+ expense could be covered with donations.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations for the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+If you are already using SimpleX Chat, or plan to use it in the future when it has more features, please consider making a donation - it will help us to raise more funds. Donating any amount, even the price of the cup of coffee, would make a huge difference for us.
+
+It is possible to [donate via GitHub](https://github.com/sponsors/simplex-chat), which is commission-free for us, or [via OpenCollective](https://opencollective.com/simplex-chat), that also accepts donations in crypto-currencies, but charges a commission.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html b/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html
index acfe8a028a..2a0d99c4f1 100644
--- a/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html
+++ b/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md b/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md
new file mode 100644
index 0000000000..06d4a22981
--- /dev/null
+++ b/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md
@@ -0,0 +1,112 @@
+# SimpleX Chat v3.1-beta is released - improved battery/traffic usage
+
+**Published:** Jul 23, 2022
+
+## What's new
+
+- terminal app: [access to messaging servers via SOCKS5 proxy](#terminall-app-access-to-messaging-servers-via-socks5-proxy--tor) (e.g., Tor).
+- mobile apps: [join and leave chat groups](#mobile-apps-join-and-leave-chat-groups).
+- [optimized battery and traffic usage - up to 90x reduction!](#optimized-battery-and-traffic-usage---up-to-90x-reduction).
+- [two docker configurations for self-hosted SMP servers](#docker-configuration-for-self-hosted-smp-servers).
+
+### Terminall app: access to messaging servers via SOCKS5 proxy / Tor
+
+<img src="./images/20220723-tor.jpg" width="480">
+
+While SMP protocol is focussed on protecting application-level meta-data by using pairwise connection identifiers instead of user identifiers (that are used by all other messaging platforms), there are scenarios when it is important for the users to protect their IP addresses from the servers - quite a few users have been somewhat disappointed that we didn't add it earlier.
+
+This release of terminal app supports accessing the servers via Tor, but the servers themselves are still available on their usual addresses. We are planning to add .onion addresses (v3 hidden service) to all messaging servers we provide, and the users who self-host the servers will also be able to have dual servers addresses - so that one party in the conversation can access the servers via .onion address without necessarily requiring that the other party uses Tor as well.
+
+To access SimpleX servers via Tor you need to install Tor proxy and run simplex-chat with `-x` option. See [terminal app docs](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/CLI.md#access-messaging-servers-via-tor-beta) for more information.
+
+As this is a beta release, to install it you need to use this command:
+
+```sh
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | sh -s -- v3.1.0-beta.0
+```
+
+### Mobile apps: join and leave chat groups
+
+<img src="./images/20220723-group-invite.png" width="330"> <img src="./images/20220723-group-accept.png" width="330"> <img src="./images/20220723-group-leave.png" width="330">
+
+Groups have been supported by SimpleX Chat core for a very long time, but there was no user interface in the mobile apps to use them - users had to use chat console to create groups, add members, and accept invitations.
+
+This release allows accepting the invitations to join groups via mobile apps UI, making it much easier to create groups - only one user (a group owner) needs to use chat console, while all other groups members just need to tap a button in the UI to join or leave the group. Full group UI is coming in v3.1 in 1-2 weeks, but you can already start using groups today by installing beta-versions of mobile apps via [TestFlight](https://testflight.apple.com/join/DWuT2LQu), [Google PlayStore Beta](https://play.google.com/apps/testing/chat.simplex.app) and [APK download](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex.apk).
+
+To manage groups via terminal app or via chat console in the mobile apps you have to use these commands:
+
+- to create group: `/g <group_name> [<description>]`
+- to add member (admin by default): `/a <group_name> <contact_name> [owner/admin/member]`
+- to remove member from the group: `/rm <group_name> <contact_name>`
+
+Accepting group invitations, leaving and deleting groups no longer requires using console commands.
+
+### Optimized battery and traffic usage - up to 90x reduction
+
+To reduce battery and traffic usage this release updated SMP protocol to allow batching multiple server commands (up to 90!) into one traffic block – provided both the server and the client are upgraded. It means that if you have 90 contacts (or group members) on one server, to subscribe to all messaging queues you now need to send only one 16kb block instead of ~1.5Mb of traffic (90 blocks). It also hides how many contacts you have from any attackers who observe your network.
+
+You might notice that sending commands to multiple queues in one block would allow the server to correlate that all these queues belong to the same user, even though the current server implementation we use does not do it. But even without batching, as the commands are sent via the same TCP connection, this correlation was already possible, so compared with the previous version it has no downsides.
+
+To mitigate the risk of servers correlating your messaging queues we will soon add an option to access each queue via a separate TCP connection, which will have to be used together with access via Tor (as otherwise the servers would still see the same IP address). While it will increase battery and traffic consumption, it will also provide the highest level of privacy.
+
+### Docker configuration for self-hosted SMP servers
+
+When we released SimpleX Chat v3 two weeks ago many users wanted to host messaging servers in docker containers. So, we are now offering [two versions of docker configurations](https://github.com/simplex-chat/simplexmq/tree/stable/scripts/docker):
+
+- fast and convenient - it downloads SMP server binary from GitHub.
+- more secure - it builds SMP server from the source code.
+
+Let us know how it works for you!
+
+## SimpleX platform
+
+We are building a new platform for distributed Internet applications where privacy of the messages _and_ the network matter. [SimpleX Chat](https://github.com/simplex-chat/simplex-chat) is our first application, a messaging application built on the SimpleX platform.
+
+### The first (and the only?) messaging platform without user identifiers of any kind - 100% private by design!
+
+To protect identities of users and their connections, instead of user identifiers visible to the servers and/or the network (that are used by all other messaging platforms), SimpleX Chat uses [pairwise identifiers](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of connections between the users – there are two queues in each connection, each queue having 2 different identifiers to send and to receive the messages. It increases the number of used identifiers to the square of the number of users, making it more difficult (or impossible) to determine who is talking to whom. I [wrote previously](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users) why it is bad for the users' privacy to have any identifiers, even random numbers, associated with their profiles.
+
+### If SimpleX has no user identifiers, how can it deliver messages?
+
+I wrote about it in [v2 release announcement](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md) and you can get more information about SimpleX platform objectives and technical design in [the whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md).
+
+### Privacy: technical details and limitations
+
+SimpleX design follows "defence in depth" security principles having multiple overlapping defensive mechanisms to protect users privacy and security:
+
+- TLS transport with server identity validation and channel binding, limited to the most secure cryptographic algorithms.
+- Three levels of encryption that both protect message content and meta-data, preventinc trafic correlation even if TLS is compromised:
+  - end-to-end encryption in each messaging queue.
+  - end-to-end encryption of the conversation using double-ratchet algorithms, that provides OTR messaging with forward secrecy and break-in recovery.
+  - additional encryption layer between the server and message recipient, to prevent traffic correlation by ciphertext or any identifiers.
+- Four levels of message padding to prevent any attack based on the content size - the TLS transport block is padded to a fixed 16kb size, and each of 3 encrypted envelopes is padded to a constant size before encryption as well.
+
+What we plan to add soon to further improve privacy and security:
+
+- message queue rotation, so that pairwise identifiers become temporary, and your conversations move from server to server automatically.
+- access to the messaging servers via Tor v3 hidden services.
+- message mixing - adding latencies to message delivery, to protect against traffic correlation by message time.
+- using Tor v3 hidden service addresses for messaging servers.
+- passphrase-based local database encryption.
+
+SimpleX Chat [README page](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#privacy-technical-details-and-limitations) has more details about it.
+
+## We ask you to help us pay for 3rd party security audit
+
+I will get straight to the point: I ask you to support SimpleX Chat with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support we were lucky to have so far.
+
+We are planning a 3rd party security audit for the app, and it would hugely help us if some part of this $20000+ expense could be covered with donations.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations for the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+If you are already using SimpleX Chat, or plan to use it in the future when it has more features, please consider making a donation - it will help us to raise more funds. Donating any amount, even the price of the cup of coffee, would make a huge difference for us.
+
+It is possible to [donate via GitHub](https://github.com/sponsors/simplex-chat), which is commission-free for us, or [via OpenCollective](https://opencollective.com/simplex-chat), that also accepts donations in crypto-currencies, but charges a commission.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20220808-simplex-chat-v3.1-chat-groups.html b/blog/20220808-simplex-chat-v3.1-chat-groups.html
index 07d435ecfd..8d43e3cd4a 100644
--- a/blog/20220808-simplex-chat-v3.1-chat-groups.html
+++ b/blog/20220808-simplex-chat-v3.1-chat-groups.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220808-simplex-chat-v3.1-chat-groups.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220808-simplex-chat-v3.1-chat-groups.md b/blog/20220808-simplex-chat-v3.1-chat-groups.md
new file mode 100644
index 0000000000..aabc3bac50
--- /dev/null
+++ b/blog/20220808-simplex-chat-v3.1-chat-groups.md
@@ -0,0 +1,112 @@
+# SimpleX Chat v3.1 is released - with secret groups and server access via Tor
+
+**Published:** Aug 8, 2022
+
+## What's new
+
+- [secret chat groups](#secret-chat-groups)!
+- [access to messaging servers via Tor](#access-messaging-servers-via-tor)
+- [advanced network settings](#advanced-network-settings)
+- [published chat protocol](#published-chat-protocol)
+- [new app icons](#new-app-icons)
+- [other changes since v3](#other-changes-since-v3):
+  - optimized battery and traffic usage - up to 90x reduction!
+  - two docker configurations for self-hosted SMP servers
+
+### Secret chat groups
+
+<img src="./images/20220808-group1.png" width="330"> <img src="./images/20220808-group2.png" width="330"> <img src="./images/20220808-group3.png" width="330">
+
+It's been [nearly a year](https://simplex.chat/blog/20210914-simplex-chat-v0.4-released.md) since the users of SimpleX Chat terminal app started experimenting with the groups, and now it is available to mobile app users as well. Many bugs were fixed, the stability was improved, but there are both the features we need to add and the bugs we need to fix to make groups more useful - we really look forward to your feedback. You can send any suggestions via the app by choosing `Chat with the developers` via app Settings (or using `/simplex` command in the terminal app) – this would connect you to SimpleX team via its [fixed chat address](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D).
+
+SimpleX network is decentralized, so how do groups work? Unlike Matrix or Signal that host the group profile and the list of group members on their servers, SimpleX servers have no information about the group's existence - only its members do. SimpleX network does not assign any globally unique identifiers to the group, there is only a local database identifier and the list of members stored on members' devices. A user has an independent connection to each member in a group. When a user sends a message to the group, the app sends this message independently to each member. You can read more about how groups work in [SimpleX Chat Protocol](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/protocol/simplex-chat.md#sub-protocol-for-chat-groups).
+
+But how can it scale, you might ask? It simply won't, and the current design for the groups is only suitable for relatively small groups of people who know each other well, definitely not larger than few hundred members – this design prioritized privacy and security of the group over its size or performance. For example, to send a message to the group of 100 members a user would need to send a total of ~1.6mb of data (as each message uses a fixed size block of 16kb). And if you were to send a 1mb file then it would also require sending it 100 times (provided each member accepts it).
+
+What if you need to send many large files to group members? We will be developing a file hosting server where the users will be able to upload the file (or image) once, and only send the file link and credentials to all group members, without the need to send the actual file. A small hosting quota will be available to all users for free, paid for by donations, and for larger files or to increase the total quota the users would either have to pay a small hosting cost or to self-host this server – it will be available as an open-source code.
+
+What if you need to have a large group - e.g. 100,000 members or more? We will be introducing SimpleX channels later this year, that can be both public and private. These channels would require a server to host them, either provided by SimpleX Chat or self-hosted - same as for a website. If this is a public channel it would be optionally accessible via the web browser as well, and it will be possible to embed it into any webpage.
+
+Other group improvements we will add soon:
+
+- manage notifications in each group independently.
+- search for messages - it is useful for direct conversations too, but more important for groups.
+
+### Access messaging servers via Tor
+
+<img src="./images/20220808-tor1.png" width="330">   <img src="./images/20220808-tor2.png" width="330">
+
+SimpleX protocols are focussed on protecting application-level meta-data – they don't have any user identifiers used by all other messaging platforms, instead relying on pairwise connection identifiers.
+
+But there are scenarios when users need to protect their IP addresses from the servers and any network observers – this is best done by using Tor to access any network services.
+
+This release allows to access SimpleX messaging servers via Tor on all platforms:
+
+- terminal app beta supported it for a couple weeks now: to access SimpleX servers via Tor you need to install Tor proxy and run simplex-chat with `-x` option. See [terminal app docs](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/CLI.md#access-messaging-servers-via-tor-beta) for more information.
+- Android app supports access via Tor using Orbot SOCKS proxy. Once you install and start Orbot, you need to enable `Network & Servers / Use SOCKS proxy` setting in the app to access SimpleX servers via Tor.
+- iOS app can also be used with Orbot iOS app (that is installed as a system-wide VPN provider). The only setting you might need to change is to increase network timeouts in the app - to do that you have to enable `Developer tools`, and then chose `Network & Servers / Advanced network settings / Set timeouts for proxy`.
+
+Currently all servers are accessed via their public Internet addresses, and while users can self-host messaging servers on .onion addresses (as v3 hidden services), it would require both connected contacts to use Tor. We are planning to add support for dual server addresses very soon, to allow the same server to be accessed both via its public Internet address and via .onion address, so that users can access servers without exiting Tor (via .onion address), but their contacts can access the same servers without using Tor.
+
+### Advanced network settings
+
+To reduce traffic on slow networks we added network access settings. To use these settings, you need to first enable `Developer tools` and then choose `Network & Servers / Advanced network settings`:
+
+- if your connections to the servers are unstable, and you frequently see the spinners in the list of chats, please increase the connection and protocol timeouts - it should reduce the traffic, but it may also make the app a bit slower when your Internet connection is slow.
+- if your connection to the servers appears stable, but the traffic usage is high, please try disabling TCP keep-alive setting or increasing keep-alive idle period (`TCP_KEEP_IDLE`) and interval (`TCP_KEEP_INTVL`).
+
+Once we investigated how these settings affect traffic and user experience we will simplify them - huge thanks to everyone testing them and reporting any traffic issues.
+
+### New app icons
+
+<img src="./images/20220808-icons.png" width="330">
+
+Many users asked to allow customizing the app, this is just a start - you can now choose either light or dark icon option via `Appearance` settings.
+
+More options to customize the app are coming - please let us know what are the most important.
+
+### Published chat protocol
+
+The [low level SimpleX protocols](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/) were published long time ago, and updated to reflect the evolution of the protocols, the high level chat protocol was not published before. The reason for that was to allow us to iterate it quickly, without committing to any of the decisions.
+
+This is the [first draft of SimpleX Chat Protocol](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/protocol/simplex-chat.md) - let us know any questions or suggestions.
+
+### Other changes since v3
+
+Since v3 release we also optimized battery and traffic usage - with up to 90x traffic reduction in some cases – and published two docker configurations for self-hosted SMP servers. Read more about it in the previous [beta version announcement](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md).
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md#privacy-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+## We ask you to help us pay for 3rd party security audit
+
+I will get straight to the point: I ask you to support SimpleX Chat with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support we were lucky to have so far.
+
+We are planning a 3rd party security audit for the app, and it would hugely help us if some part of this $20000+ expense could be covered with donations.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations for the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+If you are already using SimpleX Chat, or plan to use it in the future when it has more features, please consider making a donation - it will help us to raise more funds. Donating any amount, even the price of the cup of coffee, would make a huge difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat): it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat): it also accepts donations in crypto-currencies, but charges a commission.
+- Monero wallet: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20220901-simplex-chat-v3.2-incognito-mode.html b/blog/20220901-simplex-chat-v3.2-incognito-mode.html
index 00e32aa014..44c761003d 100644
--- a/blog/20220901-simplex-chat-v3.2-incognito-mode.html
+++ b/blog/20220901-simplex-chat-v3.2-incognito-mode.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220901-simplex-chat-v3.2-incognito-mode.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220901-simplex-chat-v3.2-incognito-mode.md b/blog/20220901-simplex-chat-v3.2-incognito-mode.md
new file mode 100644
index 0000000000..39e464ba7c
--- /dev/null
+++ b/blog/20220901-simplex-chat-v3.2-incognito-mode.md
@@ -0,0 +1,98 @@
+# SimpleX Chat v3.2 is released - meet Incognito mode, unique to Simplex Chat
+
+**Published:** Sep 1, 2022
+
+## What's new
+
+- [Incognito mode](#incognito-mode)
+- [assign names to your contacts](#assign-names-to-your-contacts)
+- [use .onion server addresses with Tor](#using-onion-server-addresses-with-tor)
+- [endless scrolling and search in chats](#endless-scrolling-and-search-in-chats)
+- [choose accent color and dark mode](#choose-accent-color-and-dark-mode)
+- disable notifications per contact / group
+- on Android:
+  - swipe to reply
+  - reduced APK size for direct download and in F-Droid repo from 200 to 50Mb!
+
+[Implementation audit is arranged for October](#we-ask-you-to-help-us-pay-for-3rd-party-security-audit)!
+
+### Incognito mode
+
+<img src="./images/20220901-incognito1.png" width="330"> <img src="./images/20220901-incognito2.png" width="330"> <img src="./images/20220901-incognito3.png" width="330">
+
+_SimpleX is already private, so why do we need an incognito mode_, you may ask.
+
+You indeed can choose a pseudonym as your main profile name, but there are several problems:
+
+- many users want to have their real name as their main profile, so that their friends recognise them. SimpleX objective is to provide anonymity from the network operators, but not necessarily from your contacts.
+- even if you choose a pseudonym, it would be used for all your contacts. And if two of them meet, while they cannot prove they are talking to the same person, as they use different addresses in SimpleX network to send you the messages, they could _suspect it_.
+- any pseudonym you manually choose leaks some information about you, as it's not really random.
+
+You could also use multiple chat profiles - currently you can only switch between them via export/import, we will make it easier very soon! But there are problems with multiple profiles too:
+
+- if you make many anonymous connections, each in its own user profile, you would end up having too many profiles - it is very inconvenient to manage.
+- sometimes, as your relationship with your contact evolves, you may want to share your main profile with them and have them among your friends - multiple profiles don't make it possible.
+
+So, the new Incognito mode allows having a new random name shared with each new contact, while having them all in the same user profile, and without the hassle of managing it manually. It's like a private mode in the browsers, where you can temporarily enable it when you connect to somebody you don't trust, and then disable it when connecting to the friend who knows you. It can be turned on via the app settings - see the pictures.
+
+I don't know any other messenger with this feature, and I always wanted to have this mode, so we are really looking forward to your feedback about it!
+
+### Assign names to your contacts
+
+You can now change the name under which your contacts appear in the chats. This is particularly useful when somebody connected to you using a random name – you can change it to be related to the context of the connection.
+
+### Using .onion server addresses with Tor
+
+<img src="./images/20220901-onion1.png" width="330">   <img src="./images/20220901-onion2.png" width="330">
+
+We have released support for using SOCKS proxy to access messaging servers via Tor, but previously the servers were still available via their public Internet addresses. It means that while your IP address was protected from the server, the whole Tor circuit could have been observed by some actors, and for some communication scenarios it is not desirable.
+
+This release adds support for servers with multiple hostnames - all servers provided by SimpleX Chat now have dual addresses (one public and one .onion), and you can have your own servers available via two addresses as well - all you have to do is to install Tor client on your server and register its address with Tor. If you server has both public and .onion address, it is not really hidden, so you should enable HiddenServiceSingleHopMode to reduce the latency of connection - it protects anonymity of the people who connect to the server, but not of the server itself. The server address would include both its public and onion address, as you can see in the server addresses in the app (in the contacts pages) - you should use the same format for the addresses of your servers.
+
+Both android and iOS app allow managing whether .onion addresses are used, and you can also enforce using .onion addresses - in this case the app will not connect to the server unless one of its hostname is .onion address. On Android, .onion addresses are used by default when SOCKS proxy is enabled.
+
+### Endless scrolling and search in chats
+
+Now you can access the full chat history via the app - it's embarrassing how long it took us to add it! And you can search the messages as well.
+
+### Choose accent color and dark mode
+
+Many of you said that blue is the worst possible color, so you can now make the app buttons and links look like you want! My favourite colours are green and orange.
+
+And you can choose dark or light mode independently of the system settings.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md#privacy-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+## We ask you to help us pay for 3rd party security audit
+
+Our great news is that we have already signed the agreement and paid for the security audit!
+
+It is planned in October, and if there are no major issues we will publish this report straight away, otherwise - once we fix them.
+
+This is a major expense for use - over $20,000 - I would really appreciate if you could help us cover some part of this cost with the donations.
+
+Our promise to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We will be establishing a legal framework this year to ensure that it doesn't change if the ownership of SimpleX Chat Ltd changes at any future point.
+
+Please consider making a donation - it will help us to raise more funds. Donating any amount, even the price of the cup of coffee, would make a huge difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat): it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat): it also accepts donations in crypto-currencies, but charges a commission.
+- Monero wallet: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20220928-simplex-chat-v4-encrypted-database.html b/blog/20220928-simplex-chat-v4-encrypted-database.html
index 7dc366305e..a3f218ef63 100644
--- a/blog/20220928-simplex-chat-v4-encrypted-database.html
+++ b/blog/20220928-simplex-chat-v4-encrypted-database.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20220928-simplex-chat-v4-encrypted-database.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20220928-simplex-chat-v4-encrypted-database.md b/blog/20220928-simplex-chat-v4-encrypted-database.md
new file mode 100644
index 0000000000..c802750bd9
--- /dev/null
+++ b/blog/20220928-simplex-chat-v4-encrypted-database.md
@@ -0,0 +1,132 @@
+# SimpleX Chat v4 with encrypted local database is released
+
+**Published:** Sep 28, 2022
+
+## What's new in v4
+
+- [encrypted local chat database](#local-chat-database-encryption).
+- [support for self-hosted WebRTC ICE servers](#self-hosted-webrtc-ice-servers).
+- [improved stability of creating new connections: more reliable groups, files and contacts](#improved-stability-of-creating-new-connections).
+- [deleting files and media](#deleting-files-and-media).
+- [For developers - TypeScript SDK for integrating with SimpleX Chat](#for-developers---typescript-sdk-for-integrating-with-simplex-chat) (e.g., chat bots or chat assistants).
+- animated images in Android app.
+- disable messages per contact / group in terminal app (it is already supported in mobile apps).
+
+Also, this version adds German language to mobile apps UI - huge thanks to [Michael](https://github.com/mlanp) who contributed them!
+
+Other new features since v3:
+
+- secret chat groups (see details in [v3.1 announcement](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.md#secret-chat-groups) - they are fully decentralized, only their members know these groups exist.
+- accessing messaging servers via Tor with support for .onion server addresses (see details in [v3.1](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.md#access-messaging-servers-via-tor) and [v3.2](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#using-onion-server-addresses-with-tor) announcements) - to protect users anonymity on the TCP transport level.
+- Incognito mode - sharing a random profile name with each new contact, to completely eliminate any shared data between them (see details in [v3.2](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#incognito-mode) announcement).
+- endless scrolling and search in chats.
+- reduced Android APK size for direct download and in F-Droid repo from 200 to 50Mb!
+
+[Implementation audit is arranged for October](#we-ask-you-to-help-us-pay-for-3rd-party-security-audit)!
+
+### Local chat database encryption
+
+<img src="./images/20220928-passphrase.png" width="330">
+
+SimpleX Chat focus has always been on protecting messages in delivery, not when they are stored on the device. This release changes it - now all messages that you receive and send are stored on the device encrypted with [SQLCipher](https://github.com/sqlcipher/sqlcipher).
+
+**Please note**: If you are already using SimpleX Chat, your database will remain unencrypted until you enter the passphrase via the app settings. You have to remember the passphrase you choose, as there is no way to recover it if it is lost.
+
+By default your passphrase will be stored securely on the device (in KeyChain on iOS or encrypted with the key stored in TPM, if available, on Android) - it is only accessible to the app, and only on one device. Storing passphrase is required for instant notifications to work. In this case, if you lose the passphrase, the app will continue to work, but you will not be able to change the passphrase and to migrate your user profile to another device.
+
+For additional security of your messages you also have the option to remove the passphrase from the device. In this case you will need to enter the passphrase every time you start the app. The notifications will continue to work only while the app is in the background. For iOS it means that periodic and local notifications will work, but instant notifications will only show that there is a message available, but not message content or who it is from - you will need to open the app and enter the passphrase to see the messages. In this case, if you lose the passphrase, you will not be able to open the app or decrypt the database - so make sure you store it safely.
+
+### Self-hosted WebRTC ICE servers
+
+<img src="./images/20220928-ice-servers.png" width="330">
+
+You could make audio and video calls via SimpleX Chat WebRTC servers since [v3](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#end-to-end-encrypted-audiovideo-calls) - that meant that our servers could observe your IP addresses. This release adds configuration to use your own STUN/TURN servers, helping you protect your privacy.
+
+See [this guide](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/WEBRTC.md) to learn how to deploy your own `coturn` server and to configure the mobile apps to use it.
+
+### Improved stability of creating new connections
+
+Secret groups made SimpleX Chat much more useful, but because SimpleX groups are completely decentralized and for them to work each member should connect to all other members, sometimes these connections fail and the group becomes fragmented - some members do not receive all messages. That was more common for larger groups, as the number of required member connections is O(n^2) of the group size.
+
+The reason for that problem was that some network operations required for group connections were not retried. This release improves stability of all network operations - receiving messages, making new contact connections, receiving files and connecting to members in the groups you join.
+
+### Deleting files and media
+
+<img src="./images/20220928-files-media.png" width="330">
+
+While the database with messages and all contacts is now encrypted, the files you receive and send are not (we are planning to improve it later). To protect the security of the files we have added an option to delete all files from the app storage - just make sure not to do it before the files you send are delivered to the recipients, or they won't receive them.
+
+### For developers - TypeScript SDK for integrating with SimpleX Chat
+
+It's been quite some time since it's been possible to create a chat-bot using SimpleX Chat as a library - but you had to either write Haskell code or use foreign function interface in any other language.
+
+With v4 we are announcing [TypeScript SimpleX Chat Client SDK](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript) that you can use to create any integrations with SimpleX Chat CLI.
+
+You can run SimpleX Chat CLI as a local WebSockets server on any port, we use 5225 here:
+
+```bash
+simplex-chat -p 5225
+```
+
+Then you can create a JavaScript or TypeScript application that would connect to it and control it via a simple WebSocket API. TypeScript SDK defines all necessary types and convenience functions to use in your applications. See this [sample bot](https://github.com/simplex-chat/simplex-chat/blob/stable/packages/simplex-chat-client/typescript/examples/squaring-bot.js) and README page.
+
+SimpleX Chat API allows you to:
+
+- create and change user profile (although in most cases you would do it manually, via SimpleX Chat terminal app).
+- create and accept invitations or connect with the contacts.
+- create and manage long-term user address, accepting connection requests from the code or automatically.
+- create, join and manage groups - this can be used, for example, to connect two different people who connected to chat-bot.
+- send and receive files.
+
+Some possible applications you can create:
+
+- peer-to-peer trading bots, that would connect people with matching buy/sell orders,
+- bots to access information,
+- language translation bots,
+- etc.
+
+As SimpleX Chat protocols provide strong encryption and authorization of the connections, you could use it not only in various communication scenarios, but also to remotely control any equipment where high level of security is required, for example:
+
+- smart home automation,
+- network services,
+- remote deletion of application data,
+- etc.
+
+We are really looking forward to seeing what applications you create - please submit your ideas and implementations, we will publish the links on a separate page on the website and GitHub repository.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md#privacy-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+## We ask you to help us pay for 3rd party security audit
+
+We have already signed the agreement and paid for the security audit!
+
+It is planned for October, and if there are no major issues we will publish this report straight away, otherwise - once we fix them.
+
+This is a major expense for use - over $20,000 - I would really appreciate if you could help us cover some part of this cost with the donations.
+
+Our promise to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We will be establishing a legal framework this year to ensure that it doesn't change if the ownership of SimpleX Chat Ltd changes at any future point.
+
+Please consider making a donation - it will help us to raise more funds. Donating any amount, even the price of the cup of coffee, would make a huge difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat): it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat): it also accepts donations in crypto-currencies, but charges a commission.
+- Monero wallet: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+- Bitcoin wallet: bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html b/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html
index a98e623f9e..bd957b26eb 100644
--- a/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html
+++ b/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md b/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md
new file mode 100644
index 0000000000..e6a0d442a8
--- /dev/null
+++ b/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md
@@ -0,0 +1,179 @@
+# Security assessment by Trail of Bits, the new website and v4.2 released
+
+**Published:** Nov 8, 2022
+
+## Security assessment by Trail of Bits
+
+<img src="./images/20221108-trail-of-bits.jpg" width=240>
+
+When we first launched the app in March the response on Reddit was: _"Have you been audited or should we just ignore you?"_.
+
+We have a growing number of enthusiasts using SimpleX Chat who can accept the security risks of unaudited system, but the users who depend on their security were patiently waiting until some independent experts review our codebase.
+
+[Trail of Bits](https://www.trailofbits.com/about), a US based security and technology consultancy whose clients include big tech companies, governmental agencies and major blockchain projects, had 2 engineers reviewing SimpleX Chat for one calendar week, specifically [simplexmq library](https://github.com/simplex-chat/simplexmq) that is responsible for all cryptography and networking of SimpleX platform.
+
+2 medium and 2 low severity issues were identified, all of which require a high difficulty attack to exploit – the attacker would need to have a privileged access to the system, may need to know complex technical details, or must discover other weaknesses to exploit them. 3 of these issues are already fixed in v4.2.
+
+In the course of the audit, Trail of Bits assessed the maturity of the [simplexmq library](https://github.com/simplex-chat/simplexmq) across eight categories and found five of them to be strong or satisfactory.
+
+Explained below is our understanding of the issues, as well as fixes implemented by the SimpleX Chat team after project completion. The full security review is available via [Trail of Bits publications](https://github.com/trailofbits/publications/blob/master/reviews/SimpleXChat.pdf).
+
+We are hugely thankful to Trail of Bits and their engineers for the work they did, helping us identify these issues and supporting the ongoing efforts to make SimpleX Chat more secure.
+
+### Medium severity issues
+
+#### X3DH key exchange for double ratchet protocol
+
+We made a mistake implementing X3DH key exchange - the key derivation function was not applied to the result of concatenation of three DH operations. The attack to exploit this mistake has high difficulty, as it would require compromising one of private keys generated by the clients, and also it would only affect forward secrecy until break-in recovery happens (after both sides sent some messages).
+
+Please note that SimpleX does not perform X3DH with long-term identity keys, as the SimpleX protocol does not rely on long-term keys to identify client devices. Therefore, the impact of compromising a key will be less severe, as it will affect only the secrets of the connection where the key was compromised.
+
+This issue is fixed in version 4.2 in [this PR](https://github.com/simplex-chat/simplexmq/pull/548/files), and if both clients are updated the key exchange will not have this vulnerability. Also, previously created connections should be secure as long as both sides sent the messages, but if you believe that your private key(s) could have been compromised (for example, if you used SimpleX Chat since before we added database encryption), we recommend that you create the new connections with your contacts, at least with the security-critical ones. Simply rotating the connection queue (manual queue rotation is added in version 4.2) will not be sufficient, as this rotation does not re-initialize the ratchets - this is something we will be adding in the future.
+
+#### Keys are stored in unpinned memory and not cleared after their lifetime
+
+The problem here is that the memory with cryptographic keys can be swapped to the storage and potentially accessed by an attacker who has root-level access to the device (or the level of access required to access swap file of the application). So, if you are running SimpleX Chat on desktop you could improve its security by running it in an isolated container.
+
+In our opinion, on mobile operating systems it is less severe as each application already runs in its own container, and applications do not share access to their swap areas (e.g., on Android swap is a [compressed area in RAM](https://developer.android.com/topic/performance/memory-management) not accessible to other applications).
+
+To exploit this issue an attacker needs to have a privileged system access to the device. Also, we believe [Haskell generational garbage collection](https://www.microsoft.com/en-us/research/wp-content/uploads/1993/01/gen-gc-for-haskell.pdf) makes the lifetime of unused memory lower than in other languages.
+
+We will be addressing this issue in the near future, possibly by using library [secure-memory](https://hackage.haskell.org/package/secure-memory-0.0.0.2) created by Kirill Elagin, an engineer at Serokell, or some other similar approach.
+
+### Low severity issues
+
+#### The string padding function is incorrect for long messages, and the string unpadding function throws exception for short messages
+
+Both these issues are fixed in 4.2 in [this PR](https://github.com/simplex-chat/simplexmq/pull/547/files), with the additional unit tests, and we also validated that even before the fix the strings that would cause such exception were never passed to this function – The SimpleX Chat team could not find the possibility of the attack that would succeed because of this issue.
+
+### What's next
+
+There are areas of SimpleX Chat that were out of scope of this review, specifically:
+
+- the chat protocol implementation and mobile UIs, as they includes no cryptography of networking (with the exception of Android app storing encrypted database passphrase and key exchange/encryption for WebRTC calls).
+- push notifications server that is used by iOS clients.
+
+We will be arranging to review these areas separately.
+
+## The new website
+
+Our [previous website](https://old-website.simplex.chat) was created 2 years ago to present SimpleX idea, there was no SimpleX Chat at the time - we only had a prototype implementation of SimpleX Messaging Protocol server then.
+
+A lot of people told us that our website didn't explain well enough who SimpleX Chat is for, what problems it solves, and how it is different from the alternatives. So, while we love to be focused on the chat application, we decided to make the new one.
+
+We hope that our [new website](https://simplex.chat) better answers these questions. If you think something should be added/removed/changed - please let us know. Thank you!
+
+## SimpleX Chat v4.2 released!
+
+New in this release:
+
+- fixed 3 issues from the security audit!
+- group links - group admins can create the links for new members to join
+- auto-accept contact requests + configure whether to accept incognito and welcome message
+- small things: change group member role, mark chat as unread, send stickers and GIFs from Android keyboards.
+
+Beta features (enable Developer tools to try them):
+
+- manually switch contact or member to another address / server (it has to be supported by both clients to work)
+- receive files faster (enable it in Privacy & Security settings)
+
+### Group links
+
+<img src="./images/20221108-group1.png" width="288">    <img src="./images/20221108-group2.png" width="288">
+
+It's been requested by many users - to be able to join a group via link. Because SimpleX Chat groups are fully decentralised, and there is no server-side state, joining via these links requires the participation of the link creator who has to be online to accept the group joining request.
+
+The way it works under the hood is similar to how contact addresses work:
+
+1. Group admin or owner creates a long term address that is technically the same as a user address, but it is associated with a specific group.
+2. The user that joins the group can identify that this link belongs to some group by an additional piece of data in the link - `{"type": "group", "groupLinkId": "some random string"}`. The ID in this link does not represent a group identity, every time any user creates a new link for the same group, this ID will be different. This ID is used by the joining client to identify the group and automatically accept the invitation when it is received.
+3. When admin receives a connection request, they automatically accept it and send invitation link to join the group.
+4. The joining user compares the ID in the invitation with the ID in the link, and if they match – automatically accepts the invitation.
+
+After that it works as when joining via the manual invitation - the joining user will be establishing the connection with all existing members to be able to send messages to the group.
+
+The link can be created via the group page, as shown on the picture.
+
+We have several groups you can join to ask any questions or just to test the app:
+
+- [#SimpleX-Group](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2FWHV0YU1sYlU7NqiEHkHDB6gxO1ofTync%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEAWbebOqVYuBXaiqHcXYjEHCpYi6VzDlu6CVaijDTmsQU%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22mL-7Divb94GGmGmRBef5Dg%3D%3D%22%7D): a general group with more than a 100 members where you can ask any questions.
+
+- Several groups by countries/languages: [\#SimpleX-DE](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fhpq7_4gGJiilmz5Rf-CswuU5kZGkm_zOIooSw6yALRg%3D%40smp5.simplex.im%2FmIorjTDPG24jdLKXwutS6o9hdQQRZwfQ%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA9N0BZaECrAw3we3S1Wq4QO7NERBuPt9447immrB50wo%253D%26srv%3Djjbyvoemxysm7qxap7m5d5m35jzv5qq6gnlv7s4rsn7tdwwmuqciwpid.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22S8aISlOgkTMytSox9gAM2Q%3D%3D%22%7D) (German), [\#SimpleX-US](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2FlTWmQplLEaoJyHnEL1-B3f2PtDsikcTs%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA-hMBlsQjNxK2vaVhqW_UyAVtuoYqgYTigK4B9dJ9CGc%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22G0UtRHIn0TmPoo08h_cbTA%3D%3D%22%7D) (US/English), [\#SimpleX-France](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2F11r6XyjwVMj0WDIUMbmNDXO996M_EN_1%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEAXDmc2Lrj9WQOjEcWa0DeQHF3HcYOp9b68s8M_BJ7gEk%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22EZCeSYpeIBkaQwCcpcF00w%3D%3D%22%7D), [\#SimpleX-RU](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fhpq7_4gGJiilmz5Rf-CswuU5kZGkm_zOIooSw6yALRg%3D%40smp5.simplex.im%2FZSYM278L5WoZiApx3925EAjSXcsAVNVu%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA7RJ2wfT8zdfOLyE5OtWLEAPowj-q6F2HB0ExbATw8Gk%253D%26srv%3Djjbyvoemxysm7qxap7m5d5m35jzv5qq6gnlv7s4rsn7tdwwmuqciwpid.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22fsVoklNGptt7n-droqJYUQ%3D%3D%22%7D) (Russian), [#SimpleX-NL](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FmP0LbswSbfxoVkkxiWE2NYnBCgZ9Snvj%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEAVwZuSsw4Mf52EaBNdNI3RebsLm0jg65ZIkcmH9E5uy8%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22M9xIULUNZx51Wsa5Kdb0Sg%3D%3D%22%7D) (Netherlands/Dutch), [#SimpleX-IT](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FaZ_wjh6QAYHB-LjyGtp8bllkzoq880u-%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA-_Wulzc3j16i7t77XJ5wgwxeW8_Ea8GxetMo7K4MgjI%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22QWmXdrFzIeMd2OoEPMFkBQ%3D%3D%22%7D) (Italian).
+
+You can join these groups either by opening these links in the app or by opening them in desktop browser and scanning QR code.
+
+Let me know if you'd like to add some other countries to the list. Join via the apps to share what's going on and ask any questions!
+
+### Auto-accept contact requests
+
+<img src="./images/20221108-address1.png" width="288">    <img src="./images/20221108-address2.png" width="288">
+
+When somebody connects to you via your long-term address you have to manually accept a connection request (it shows in blue color in the list of chats). The feature that we added in this release allows to configure the app to accept contact requests automatically, and also choose whether this contact should receive your main profile or a random incognito profile (independent of the current app setting), and add an optional auto-reply message.
+
+This feature is useful if you publish your address on your webpage or social profile, and do not want to screen people who want to connect to you. You may want to send a standard welcome message, for example, if it is an online store, and you need to share any information with everybody who contacts you.
+
+Our @simplex account that you connect to when you choose "Connect to developers" in the app used this feature for a long time, and now it is available to mobile app users.
+
+### Some small things
+
+1. Changing group member role is a very basic feature, but it was only added in this release.
+
+2. You can now mark a conversation as unread, for example if you accidentally marked all messages as read and you want to review it later.
+
+3. Send stickers and GIFs from Android keyboards, and, finally, the bug with backspace button is resolved as well.
+
+### Change your delivery address (BETA)
+
+<img src="./images/20221108-switch-address.png" width="288">
+
+To manually switch any of your contacts (or a group member to a new server address) enable Developer tools and choose "Change receiving address" on the contact page. As long as they run a new version of the app and online, the switch should only take a few seconds.
+
+That is a major improvement of metadata privacy of SimpleX protocols, because previously, while we didn't have user identifiers, the pairwise identifiers of messaging queues used to deliver messages were used for as long as the contact existed. Now these identifiers are temporary, and in a near future we will be adding automatic rotation of these delivery addresses.
+
+It is also useful when you want to migrate message delivery to another server, for example, if you used SimpleX Chat default servers and now want to self-host your own. Or, maybe, you need to change the address of your server. Previously it would require creating new contacts and losing conversation histories, and now all you have to do is to change server configuration in the app, and when the change of the address is triggered (currently, only manually, and in the near future - automatically), your contacts will be migrated to a new server, without you doing anything - it only requires each party sending 2 messages to negotiate the reconnection, and it would also rotate the encryption keys used for the outer layer of E2E encryption.
+
+### Receive images and small files faster (BETA)
+
+<img src="./images/20221108-faster-images.png" width="288">
+
+From version 4.2 all files smaller than ~92kb (equal to 6 message blocks) will be sent in the same connection where you have the chat, and files smaller than ~231kb (the limit for image size) can also be optionally received via the same connection – the latter requires enabling "Transfer images faster" in Privacy & security settings (it will be available after you enable Developer tools). There are two reasons why it is not on by default yet: 1) we wanted to ensure it is stable; 2) there is a small effect on metadata privacy of having a burst of traffic in the same connection where you are having the main conversation.
+
+This functionality was created for the future voice messages, as they need to be sent without acceptance, so that the recipients can listen to them even when the sender is offline.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md#privacy-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see the information on our [new website](https://simplex.chat) - it also answers all these questions.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat) - it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat) - it charges a commission, and also accepts donations in many crypto-currencies.
+- Monero wallet: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+- Bitcoin wallet: bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u
+- please let us know, via GitHub issue or chat, if you want to make a donation in some other cryptocurrency - we will add the address to the list.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20221206-simplex-chat-v4.3-voice-messages.html b/blog/20221206-simplex-chat-v4.3-voice-messages.html
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     <meta name="twitter:card" content="summary" />
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+    
+<link rel="alternate" type="text/markdown" href="/blog/20221206-simplex-chat-v4.3-voice-messages.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
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diff --git a/blog/20221206-simplex-chat-v4.3-voice-messages.md b/blog/20221206-simplex-chat-v4.3-voice-messages.md
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+# SimpleX Chat reviews and v4.3 released – with instant voice messages, irreversible deletion of sent messages and improved server configuration.
+
+**Published:** Dec 6, 2022
+
+## SimpleX Chat reviews
+
+Since we published [the security assessment of SimpleX Chat](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md) completed by Trail of Bits in November, several sites published the reviews and included it in their recommendations:
+
+- Privacy Guides added SimpleX Chat to [the recommended private and secure messengers](https://www.privacyguides.org/real-time-communication/#simplex-chat).
+- Mike Kuketz – a well-known security expert – published [the review of SimpleX Chat](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) and added it to [the messenger matrix](https://www.messenger-matrix.de).
+- Supernova published [the review](https://supernovas.space/detailed_reviews.html#simplex) and increased [SimpleX Chat recommendation ratings](https://supernovas.space/messengers.html).
+
+## What's new in v4.3
+
+- [instant voice messages!](#instant-voice-messages)
+- [irreversible deletion of sent messages for all recipients](#irreversible-message-deletion)
+- [improved SMP server configuration and support for server passwords](#smp-servers-configuration-and-password)
+- [privacy and security improvements](#privacy-and-security-improvements):
+  - protect app screen in recent apps and prevent screenshots
+  - improved privacy and security of SimpleX invitation links in the app
+  - optional Android app data backup
+  - optionally allow direct messages between group members
+
+### Instant voice messages
+
+<img src="./images/20221206-voice.png" width="288">
+
+Voice messages, unlike normal files, are sent instantly, in the existing connection with your contact and without acceptance from the recipient. For this reason we limited the size of voice messages to ~92.5kb (an equivalent of 6 messages), that limits the duration to 30 seconds on iOS and to ~42 seconds on Android (the size is different because of different encoders), with an average sound quality. The voice messages are sent in MP4AAC format that is natively supported both on iOS and on Android, and you can play voice message files outside of SimpleX Chat app.
+
+Users who do not want to receive voice messages can disable them, either globally, for all contacts, or for each contact independently. Please note that the global preference change will only affect the contacts where you shared your main profile (not incognito contacts) and where you didn't change the preference for the particular contact. Groups have a separate policy that allows disabling voice messages for all members (they are allowed by default). The owner can set this policy when creating a group or later, via Group preferences page.
+
+### Irreversible message deletion
+
+<img src="./images/20221206-deleted1.png" width="288">    <img src="./images/20221206-deleted2.png" width="288">
+
+When you receive email, you have full confidence that the sender cannot delete their email from your mailbox after you received it. And it seems correct – in the end, this is your device, and nobody should be able to delete any data from it.
+
+Most existing messengers made an opposite decision – the senders can irreversibly delete their messages from the recipients' devices after they were delivered, whether recipients agree to that or not. And it seems correct too - this is your message, you should be able to delete it, at least for a limited time; that the message is on the recipient device doesn't change your ownership of this message.
+
+While both these statements appear correct, at least to some people, they simply cannot both be correct at the same time, as they contradict each other - either one or both of them must be wrong. This appears to be a very polarising subject, and [the polls](https://mastodon.social/@simplex/109461879089268041) [I made](https://www.reddit.com/r/SimpleXChat/comments/zdam11/poll_irreversible_message_deletion_by_sender_what/) [yesterday](https://twitter.com/epoberezkin/status/1599797374389727233) [show it](https://www.linkedin.com/feed/update/urn:li:activity:7005564342502842368/) - the votes are split evenly.
+
+You may want to be able to delete your messages even after they are received to protect your privacy and security, and you want the communication product you use to enforce it. But you may also have many reason to disagree to the deletion of messages on your device for several different reasons:
+
+- it may be a business context, and either your organisation policy or a compliance requirement is that every message you receive must be preserved for some time.
+- these messages may contain threat or abuse and you want to keep them as a proof.
+- you may have paid for the the message (e.g., it can be a consulting report), and you don't want it to suddenly disappear before you had a chance to store it outside of the conversation.
+
+Instead of taking any side in this choice, we decided to allow to change this behaviour either globally or separately for each contact or group. That makes SimpleX Chat unique, being suitable both for the communication contexts where email is traditionally used and in informal or privacy sensitive contexts, that would allow the senders to delete messages irreversibly, provided that the recipients agree to that.
+
+In any case, the senders can never be 100% certain that the message is deleted from the recipient's device - recipient can be running a modified client that does not honour the conversation setting, and there is no way to ascertain which code your contact runs on their device.
+
+If irreversible message deletion is not allowed in the conversation, the senders can still mark their messages as deleted, and it would show "mark deleted" placeholder in the conversation. The recipients can then both reveal the content of the original message and fully delete it on their devices.
+
+### SMP servers configuration and password
+
+<img src="./images/20221206-server1.png" width="288">    <img src="./images/20221206-server2.png" width="288">    <img src="./images/20221206-server3.png" width="288">
+
+When you self-host your own SMP server you may want to make it public so that anybody can use it to receive messages. But many users want to host their private servers, so that only they and their friends can use them to receive the messages.
+
+v4.0 of SMP server and the new version of the apps adds support for server passwords. It is chosen randomly when you initialize the new server, and if you already have a server you can change it. Anybody can still message you, it doesn't require knowing the password, and the links you share do not include it, but to be able to receive the messages you need to know a server address that includes the password. In a way, it is similar to how basic authentication works in HTTP, and how browsers support the URIs with included credentials.
+
+The new server configuration section now allows to test your servers before you start using them, and you can also share your server address via QR code, so that your friends or your team can use them too, without the need to copy paste the addresses.
+
+You can read how to install and configure SMP servers in [this guide](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SERVER.md).
+
+### Privacy and security improvements
+
+#### Protect app screen
+
+<img src="./images/20221206-protect.png" width="330">
+
+It is now enabled by default, but you can disable it via settings.
+
+iOS app only hides the app screen in the recent apps, Android app in addition to that also prevents the screenshots.
+
+This is not the security measure for the senders, and we made it optional, as the recipient could circumvent it anyway – this is for you to protect your app screen when you give your phone to somebody.
+
+#### Privacy and security of SimpleX invitation links
+
+Previously, when you sent somebody an invitation link, a contact address or a group link, they would take half a screen in the chat and they could open in the browser in some cases. Also, as these links are quire large, it is not easy to see if the page domain is maliciously replaced, what SMP server the connection would go through or what kind of link it is.
+
+This version instead of showing the full link shows a short description, and it replaces a public web address with an internal URI scheme that the app uses (simplex:/) – such links open directly in the app. There is an option to show the full link, if you need it, and even to open it in the browser from the app, but in this case if this link is not using https://simplex.chat website it will show as red to highlight it.
+
+### Optional Android app data backup
+
+The previous version always backed up app data in the way it was configured by the system. Now you can override it from inside the app, preventing the backup even if it's enabled by the system settings. This version requires disabling it manually, we will make it disabled by default in the next release (v4.3.1).
+
+### Direct messages between group members
+
+The new version does not allow them by default, but it can be enabled by group owners in the group settings when the group is created or at any later moment.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.md#privacy-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see the information on our [new website](https://simplex.chat) - it also answers all these questions.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat) - it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat) - it charges a commission, and also accepts donations in many crypto-currencies.
+- Monero address: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+- Bitcoin address: bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u
+- Ethereum address: 0xD7047Fe3Eecb2f2FF78d839dD927Be27Bc12c86a (donate.simplexchat.eth)
+- please let us know, via GitHub issue or chat, if you want to make a donation in some other cryptocurrency - we will add the address to the list.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230103-simplex-chat-v4.4-disappearing-messages.html b/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
index 1d96eb0c66..e9b71e9f1f 100644
--- a/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
+++ b/blog/20230103-simplex-chat-v4.4-disappearing-messages.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230103-simplex-chat-v4.4-disappearing-messages.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230103-simplex-chat-v4.4-disappearing-messages.md b/blog/20230103-simplex-chat-v4.4-disappearing-messages.md
new file mode 100644
index 0000000000..86f0bc75ea
--- /dev/null
+++ b/blog/20230103-simplex-chat-v4.4-disappearing-messages.md
@@ -0,0 +1,94 @@
+# SimpleX Chat v4.4 released – with disappearing messages, live messages, connection security verification and French language!
+
+**Published:** Jan 3, 2023
+
+## What's new in v4.4
+
+- [disappearing messages](#disappearing-messages).
+- ["live" messages](#live-messages).
+- [connection security verification](#connection-security-verification).
+- [animated images and stickers](#animated-images-and-stickers) – now on iOS too.
+
+Also, we added [French language interface](#french-language-interface), thanks to the users' community and Weblate!
+
+### Disappearing messages
+
+<img src="./images/20230103-disappearing1.png" width="288">    <img src="./images/20230103-disappearing2.png" width="288">
+
+It is now possible to send the messages that will be deleted from both sender and recipient device after set time – for the sender from the time they were sent, and for the recipient - from the time they were read.
+
+Unlike in most other messengers, it requires agreement of both sides, not just the sender decision. I [wrote previously](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#irreversible-message-deletion) why we believe it is wrong to allow the senders to delete their messages without recipient consent, and the same logic applies here – if you want to send the message that will disappear after some time, your contact should be ok with that too.
+
+In group conversations disappearing messages can be enabled by the group owners, by default they are disabled.
+
+### "Live" messages
+
+<img src="./images/20230103-live.png" width="288">
+
+Pressing "bolt" button before you start typing the message will start a "live" message. Now, as you type it, it will be updated for all recipients every several seconds, including only complete words. To finish the message you need to press "checkmark" button.
+
+You can also start a live message after you started typing or after you chose the image – long-press send button and then press "Send live message".
+
+### Connection security verification
+
+<img src="./images/20230103-verification.png" width="288">
+
+SimpleX Chat design prevents the possibility of messaging servers substituting the key during the initial connection (man-in-the-middle attack) by requiring that the invitation link is passed via another channel. I wrote more about how MITM attack works in [this post](https://www.poberezkin.com/posts/2022-12-07-why-privacy-needs-to-be-redefined.html). But this other channel, however unlikely, could still have been compromised by an attacker to replace the invitation link you sent. That is the reason why we recommend sharing QR code in a video call – this is very complex for an attacker to replace it in this case.
+
+This new feature allows you to verify, via yet another channel, that the connection is secure and the keys were not replaced. You can either scan the security code from your contact's app, or compare codes visually, or even read it in a voice call – if your and your contact's app have the same security code for each other then the connection is secure.
+
+If you are sending direct messages to some group members then it might also be important to verify security of these connections, as in this case the invitations were exchanged via the member who added you or another member, and if this member's client was modified, they could have replaced the keys and the addresses, and intercept the entire conversation.
+
+Regardless how connection is established, verifying the connection proves its security. Technically, this security code is the hash of associated data used in the end-to-end encryption, which in turn is taken by combining public keys from the initial key exchange.
+
+### Animated images and stickers
+
+<img src="./images/20230103-stickers1.png" width="288">    <img src="./images/20230103-stickers2.png" width="303">
+
+Android app supported GIFs and stickers for some time, now you can view and send them from iOS app as well, e.g. using GIPHY keyboard - you no longer need to choose between privacy and stickers. Just bear in mind, that third party keyboards can be insecure, so you should not be using them for typing sensitive information.
+
+### French language interface
+
+Thanks to our users' community and to [Weblate](https://weblate.org/en-gb/) kindly providing a free hosting plan for SimpleX Chat translations we can now support more languages in the interface – this version adds French.
+
+Please get in touch if you want to translate the interface into your language!
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+It is possible to donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat) - it is commission-free for us.
+- [OpenCollective](https://opencollective.com/simplex-chat) - it charges a commission, and also accepts donations in crypto-currencies.
+- Monero address: 8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c
+- Bitcoin address: bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u
+- BCH address: bitcoincash:qq6c8vfvxqrk6rhdysgvkhqc24sggkfsx5nqvdlqcg
+- Ethereum address: 0xD7047Fe3Eecb2f2FF78d839dD927Be27Bc12c86a (donate.simplexchat.eth)
+- please let us know, via GitHub issue or chat, if you want to create a donation in some other cryptocurrency - we will add the address to the list.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
index 6a3f06d262..26f7e349b1 100644
--- a/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
+++ b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md
new file mode 100644
index 0000000000..23c6f36c88
--- /dev/null
+++ b/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md
@@ -0,0 +1,112 @@
+# SimpleX Chat v4.5 released – with multiple user profiles, message draft, transport isolation and Italian interface!
+
+**Published:** Feb 4, 2023
+
+## What's new in v4.5
+
+- [multiple chat profiles](#multiple-chat-profiles).
+- [message draft](#message-draft).
+- [transport isolation](#transport-isolation).
+- [reduced battery usage](#reduced-battery-usage).
+- [private filenames](#private-filenames).
+
+Also, we added [Italian interface](#italian-interface), thanks to the users' community and Weblate!
+
+### Multiple chat profiles
+
+<img src="./images/20230204-profiles1.png" width="288">    <img src="./images/20230204-profiles2.png" width="288">
+
+Incognito mode added in v3.2 allows to share a random profile name with your new contacts. It is quite popular - more than half of users connecting to our support profile use it. In case when you just want a throw-away profile name that doesn't share any information about you it is more convenient that creating a new profile for each contact manually.
+
+But there are many cases when a disposable profile is not good enough enough, and you want to create separate profiles - one for your family, another for work, yet one more for your online contacts that only know your pseudonym rather than your real name.
+
+Previously this was only possible by using separate chat databases. This version adds a chat profile manager that allows you to create unlimited number of profiles, and very quickly switch them. All these profiles are connected at the same time.
+
+When you delete profile you no longer need you have two options - either delete both profile data on the device and any message queues that this profile created on SMP servers (e.g., when it is more important to leave as few meta-data on the servers), or delete only profile data without making any network requests (when it is more important to delete all data from the device quickly).
+
+While most app settings apply to all profiles, several settings are profile-specific.
+
+You can separately set which SMP servers are used to create the new contacts in each profile (via Network settings). Please note: changing SMP servers in one profile won't affect other profiles, and all new profiles are created with preset servers.
+
+You can also separately set the retention time for messages in each profile (via Database settings).
+
+Also, you have a different contact address in each profile, and different Chat preferences.
+
+All other settings are used for all profiles. While you may want to have different settings for different security levels, it is much better to use different devices in this case.
+
+### Message draft
+
+<img src="./images/20230204-draft1.png" width="288">    <img src="./images/20230204-draft2.png" width="288">
+
+Previously, if you've closed the conversation with unsent message, this message was disappearing. While it might be better for privacy, there are several scenarios when it is very inconvenient:
+
+- you need to compose the message from several parts that you copy from other conversations.
+- some messages arrives that you need to answer urgently, so you can leave unfinished message to return to it later.
+
+Both are now possible - the message you wrote, together with any attachments, and even a voice message you recorded, will remain available as draft until you either close the app or leave another message unfinished - while you can send the message in another chat without losing the current draft, there can be only one draft at a time.
+
+### Transport isolation
+
+<img src="./images/20230204-transport.png" width="288">
+
+Even when you create different chat profiles you are still connecting to your contacts via the same device. Transport isolation, by default, makes connections belonging to the same profile use different TCP sessions, so while the server sees the same IP address, it doesn't see it as the same client connection. If you are connecting via Tor using SOCKS proxy (e.g. Orbot app on Android) not only the app will use different TCP sessions, it will also use separate Tor circuits for connections from different profiles, preventing the servers and network observers seeing this as traffic coming from the same device.
+
+There is an additional BETA option to use a separate transport connection for each contact and group member connection you have – it is available in Network settings if you enable dev tools. In case you have a large number of contacts or participate in large groups across all profiles in the app, you should not use this option, as it may create a lot of traffic and also can exceed the quota for TCP sockets. Also creating a lot of separate Tor circuits can be slow. We will be testing at which number of connections this option starts failing and by the time it's available without dev tools we will add some limits.
+
+### Reduced battery usage
+
+Battery usage is one of the biggest complaints of SimpleX Chat users. The main reason for excess traffic is inefficient retry strategies for Network operations in these cases:
+
+- the message queue capacity is exceeded - the app will keep retrying to send the message until there will be capacity.
+- the server is not available, e.g. if you connect to somebody via their server, and they later disable it. This case creates much less extra traffic than the first.
+
+This version makes retries for exceeded queue capacity 10x less frequent and adds SMP protocol extension that will allow to reduce retries even further by the next version. It works in the following way:
+- when the sender encounters "queue quota exceeded" error, the sender stops trying to send the message.
+- the server also takes note of that error.
+- once recipient receives all messages from this queue, the server will notify the recipient that the sender had "queue quota exceeded" error.
+- the recipient will then send a special message to the sender client to instruct it that it can resume delivery.
+- the sender can still occasionally try sending the message, e.g. once every hours, but it won't need to retry once every few minutes as it does now.
+
+Reducing battery usage is our big priority - we expect to reduce it by at least 2-3x in the next few months.
+
+### Private filenames
+
+When you send an image or voice message they are sent as files with filenames including timestamp. We didn't see it as a problem, as files are sent together with the message, and messages have server-side timestamps anyway. But the users pointed out that the timestamp we used was in the local timezone, and therefore leaked the country (or continent) where the user is located. A simple workaround was to reset timezone to UTC, and that is what most users who need to protect their location do anyway. But this version resolves it - these filenames now include UTC timezones – no workarounds are needed.
+
+### Italian interface
+
+Thanks to our users' community and to Weblate providing a free hosting plan for SimpleX Chat translations we can now support more languages in the interface – this version adds Italian and many more is in progress - Chinese, Japanese, Czech, Dutch, etc.
+
+You can [contribute the translation](https://github.com/simplex-chat/simplex-chat/tree/stable#translate-the-apps) of the apps to your language too!
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230301-simplex-file-transfer-protocol.html b/blog/20230301-simplex-file-transfer-protocol.html
index ae0e76bd7c..d91c34867c 100644
--- a/blog/20230301-simplex-file-transfer-protocol.html
+++ b/blog/20230301-simplex-file-transfer-protocol.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230301-simplex-file-transfer-protocol.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230301-simplex-file-transfer-protocol.md b/blog/20230301-simplex-file-transfer-protocol.md
new file mode 100644
index 0000000000..d8fc9fd49b
--- /dev/null
+++ b/blog/20230301-simplex-file-transfer-protocol.md
@@ -0,0 +1,154 @@
+# SimpleX File Transfer Protocol – a new protocol for sending large files efficiently, privately and securely.
+
+**Published:** Mar 1, 2023
+
+- [Quick start: how to send a file using XFTP CLI](#⚡️-quick-start-send-a-file-with-xftp-cli-in-3-simple-steps)
+- [What's the problem](#whats-the-problem)
+- [Why didn't we just use some existing solution?](#why-didnt-we-just-use-some-existing-solution)
+- [What is XFTP and how does it work?](#what-is-xftp-and-how-does-it-work)
+- [What is next?](#what-is-next)
+
+## ⚡️ Quick start: send a file with XFTP CLI in 3 simple steps
+
+Download XFTP binary for Linux from [the release](https://github.com/simplex-chat/simplexmq/releases/tag/v5.0.0-beta.3) – you need the file `xftp-ubuntu-20_04-x86-64` - rename it as `xftp`.
+
+**Step 1**: To send the file:
+
+```bash
+xftp send filename.ext
+```
+
+You can also send the file that can be received by multiple recipients using `-n` option:
+
+```bash
+xftp send filename.ext -n 10
+```
+
+**Step 2**: Pass file description(s) (files `rcvN.xftp`) to the recipient(s) securely, e.g. send it as a file via SimpleX Chat.
+
+**Step 3**: To receive the file:
+
+```bash
+xftp recv rcvN.xftp
+```
+
+The sender also delete all file chunks from the relays before they expire in 48 hours with this command:
+
+```bash
+xftp del ./filename.ext/snd.xftp.private
+```
+
+<br>
+
+## What's the problem?
+
+If you are using SimpleX Chat apps you know that support of sending files and images is not very good, and sending videos and large files is simply impossible. There are currently these problems:
+
+- the sender has to be online for file transfer to complete, once it was confirmed by the recipient.
+- when the file is sent to the group, the sender will have to transfer it separately to each member, creating a lot of traffic.
+- the file transfer is slow, as it is sent in small chunks - approximately 16kb per message.
+
+As a result, we limited the supported size of files in the app to 8mb. Even for supported files, it is quite inefficient for sending any files to large groups.
+
+## Why didn't we just use some existing solution?
+
+We really hoped to find some existing open-source solution that we could integrate with SimpleX Chat.
+
+We decided not to use torrent-like or any other P2P solutions because of their lack of privacy, challenging legality in some jurisdictions and, in many cases, because they are inefficient in groups.
+
+We reviewed several S3-compatible solutions (e.g., [minio](https://github.com/minio/minio), [garage](https://git.deuxfleurs.fr/Deuxfleurs/garage), [SeaweedFS](https://github.com/seaweedfs/seaweedfs)), but they all require the development of a separate service layer, making them unusable as standalone services and harder to deploy for the users who want to self-host the file transfer service. As a side note, the solution that we developed can still be composed with S3-compatible storage for higher capacity servers with some privacy/efficiency trade-offs.
+
+We also looked at a few independent implementations of file sharing, with some ad-hoc protocols (e.g., [ceph](https://github.com/ceph/ceph) and [lufi](https://framagit.org/fiat-tux/hat-softwares/lufi)), but neither seemed sufficiently mature, and also not as private as we would like.
+
+So after a lot of searching we decided to design and implement a new protocol for file transfers, that both solved the problems above, and provided a higher level of metadata privacy than any other file transfer solution has.
+
+## What is XFTP and how does it work?
+
+```
+           Sender                      Internet                XFTP relays             Internet         Recipient
+----------------------------   |   -----------------   |   -------------------   |   ------------   |   ---------- 
+                               |                       |                         |                  |
+                               |                       |   (can be self-hosted)  |                  |
+                               |                       |        +---------+      |                  |
+                  chunk 1     ----- HTTP2 over TLS ------       |  XFTP   |     ---- HTTP2 / TLS -----   chunk 1
+                |---> SimpleX File Transfer Protocol (XFTP) --> |  Relay  | --->        XFTP         ------------->|
+                |             ---------------------------       +---------+     ----------------------             |
+                |              |                       |                         |                  |              | 
+                |              |                       |                         |                  |              v
+          +----------+         |                       |        +---------+      |                  |        +-------------+
+          | Sending  | ch. 2  ------- HTTP2 / TLS -------       |  XFTP   |     ---- HTTP2 / TLS ----  ch. 2 |  Receiving  |
+file ---> |   XFTP   | ------>           XFTP            ---->  |  Relay  | --->        XFTP         ------> |     XFTP    | ---> file
+          |  Client  |        ---------------------------       +---------+     ----------------------       |    Client   |
+          +----------+         |                       |                         |                  |        +-------------+
+                |              |                       |                         |                  |              ^
+                |              |                       |        +---------+      |                  |              |
+                |             ------- HTTP2 / TLS -------       |  XFTP   |     ---- HTTP2 / TLS ----              |
+                |------------->           XFTP           ---->  |  Relay  | --->        XFTP         ------------->|
+                   chunk N    ---------------------------       +---------+     ---------------------    chunk N
+                               |                       |   (store file chunks)   |                  |
+                               |                       |                         |                  |
+                               |                       |                         |                  |
+```
+
+XFTP stands for SimpleX File Transfer Protocol. Its design is based on the same ideas and has some of the qualities of SimpleX Messaging Protocol, that is used in SimpleX Chat:
+
+- recipient cannot see sender's IP address, as the file fragments (chunks) are temporarily stored on multiple XFTP relays.
+- file can be sent asynchronously, without requiring the sender to be online for file to be received.
+- there is no network of peers that can observe this transfer - sender chooses which XFTP relays to use, and can self-host their own.
+- XFTP relays do not have any file metadata - they only see individual chunks, with access to each chunk authorized with anonymous credentials (using Edwards curve cryptographic signature) that are random per chunk.
+- chunks have one of the sizes allowed by the servers - currently we allow 256kb, 1mb and 4mb chunks, so if you send, say 1gb file, to XFTP relays it will look indistinguishable from sending many small files, and they would only know that chunks are sent by the same user only via the transport information, but none of the relays will see all chunks. Also, once this feature is available in mobile apps you can use transport isolation per chunk, when each file fragment will be uploaded via a separate TCP connection (and Tor circuit, if you use Tor) – the CLI we released does not yet support per-chunk transport isolation.
+- each chunk can be downloaded by multiple recipients, but each recipient uses their own key and chunk ID to authorize access, and the chunk is encrypted by a different key agreed via ephemeral DH keys (NaCl crypto_box (SalsaX20Poly1305 authenticated encryption scheme ) with shared secret derived from Curve25519 key exchange) on the way from the server to each recipient. XFTP protocol as a result has the same quality as SMP protocol - there are no identifiers and ciphertext in common between sent and received traffic inside TLS connection, so even if TLS is compromised, it complicates traffic correlation attacks.
+- XFTP protocol also supports redundancy - each file chunk can be sent via multiple relays, and the recipient can choose the one that is available. The released CLI does not support redundancy though.
+- the file as a whole is encrypted with a random symmetric key using NaCl secret_box.
+
+So, how would any recipient know where to get all these file fragments from and how to put them back together into the original file? Normally, when you send a file via any file-sharing service it provides you a link that you can pass to the recipient. The link allows to download the original file, but it also provides the server a lot of file meta-data, that often includes file name and exact size, and in many cases the server also has access to a file content.
+
+Instead of using a link, XFTP protocol includes a special format for a "file description" - it is a small text file containing the locations, access keys and digests for all file chunks, and also the encryption key and digest (SHA512) for the whole file. This file description does not contain the original file name or exact file size, so if it is used after the file fragments are expired or removed from XFTP relays, this information is not accessible.
+
+CLI generates a separate file description for each intended recipient - you need to specify how many people you want to be able to receive this file. You can specify a larger number of recipients to avoid revealing the real number of recipients from XFTP relays. Mobile apps, when this protocol is integrated, will do it automatically, choosing some large random number of possible recipients, so while the relays will be able to observe how many people time the file was downloaded, they won't know how many intended recipients you had - sending to a group of 10 people and to 1 recipient can look the same to the relays.
+
+File description is a security-sensitive file that contains private keys and chunk addresses necessary to receive the whole file, and also a symmetric key to decrypt the file. Therefore you must use a secure channel to send file description - e.g., it can be sent via SimpleX Chat. But once the recipient downloaded the file, CLI invalidates the file fragment addresses on relays and the same file description cannot be used again to download the file.
+
+## What is next?
+
+We released and deployed several XFTP relays for you to experiment with (they are hardcoded in the XFTP CLI), and you can deploy your own relays either from [downloadable binary](https://github.com/simplex-chat/simplexmq/releases/tag/v5.0.0-beta.3) or by compiling [the source code](https://github.com/simplex-chat/simplexmq). We also released XFTP CLI - it is available in the same release.
+
+We are currently integrating support for sending large files using XFTP protocol into SimpleX Chat clients. SimpleX Chat v5.0 will have support for receiving files sent via XFTP protocol (you will be able to send a file description via a SimpleX Chat CLI app, so that mobile apps will be able to receive them as normal files, only much faster), and v5.1 will fully support for sending large files (up to 1gb) in the mobile apps.
+
+We will also publish a formal specification for XFTP protocol and overview of its security qualities and threat model. For now you can learn more about the protocol design and motivations from this internal [XFTP protocol RFC](https://github.com/simplex-chat/simplexmq/blob/stable/rfcs/2022-12-26-simplex-file-transfer.md).
+
+Using and sending files with the available XFTP CLI will hugely help us stabilizing both the protocol and implementations. What we really like about this design is that it is completely independent from SimpleX Chat - you can use it on its own, sending files and passing file descriptions to your contacts via any other messenger - e.g. via Signal, – without this messenger being able to observe that you are in fact sending a large file.
+
+We did not yet decide whether we will be making a separate security audit of XFTP implementation, or if we combine it with the next security audit of SimpleX Chat. The latter seems more likely, as XFTP uses the same cryptographic primitives that were reviewed during [SimpleX Chat security assessment by Trail of Bits](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md) in November 2022.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230328-simplex-chat-v4-6-hidden-profiles.html b/blog/20230328-simplex-chat-v4-6-hidden-profiles.html
index 6598e73aaf..604b8d060e 100644
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230328-simplex-chat-v4-6-hidden-profiles.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230328-simplex-chat-v4-6-hidden-profiles.md b/blog/20230328-simplex-chat-v4-6-hidden-profiles.md
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@@ -0,0 +1,119 @@
+# SimpleX Chat v4.6 – with hidden profiles, community moderation, improved audio/video calls and reduced battery usage.
+
+**Published:** Mar 28, 2023
+
+## What's new in v4.6
+
+- [ARMv7a and Android 8+ support](#armv7a-32-bit-and-android-8-support)
+- [hidden chat profiles](#hidden-chat-profiles)
+- [group / community moderation](#group--community-moderation)
+- [group welcome message](#group-welcome-message)
+- [improved audio/video calls](#improved-audiovideo-calls)
+- [reduced battery usage](#reduced-battery-usage).
+- [SMP server monitoring: status bot and page](#smp-server-monitoring)
+
+Also, we added [Chinese and Spanish interface languages](#chinese-and-spanish-interface---you-can-choose-the-language-via-the-app), thanks to the users' community and Weblate!
+
+### ARMv7a (32 bit) and Android 8+ support!
+
+It increases the number of supported Android devices twice - now most of your friends should be able to install SimpleX Chat. SimpleX Chat still doesn't support Android 7 and erlier versions.
+
+If you install the app from GitHub or F-Droid you need to choose the correct APK, Play Store will provide it automatically.
+
+### Hidden chat profiles
+
+<img src="./images/20230328-hidden-profiles1.png" width="288">    <img src="./images/20230328-hidden-profiles2.png" width="288">    <img src="./images/20230328-hidden-profiles3.png" width="288">
+
+For a long time the main way to protect SimpleX Chat app from people who have access to your phone was device authentication - it is requested when you open the app (and some of its sensitive functions).
+
+Many users asked to allow setting the app password or PIN independently from the device PIN, as some other apps do. But it did not seem a good enough solution - if somebody has your device PIN, then in most cases they can also ask you to provide the app PIN as well.
+
+So instead of having an app password, that reduces convenience and doesn't improve security too much, we did what we think could be better. You can now create hidden chat profiles, that are not visible anywhere in the app, and do not show any notifications, until you enter a correct passphrase. If multiple profiles are hidden with the same passphrase they will all show in the list when you enter it.
+
+It's important to remember that these hidden profiles are still stored locally on your device, so if somebody has access to your chat database (they need to know database passphrase, that is independent from device PIN or profile passphrases) or to chat console in the app, they will be able to access these profiles data and reset their passwords. We are considering how chat console can be better protected - e.g., by requiring a separate password or by providing an option to remove it from the UI permanently - tell us what you think.
+
+### Group / Community moderation
+
+Initially we did not design SimpleX Chat to support communities - our focus has always been maximum privacy and security.
+
+SimpleX Chat supports small and fully decentralized groups, that are not hosted anywhere. But many users want to participate in and to discover communities. Since we added support for group links, the groups we created to let users test the app started to grow, and many other communities of over 100 people emerged.
+
+We are already observing some less-than-friendly messages and undesirable content that is not welcome in some communities. So this version adds features allowing to moderate groups.
+
+Firstly, group admins and owners can revoke members rights to send messages to the group by assigning members an "observer" role, and also make this role default for users joining via a group link.
+
+Secondly, group admins can now delete messages sent by other members (excluding the messages sent by the group owners). "Moderate" action in the message menu will either mark the message as deleted or delete it irreversibly for all members, as set in group preferences by the owners.
+
+These features will allow group owners to decide their own rules. More robust moderation tools are coming later when we build support for large communities.
+
+### Group welcome message
+
+Group owners can now set a welcome message that will be shown to new members when they join the group via a group link.
+
+### Improved audio/video calls
+
+<img src="./images/20230328-call2.png" width="288">
+
+Prior to this version audio and video calls in iOS app were very limited – they only worked while the app was in foreground. This version fully re-implemented audio/video calls in iOS – it now uses native WebRTC library instead of web view. These calls are still end-to-end encrypted, and compatible with the calls in the previous versions of the app, both on iOS and on Android platforms.
+
+Where allowed by App Store policy, the calls on iOS now use Apple's native interface for calls CallKit, that allows to accept calls from the lock screen, prevents call interruption by incoming phone calls and optionally allows to include calls in the phone call history - the last option needs to be enabled separately.
+
+Calls on Android were also improved – they now support bluetooth headphones, allow changing volume in video calls and support proximity sensor during the audio call, to prevent accidental interruption when you hold the phone close to your ear.
+
+### Reduced battery usage
+
+We know that battery usage of SimpleX Chat is suboptimal, and we are committed to reduce it. Unfortunately, there is no simple change that we could make to solve this problem, it requires many systematic improvements and fixes.
+
+One of the big issues, particularly in large groups, was inefficient retry strategy for sending messages in cases when the receiving message queue (mailbox) was out of capacity.
+
+This version increases the maximum retry period for "out-of-capacity" scenario to 1 hour, and also preserves this retry period in the database. So, if previously before the message expired in 48 hours there were up to ~2800 delivery attempts and up to ~45Mb wasted traffic per recipient (depending on how frequently the app was restarted), now there will be only ~50 retries, resulting in not more than 0.8Mb of traffic - up to 56x traffic reduction when sending messages to the large groups.
+
+This issue might not have affected you at all, and also solving it won't reduce overall traffic/battery usage by that factor - there are other inefficiences we will be addressing. But if you actively sent messages to large groups you should observe a substantial reduction of battery and traffic consumption.
+
+Please share your experience. If the battery usage is still suboptimal, please share your usage statistics - they can be requested in chat console with `/get stats` command - it will return the aggregated number of network operations, per server, since the app was started. Please note that these statistics include the addresses of the servers you connect to, so if you want to keep them private, please redact them. You can also reset usage statistics with `/reset stats` command.
+
+### SMP server monitoring
+
+If you use preset servers in SimpleX Chat you can now see when we do any maintenance or when the server is down either by [connecting to status bot via the app](https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2FShQuD-rPokbDvkyotKx5NwM8P3oUXHxA%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA6fSx1k9zrOmF0BJpCaTarZvnZpMTAVQhd3RkDQ35KT0%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion) or by visiting a [status page](https://status.simplex.chat). Status bot always sends automatic messages before the server is restarted for maintenance, but in case of downtime if the same server is down that you use to receive the messages from the bot, you may miss them - check the status page in this case.
+
+### Chinese and Spanish interface - you can choose the language via the app!
+
+Thanks to our users' community and to Weblate providing a free hosting plan for SimpleX Chat translations we can now support more languages in the interface – this version adds Chinese and Spanish and more are in progress.
+
+You can [contribute the translation](https://github.com/simplex-chat/simplex-chat/tree/stable#translate-the-apps) of the apps to your language too!
+
+The app now supports 8 languages in addition to English - Czech, German, Spanish, French, Italian, Dutch, Russian and Chinese. You can now choose the language via the app settings (Appearance page), independently from the system settings.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[SimpleX Chat security assessment](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/#how-simplex-works).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/#why-ids-bad-for-privacy).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Visit our [website](https://simplex.chat) to learn more.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
index 781e62a817..bd6ab400c6 100644
--- a/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
+++ b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md
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+++ b/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md
@@ -0,0 +1,123 @@
+# SimpleX Chat: vision and funding, v5.0 released with videos and files up to 1gb.
+
+**Published:** Apr 22, 2023
+
+SimpleX Chat vision and funding:
+- [why is it a commercial company?](#why-is-it-a-commercial-company)
+- [how is it funded and what is the business model?](#how-is-it-funded-and-what-is-the-business-model)
+- [what is next?](#what-is-next)
+
+What's new in v5.0:
+- [send videos and files up to 1gb](#send-videos-and-files-up-to-1gb)
+- [app passcode independent from system authentication](#app-passcode)
+- [networking improvements](#networking-improvements)
+
+Also, we added Polish interface language, thanks to [the users' community and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+SimpleX Chat apps are now available in 10 languages!
+
+## SimpleX Chat vision and funding
+
+### Why is it a commercial company?
+
+It was a big decision: whether SimpleX Chat should be a non-profit project or an open-source project led by a commercial company.
+
+During the last 25 years of the Internet, commercial companies have shown a much higher ability to innovate than non-profit organizations. One of the most inspiring examples is NetScape that created the Web as we know it - not only as the destination to access information, but also as an application platform, inventing cookies, SSL and JavaScript, that to this day remain the main building blocks for all web applications.
+
+While SimpleX Chat Ltd is a commercial company, SimpleX Chat software is and will remain open-source. We believe that this way we will create much more value both for the end users, and also for the shareholders and the employees of the company.
+
+Many large tech companies prioritizing value extraction over value creation earned a bad reputation for all businesses, particularly in the communities that value decentralization and privacy. But commercial objectives do not have to result in exploitation. Our goal is to build a new kind of communication network, and also an application platform, that is private by design, fully decentralized and not owned by any single entity, where SimpleX Chat Ltd is one of many organizations that operate the network. I shared my thoughts about how the Internet and privacy might evolve in the interview in [Opt Out Podcast](https://optoutpod.com/episodes/s3e02-simplexchat/).
+
+### How is it funded and what is the business model?
+
+We started working full-time on the project in 2021 when [Portman Wills](https://www.linkedin.com/in/portmanwills/) and [Peter Briffett](https://www.linkedin.com/in/peterbriffett/) (the founders of [Wagestream](https://wagestream.com/en/) where I led the engineering team) supported the company very early on, and several other angel investors joined later. In July 2022 SimpleX Chat raised a pre-seed funding from the VC fund [Village Global](https://www.villageglobal.vc) - its co-founder [Ben Casnocha](https://www.villageglobal.vc/team/ben-casnocha) was very excited about our vision of privacy-first fully decentralized messaging and community platform, both for the individual users and for the companies, independent of any crypto-currencies, that might grow to replace large centralized platforms, such as WhatsApp, Telegram and Signal.
+
+> Edit: please see the comment from Ben Casnocha about this investment in [our post from August 14, 2024](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md).
+
+Overall we raised from our investors approximately $370,000 for a small share of the company to allow the project team working full time for almost two years, funding product design and development, infrastructure, and also [the security assessment by Trail of Bits](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md). A large part of this money is not spent yet.
+
+The project was hugely supported by the users as well - collectively, [you donated](https://github.com/simplex-chat/simplex-chat#help-us-with-donations) over $25,000. Without these donations the investment we raised would not be possible, because we believe that voluntary user donations can sustain the project in the long term – it already covers all infrastructure costs. There are only two ways an Internet service can exist - either users are paying for it, or the users data becomes the product for the real customers, as happened with many large Internet companies. In the latter case the users are losing much more money than they are saving by giving away their privacy and the rights to the content they create on the centralized platforms.
+
+Going forward we plan to keep the basic usage of the platform free, and at the same time we will be providing the benefits to the project sponsors. For example, there will be additional app icons and user profile badges. There also will be higher file transfer limits – currently we don't limit it at all, only limiting the file size, but it's unlikely to be sustainable. In any case, the app will remain highly usable for everyone for free, and fully open-source. Several other apps are already being developed based on our app core, leading to a fully decentralized network.
+
+### What is next?
+
+Our goals for the next 1-2 years are to make the messaging network:
+- more reliable and resilient, by adding redundancy into the message delivery and delivery receipts,
+- more private, by automating rotation of the servers used to deliver messages and by adding delivery relays to better protect IP addresses of the users,
+- more usable by adding and improving the functions users are expecting in messengers, and also adding some unique functions, like we did with [incognito mode](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#incognito-mode), [live messages](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.md#live-messages) and [hidden profiles](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.md#hidden-chat-profiles).
+
+One major initiative we will kick-off this year is the support for large, fully decentralized and private communities and groups not hosted on any servers – something that no Internet platform achieved so far in as private and efficient way as we plan to build it.
+
+To accelerate product development and growth we will be raising a seed funding this year, both from the VCs and angel investors, and we also might offer our users an opportunity to participate in the crowd funding round on the same terms as other investors, allowing to both support the project and to benefit from its future growth. [Subscribe to our updates](https://simplex.chat#join-simplex) not to miss it, connect to the team in SimpleX Chat and [join users' groups](https://github.com/simplex-chat/simplex-chat#join-user-groups).
+
+## What's new in v5.0
+
+### Send videos and files up to 1gb!
+
+<img src="./images/20230422-video.png" width="288" class="float-to-left">
+
+In the beginning of March [we released servers and command-line utility to send and receive files via XFTP protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md) - a very private and secure protocol that sends end-to-end encrypted files in chunks, protecting meta-data better than any alternatives we know of.
+
+Now this protocol is fully integrated in SimpleX Chat, and all files except small voice messages are sent using this protocol (small voice messages are sent as usual messages). Not only it is much faster than before - with the fast Internet connection I can send 25Mb file in 3 seconds and 1gb file in 2 minutes (for most users it's capped at the available Internet bandwidth), it has two other major advantages making it more usable:
+
+- the file sent to a group has to be uploaded only once, regardless of the group size.
+- once the file is uploaded (it will have the tick), you no longer need to be online for your contact (or group members) to be able to receive it.
+
+As for the metadata privacy, it has similar guarantee to SimpleX Messaging Protocol. The files are sent via TLS 1.2/1.3, with the same server identity verification, TLS channel binding and upload authorization as used with SMP servers. But the file metadata is protected even if TLS is compromised, as there are no identifiers and ciphertext in common in server received and sent traffic, allowing to correlate only by sending and receiving time. Correlating by time becomes less efficient as the server traffic grows.
+
+We also added the ability to send videos in the chat, so they can be played right in the conversation or on full screen without leaving the app – thanks to the efficient and fast file transfer they are very usable.
+
+We also plan to add support for longer and higher quality voice messages, and also for sending full resolution images in the next versions.
+
+### App passcode
+
+<img src="./images/20230422-passcode1.png" width="288">    <img src="./images/20230422-passcode2.png" width="288">
+
+While we do think that app passcode does not increase security too much, compared with device passcode or biometric protection, there are cases when it may be preferable, and also many users really wanted that it is added.
+
+Now you can choose whether to use faster and more convenient system biometric authentication or to use a separate app passcode. You can choose which one to use when it is first offered, or switch later in the settings.
+
+### Networking improvements
+
+<img src="./images/20230422-socks.png" width="288" class="float-to-left">
+
+Two small improvements to the app networking capabilities were added in this version.
+
+Firstly, you can now make your self-hosted servers available on IPv6 addresses, and the app supports them as well. Please bear in mind that older clients won't be able to connect to you if you use IPv6 address, and also that some ISPs do not provide IPv6 addresses to their users, in which case they would also not be able to connect if IPv6 address is used. To allow connections in these cases you should make your servers available on some domain name that resolves to both IPv4 and IPv6 addresses, and use this domain name in the server address.
+
+Secondly, Android client now supports configuring host and port of the SOCKS proxy, allowing to use apps other than Orbot and also to run SOCKS proxy in the local network, to save mobile device battery.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[SimpleX Chat security assessment](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/#how-simplex-works).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/#why-ids-bad-for-privacy).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Visit our [website](https://simplex.chat) to learn more.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html b/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html
index 34967e4e0e..cb94a17335 100644
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+++ b/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.md b/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.md
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+# SimpleX Chat v5.1 released: message reactions and self-destruct passcode
+
+**Published:** May 23, 2023
+
+What's new in v5.1:
+
+- [message reactions](#message-reactions) 🚀
+- [improved messages](#improved-messages):
+  - [voice messages up to 5 minutes](#voice-messages-up-to-5-minutes-better-quality-playback-control).
+  - [custom time to disappear](#disappearing-messages-choose-any-time).
+  - [message editing history](#message-editing-history).
+- new design and [customizable themes](#customize-and-share-color-themes) that you can share!<sup>*</sup>
+- [self-destruct passcode](#self-destruct-passcode)
+
+There are lots of small improvements and fixes in this release:
+  - setting to disable audio/video calls per contact.
+  - group welcome message visible in a group profile - add the link to join the group there.
+  - fixes for sending files.
+  - configurable SOCKS proxy host and port<sup>*</sup>.
+  - improved calls on lock screen<sup>*</sup>.
+  - locale-dependent formatting of time and date<sup>*</sup>.
+
+Also, we added Japanese and Portuguese (Brazil)<sup>*</sup> interface languages, thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+\* These features are available in the Android version only.
+
+## Message reactions
+
+<img src="./images/20230523-reactions.png" width="288" class="float-to-left">
+
+No idea why it took us so long to add them – finally we have them, and they are great.
+
+We didn't like the view of other messengers plagued by 40 different reactions on a message, and we were not quite sure what can be done about it, so we initially decided to limit available reactions to just 6: thumbs up 👍, down 👎, smile 😀, tear 😢, heart ❤️ and rocket 🚀. But unlike some other messengers, we don't limit the reactions to just one per message - you can put up to 3.
+
+You can add them via the menu, or just by tapping the reaction already on the message.
+
+The next app version will allow prohibiting the reactions per conversation, as you asked. Some groups work better with more substantive responses.
+
+## Improved messages
+
+### Voice messages: up to 5 minutes, better quality, playback control
+
+<img src="./images/20230523-voice.png" width="288" class="float-to-left">
+
+Since [v4.3](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#instant-voice-messages) voice messages were sent in small 16kb chunks, so we had to limit them to 30-40 seconds for better user experience, as sending larger files would require the sender to be online.
+
+With the new XFTP protocol that allows sending files up to 1gb it is now possible to increase the message size - we decided to limit it at 5 min, increasing their quality 2x (the bitrate is increased from 16 to 32kbps). We also added a slider to control the playback.
+
+### Disappearing messages: choose any time!
+
+<img src="./images/20230523-disappearing1.png" width="288">    <img src="./images/20230523-disappearing2.png" width="288">
+
+Since [v4.4](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.md#disappearing-messages) disappearing messages were only configurable for the whole conversation, with a limited choice of allowed times between 30 seconds and 1 month.
+
+This version allows to configure the time for messages to disappear more granularly, in the range from 1 second to 3 months. You can also set a different time to disappear when you send the message (hold the Send button), as long as disappearing messages are enabled in the conversation.
+
+### Message editing history
+
+<img src="./images/20230523-info.png" width="288" class="float-to-left">
+
+I [wrote previously](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#irreversible-message-deletion) why we decided to require the recipient concent before the messages can be fully deleted by the sender - in short, it is to support recipient's data sovereignty and prevent the possibility of offensive messages being removed without any trace. By default, when the sender deletes the message it is marked as deleted, rather than fully deleted, and you can reveal the original message.
+
+You've found the workaround for it of course - it's enough to simply edit the message to hide the original content. This version adds a visible message editing history, together with other detailed information about when the message was sent, received or deleted, that wasn't visible in the conversation.
+
+## Customize and share color themes
+
+<img src="./images/20230523-theme.png" width="288" class="float-to-left">
+
+Android app now allows choosing between three color themes - Light, Dark and SimpleX (a dark blue theme). You can customize any theme by setting 9 different colors used in the app, including titles, menus, accent colors and colors for sent and received messages.
+
+You can share your theme with other users by exporting it to a file and sending to them. You can also [contribute your favorite themes](https://simplex.chat/docs/themes.md) to our GitHub repository.
+
+## Self-destruct passcode
+
+<img src="./images/20230523-self-destruct.png" width="288" class="float-to-left">
+
+This is something many of you asked before - when asked to enter the app passcode under duress, to be able to enter a special self-destruct code that would remove the app data. This feature is offered in many security tools, and now you can configure it in SimpleX Chat as well.
+
+To enable it:
+- go to app Settings > Privacy & security > SimpleX Lock.
+- switch lock mode to Passcode and, if necessary, enable lock – Self-destruct passcode will become available.
+- enable it, enter the main passcode and then enter and confirm self-destruct passcode.
+- optionally, you can set the new display name of the profile that will be created after the data was wiped. If it is left blank, a new empty profile will have a random name.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[SimpleX Chat security assessment](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/#how-simplex-works).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/#why-ids-bad-for-privacy).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Visit our [website](https://simplex.chat) to learn more.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html b/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.md b/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.md
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+# SimpleX Chat v5.2 released: message delivery receipts
+
+**Published:** July 22, 2023
+
+**What's new in v5.2:**
+- [message delivery receipts](#message-delivery-receipts) – with opt-out per contact!
+- [filter favorite and unread chats](#filter-favorite-and-unread-chats).
+- [more usable groups](#more-usable-groups):
+  - view full original replied message in info.
+  - share your address with your contacts and group members via your chat profile.
+  - search new and existing members.
+- [stability improvements](#stability-improvements):
+  - keep your connections working after restoring from backup.
+  - restart app (Android) or reconnect servers (iOS).
+  - more reliable switching of the receiving address.
+  - more stable message delivery.
+- other improvements:
+  - [better disappearing messages](#better-disappearing-messages).
+  - [prohibit message reactions](#prohibit-message-reactions).
+
+**Platform evolution:**
+- [problems of public groups](#problems-of-public-groups):
+  - why not all messages are received.
+  - how to cope with these problems.
+  - when will public groups be more usable.
+- [what about read receipts?](#what-about-read-receipts)
+
+## What's new in v5.2
+
+### Message delivery receipts
+
+<img src="./images/20230722-receipts.png" width="330" class="float-to-left">
+
+Most messaging apps add two ticks to sent messages – the first one to show that the message is accepted by the server, and the second – that it is delivered to the recipient's device. It confirms that the network is functioning, and that the message is not lost or delayed. SimpleX Chat now has this feature too!
+
+In some cases it may compromise recipients' privacy, as they show that the recipient is online, so we made sending delivery receipts optional – it can be disabled separately for each chat profile or contact. For the new chat profiles this feature is enabled by default.
+
+To avoid compromising your privacy, sending delivery receipts is disabled for all your existing chat profiles. The first time you start the app after the update, you will be offered to enable them for all [visible profiles](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.md#hidden-chat-profiles), and they can be enabled later via Privacy and Security settings.
+
+### Filter favorite and unread chats
+
+<img src="./images/20230722-filter.png" width="288" class="float-to-left">
+
+You can now mark your contacts and groups as _favorite_, to be able to find them faster. With filter enabled, you will only see favorite chats, chats that contain unread messages and also any unaccepted group invitations and contact requests.
+
+### More usable groups
+
+Active SimpleX Chat users know how broken the current group experience is, and that we plan some major overhaul of the groups protocol – more on that below. In the meanwhile, we added some simple features that make groups in their current state a bit more usable.
+
+#### What is this in reply to?
+
+<img src="./images/20230722-quoted.png" width="330" class="float-to-left">
+
+A major problem is that you can see replies to the messages you've not seen before - this would happen both when you just join the group, and didn't connect to most other members, and also when other new members join the group and they didn't yet connect to you – so literally all the time, and the bigger the group gets, the worse it becomes. While this problem cannot be solved without major group protocol changes, at least there is now ability to see the original message that was replied to via the message information.
+
+#### How to connect to this member?
+
+<img src="./images/20230722-search.png" width="330" class="float-to-left">
+
+To simplify direct connections with other group members, you can now share your SimpleX address via your chat profile, and group members can send you a contact request even if the group does not allow direct messages.
+
+#### How to find a member in the list?
+
+Large member lists (and also the long lists of contacts, if you have many of them) become hard to scroll through, so now there is a search in both lists.
+
+### Stability improvements
+
+This version fixes many long-standing problems with the message delivery, failed connections with group members (that also contributed to group fragmentation), and reduces traffic in groups (beta users experienced a traffic spike because of this fix, but it doesn't affect the final v5.2 release). It's not the end of the road to making SimpleX Chat as stable as mainstream messengers, but it is a big improvement.
+
+Please report the cases when messages are not delivered – delivery receipts should help with that.
+
+#### Messages failed to decrypt? Problem solved!
+
+Previously, a growing number of users had the issue when after restoring the chat database from backup, messages from some contacts failed to decrypt and were showing an error in the app.
+
+This happens due to double ratchet protocol protecting the integrity of end-to-end encryption after the compromise - [post-compromise security](https://simplex.chat/docs/glossary.md#post-compromise-security). The protocol logic does not allow to use the old version of the database to decrypt the message.
+
+v5.2 added the extension to the messaging protocol allowing to negotiate the new ratchet keys in such cases - both with the contacts and the group members. This requires a user action, and it resets the security code verification status for this contact or member – you need to verify it again to have the additional protection from [man-in-the-middle attacks](https://simplex.chat/docs/glossary.md#man-in-the-middle-attack).
+
+The negotiation of the new ratchet keys still happens via the end-to-end encrypted messages, as the protocol has two layers of end-to-end encryption, so it cannot be compromised by the messaging relays.
+
+You may still lose connection if you or your contact changed the receiving address after you made the backup, so make sure to make a new backup after any receiving address changes.
+
+#### Reconnect the servers
+
+While v5.2 solved many message delivery issues, there may be some others, but they are usually resolved with app restart. It was difficult to fully restart Android app, as there is a continuosly running background service for notifications that doesn't restart with the app. Now Android app has both Restart and Shutdown buttons that take background service into account.
+
+On iOS you can now pull down the list of conversations to reconnect to all relays without restarting the app.
+
+### Better disappearing messages
+
+You can now send a separate disappearing message if the chat preferences allow them, but do not have any time to disappear enabled – this applies both to groups and to contacts. You can also set the time to disappear up to 12 months.
+
+### Prohibit message reactions
+
+While most people like message reactions, some conversations make them inappropriate - you can disable them now.
+
+## Platform evolution
+
+### Problems of public groups
+
+As I wrote above, the major problem is that not all messages are received by all members, or, at least, they may be substantially delayed. Additional problems are various scenarios when the list of members gets out of sync for different members.
+
+How to cope with these problems?
+
+It really helps to only use one link shared with the members to join the group - the one created by the client that is most frequently online, ideally always online. This is sometimes confusing, as any group admin can create another group link, and share it with the members, and if this admin is not online, the new member won't be able to join.
+
+We will add new group features to manage fragmentation - there will be an option to fix the connection with the member that you failed to connect to by passing the link out-of-band. This can be particularly helpful for stable groups of 20-50 people where it's important to see all messages.
+
+In the long term, the only way to make groups usable is to move to a new design. We considered several options.
+
+#### Why not hosted groups with MLS?
+
+Initially, we considered the design with the dedicated servers, potentially self-hosted, that host groups. This design would require adopting MLS (or similar) protocol for group-wide key agreement. Unfortunately, this design is not sufficiently resilient and easier to censor than decentralized design. Also, MLS protocol is very complex to implement, requires a centralized component, and reduces forward secrecy. So we decided against this approach.
+
+#### Why not fully decentralized groups?
+
+We also [considered](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2023-05-02-groups.md) rumour-mongering protocol, where all members are equal and participate in message dissemination. The problem with this approach is that it adds a lot of traffic for all members, even those who mostly read messages. Also, it still requires establishing a fully connected graph, and with large groups it becomes prohibitively expensive and unreliable, given that many members join public groups for a limited time.
+
+#### Members host the groups
+
+We are now considering a middle-ground - the design where the owners and admins host the group, synchronising the state between them, receiving and re-broadcasting the messages between all members. This puts a higher burden on these members, but these clients can be hosted in the cloud, and also group owners have a larger incentive to maintain group integrity. At the same time, this design is better for the rest of the group members, as they don't need to establish connections with all other members, only with a limited number of "hosting" members, and it also better protects their privacy, due to the lack of direct connections between most members.
+
+This approach avoids the need for a group-wide key agreement protocol, as hosting members are expected to have access to all content anyway, so pair-wise ratchets are sufficient. At the same time the content remains end-to-end encrypted, and protected from the outsiders.
+
+This approach also simplifies moderation - the message that needs to be removed simply won't reach the members before it is moderated (in case of automatic or policy-based moderation).
+
+Discovery and content search in such groups will be provided via a dedicated discovery server that will participate in the group, provide an always-online client, and also automatic content moderation functionality - a possible approach to moderation is [described here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2023-05-22-groups-moderation.md).
+
+We really look forward to your feedback on this design.
+
+### What about read receipts?
+
+We have an approximately equal number of users who ask us to add receipts, and those who ask not to add them, even as optional.
+
+While read receipts provide some convenience to the message senders, they introduce a lot of stress for the recipients.
+
+As one of the users in the group wrote it: "The existence of read receipts in other platforms is exhausting and is often a source of undue stress. I have to make a decision to read something and let someone know that I have read something and decided not to respond or merely didn't have the time to respond. The outcome of that is a complex social negotiation with non-theoretical social fallout as a consequence. All in all, it's an invasion of privacy of being able to read things at the pace of the individual as opposed to the pace dictated by others... Most people don't need a read receipt, so leave it to a group of individuals to decide if having read receipts make sense to them for their workflow".
+
+Also read [this post](https://neilalexander.dev/2021/04/09/read-receipts-typing-notifs) about the damage from read receipts and other invasive features, like typing and presense notifications.
+
+There is also no discounting that the presense of read receipts functionality, even as opt-in, creates a social pressure to enable them, with the same consequences – there are many scenarios when they become non-optional in some relationships. So many users belive, and we share this view, that it is better not to have these features at all. We will be re-assessing this view.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[SimpleX Chat security assessment](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/#how-simplex-works).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/#why-ids-bad-for-privacy).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Visit our [website](https://simplex.chat) to learn more.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html b/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md b/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md
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+# SimpleX Chat v5.3 released: desktop app, local file encryption and improved groups
+
+**Published:** September 25, 2023
+
+**What's new in v5.3:**
+- [new desktop app!](#multiplatform-desktop-app)!
+- [directory service and other group improvements](#group-directory-service-and-other-group-improvements).
+- [encrypted local files and media with forward secrecy](#encrypted-local-files-and-media-with-forward-secrecy).
+- [simplified incognito mode](#simplified-incognito-mode).
+
+There are a lot of other improvements and fixes in this release:
+- improved app responsiveness and stability.
+- app memory usage is reduced by 40%.
+- new privacy settings: show last messages & save draft.
+- fixes:
+  - bug preventing group members connecting (it will only help the new connections).
+  - playing videos on full screen<sup>**</sup>.
+  - screen reader for messages<sup>**</sup>.
+  - reduced background crashes<sup>**</sup>.
+
+Also, we added 6 new interface languages: Arabic<sup>*</sup>, Bulgarian, Finnish, Hebrew<sup>*</sup>, Thai and Ukrainian - thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+\* Android app.
+
+\*\* iOS app.
+
+## Multiplatform desktop app
+
+<img src="./images/simplex-desktop-light.png" width="640">
+
+Thanks a lot to everybody who was testing the desktop app since July – it really helped to make it stable!
+
+To use desktop app you need to **create a new profile**. As SimpleX platform has no user accounts, it's not as simple as for centralized apps to access the same profile from two devices.
+
+The next app version will allow using your mobile profile from desktop app. For now, as a workaround, you can join groups from both mobile and desktop devices, and use small groups instead of direct conversations.
+
+When you start the app first time, you will be offered to **set database passphrase** – you have to memorize it, as there is no way to recover it. If you skip it, a random passphrase will be generated and stored on your desktop device as plaintext (unencrypted) – you can change it later.
+
+Other limitations of the desktop app:
+- you cannot send voice messages.
+- there is no support for calls yet.
+
+You can download the desktop app for Linux and Mac via [downloads page](https://simplex.chat/downloads/index.html). Windows version will be available soon.
+
+## Group directory service and other group improvements
+
+<img src="./images/20230925-directory.png" width="330" class="float-to-left">
+
+Directory service provides a way to search for public groups submitted by the users. To use it, you need to connect to it via SimpleX Chat, as you would connect to any other contact, and type some words to search.
+
+You can also create and register your group, with some limitations explained [here](https://simplex.chat/docs/directory.md).
+
+Other group improvements in this release:
+
+- you can send delivery receipts to the groups up to 20 members.
+
+- if the group settings allow it, you can send direct messages to group members even after you deleted the contact.
+
+- connections between members are made faster, and the bug that prevented the connections in some cases is fixed in this release.
+
+The next release will reduce the time it takes to send messages to the group, especially when there are many members or when you have a slow device storage.
+
+## Encrypted local files and media with forward secrecy
+
+<img src="./images/20230925-encrypted.png" width="330" class="float-to-left">
+
+All messages, files and media sent via SimpleX Chat were always end-to-end encrypted from the very beginning. SimpleX Chat uses double-ratchet algorithm with encrypted message headers, for the best possible meta-data protection.
+
+You contacts, groups and messages are stored in the local database on your device, and this database was encrypted from [v4.0 released a year ago](https://simplex.chat/blog/20220928-simplex-chat-v4-encrypted-database.md).
+
+But until this version all files and media in the app storage were not encrypted, and when you exported the chat archive, they were unencrypted there as well.
+
+From v5.3 all files and media (except videos, for now) are encrypted with a random symmetric key - in many cases they are encrypted before they are written to the storage. Local file encryption can be disabled via Privacy & Security settings, for example, if you need to access the files from the storage outside of the app.
+
+In addition to the videos that are stored unencrypted, there are other rare scenarios when the received files may be unencrypted in this release. Files have an open or closed lock icons to indicate whether they were encrypted locally. These limitations will be addressed in the next release. In any case, all files and media are always sent end-to-end encrypted, without any exceptions.
+
+The keys used to encrypt files locally are associated with the messages and stored in the encrypted database. If you delete a message with the attached file or media, the key will be irreversibly deleted as well. Even if an attacker gains access to your database passphrase later and to the copy of the encrypted file, they won't be able to decrypt the file.
+
+This approach provides forward secrecy for locally stored files, unlike file encryption schemes used in some other apps when the same passphrase is used for all files.
+
+## Simplified incognito mode
+
+<img src="./images/20230925-incognito.png" width="330" class="float-to-left">
+
+Incognito mode was [added a year ago](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md) to improve anonymity of your profile, but it was confusing for some users - it was a global setting, but it only affected the new connections.
+
+It is now simpler to use - you can decide whether to connect to a contact or join a group using your main profile at a point when you create an invitation link or connect via a link or QR code.
+
+When you are connecting to people you know you usually want to share your main profile, and when connecting to public groups or strangers, you may prefer to use a random profile.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[SimpleX Chat security assessment](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/#how-simplex-works).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/#why-ids-bad-for-privacy).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Visit our [website](https://simplex.chat) to learn more.
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
index b0995e8cb2..3b34c35ba5 100644
--- a/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
+++ b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md
new file mode 100644
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--- /dev/null
+++ b/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md
@@ -0,0 +1,149 @@
+# SimpleX Chat v5.4 - link mobile and desktop apps via quantum resistant protocol, and much better groups.
+
+**Published:** Nov 25, 2023
+
+**What's new in v5.4:**
+- [Link mobile and desktop apps via secure quantum-resistant protocol](#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol).
+  - ⚡️ Quick start - how to use it.
+  - How does it work?
+  - 🤖 Connecting to remote CLI.
+- [Better groups](#better-groups).
+  - [Faster to join and more reliable](#faster-to-join-with-more-reliable-message-delivery).
+  - [New group features](#new-group-features):
+    - create groups with incognito profile,
+    - block group members to reduce noise,
+    - prohibit files and media in a group.
+- [Better calls](#better-calls): faster to connect, with screen sharing on desktop.
+
+There are many [other improvements](#other-improvements) and fixes in this release:
+  - profile names now allow spaces.
+  - when you delete contacts, they are optionally notified.
+  - previously used and your own SimpleX links are recognized by the app.
+  - and more - see the [release notes](https://github.com/simplex-chat/simplex-chat/releases/tag/v5.4.0).
+
+## Link mobile and desktop apps via secure quantum-resistant protocol
+
+This release allows to use chat profiles you have in mobile app from desktop app.
+
+This is only possible when both devices are connected to the same local network. To send and receive messages mobile app has to be connected to the Internet.
+
+### ⚡️ Quick start - how to use it
+
+**On desktop**
+
+If you don't have desktop app installed yet, [download it](https://simplex.chat/downloads/index.html) and create any chat profile - you don't need to use it, and when you create it there are no server requests sent and no accounts are created. Think about it as about user profile on your computer.
+
+Then in desktop app settings choose *Link a mobile* - it will show a QR code.
+
+<img src="./images/20231125-desktop1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop4.png" width="510">
+
+**On mobile**
+
+In mobile app settings choose *Use from desktop*, scan the QR code and verify session code when it appears on both devices - it should be the same. Verifying session code confirms that the devices are connected directly via a secure encrypted connection. There is an option to verify this code on subsequent connections too, but by default it is only required once.
+
+<img src="./images/20231125-mobile1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile1a.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile4.png" width="170">
+
+The devices are now paired, and you can continue using all mobile profiles from desktop.
+
+If it is an Android app, you can move the app to background, but iOS app has to remain open. In both cases, while you are using mobile profiles from desktop, you won't be able to use mobile app.
+
+The subsequent connections happen much faster - by default, the desktop app broadcasts its session address to the network, in encrypted form, and mobile app connects to it once you choose *Use from desktop* in mobile app settings.
+
+### How does it work?
+
+The way we designed this solution avoided any security compromises, and the end-to-end encryption remained as secure as it was - it uses [double-ratchet algorithm](https://simplex.chat/docs/glossary.md#double-ratchet-algorithm), with [perfect forward secrecy](https://simplex.chat/docs/glossary.md#forward-secrecy), [post-compromise security](https://simplex.chat/docs/glossary.md#post-compromise-security) and deniability.
+
+This solution is similar to WhatsApp and WeChat. But unlike these apps, no server is involved in the connection between mobile and desktop. The connection itself uses a new SimpleX Remote Control Protocol (XRCP) based on secure TLS 1.3 and additional quantum-resistant encryption inside TLS. You can read XRCP protocol specification and threat model in [this document](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2023-10-25-remote-control.md). We will soon be [augmenting double ratchet](https://github.com/simplex-chat/simplex-chat/blob/master/docs/rfcs/2023-09-30-pq-double-ratchet.md) to be resistant to quantum computers as well.
+
+The downside of this approach is that mobile device has to be connected to the same local network as desktop. But the upside is that the connection is secure, and you do not need to have a copy of all your data on desktop, which usually has lower security than mobile.
+
+Please note, that the files you send, save or play from desktop app, and also images you view are automatically saved on your desktop device (encrypted by default except videos). To remove all these files you can unlink the paired mobile device from the desktop app settings – there will be an option soon allowing to remove the files without unlinking the mobile.
+
+### 🤖 Connecting to remote SimpleX CLI
+
+*Warning*: this section is for technically advanced users!
+
+If you run SimpleX CLI on a computer in another network - e.g., in the cloud VM or on a Raspberry Pi at home while you are at work, you can also use if from desktop via SSH tunnel. Below assumes that you have remote machine connected via SSH and CLI running there - you can use `tmux` for it to keep running when you are not connected via ssh.
+
+Follow these steps to use remote CLI from desktop app:
+1. On the remote machine add the IP address of your desktop to the firewall rules, so that when CLI tries to connect to this address, it connects to `localhost` instead: `iptables -t nat -A OUTPUT -p all -d 192.168.1.100 -j DNAT --to-destination 127.0.0.1` (replace `192.168.1.100` with the actual address of your desktop, and make sure it is not needed for something else on your remote machine).
+2. Also on the remote machine, run Simplex CLI with the option `--device-name 'SimpleX CLI'`, or any other name you like. You can also use the command `/set device name <name>` to set it for the CLI.
+3. Choose *Link a mobile* in desktop app settings, note the port it shows under the QR code, and click "Share link".
+4. Run ssh port forwarding on desktop computer to let your remote machine connect to desktop app: `ssh -R 12345:127.0.0.1:12345 -N user@example.com` where `12345` is the port on which desktop app is listening for the connections from step 3, `example.com` is the hostname or IP address of your remote machine, and `user` is some username on remote machine. You can run port forwarding in the background by adding `-f` option.
+5. On the remote machine, run CLI command `/connect remote ctrl <link>`, where `<link>` is the desktop session address copied in step 3. You should run this command within 1 minute from choosing *Link a mobile*.
+6. If the connection is successful, the CLI will ask you to verify the session code (you need to copy and paste the command) with the one shown in desktop app. Once you use `/verify remote ctrl <code>` command, CLI can be used from desktop app.
+7. To stop remote session use `/stop remote ctrl` command.
+
+## Better groups
+
+### Faster to join, with more reliable message delivery
+
+We improved the protocols for groups, by making joining groups much faster, and also by adding message forwarding. Previously, the problem was that until a new member connects directly with each existing group member, they did not see each other messages in the group. The problem is explained in detail in [this video](https://www.youtube.com/watch?v=7yjQFmhAftE&t=1104s) at 18:23.
+
+With v5.4, the admin who added members to the group forwards messages to and from the new members until they connect to the existing members. So you should no longer miss any messages and be surprised with replies to messages you have never seen once you and new group members upgrade.
+
+### New group features
+
+<img src="./images/20231125-group1.png" width="220" class="float-to-left"> <img src="./images/20231125-block.png" width="220" class="float-to-left">
+
+**Create groups with incognito profile**
+
+Previously, you could only create groups with your main profile. This version allows creating groups with incognito profile directly. You will not be able to add your contacts, they can only join via group link.
+
+**Block group members to reduce noise**
+
+You now can block messages from group members that send too many messages, or the messages you don't won't to see. Blocked members won't know that you blocked their messages. When they send messages they will appear in the conversation as one line, showing how many messages were blocked. You can reveal them, or delete all sequential blocked messages at once.
+
+**Prohibit files and media in a group**
+
+Group owners now have an option to prohibit sending files and media. This can be useful if you don't won't any images shared, and only want to allow text messages.
+
+## Better calls
+
+Calls in SimpleX Chat still require a lot of work to become stable, but this version improved the speed of connecting calls, and they should work for more users.
+
+We also added screen sharing in video calls to desktop app.
+
+## Other improvements
+
+This version also has many small and large improvements to make the app more usable and reliable.
+
+The new users and group profiles now allow spaces in the names, to make them more readable. To message these contacts in CLI you need to use quotes, for example, `@'John Doe' Hello!`.
+
+When you delete contacts, you can notify them - to let them know they can't message you.
+
+When you try to connect to the same contact or join the same group, or connect via your own link, the app will recognize it and warn you, or simply open the correct conversation.
+
+You can find the full list of fixed bugs and small improvements in the [release notes](https://github.com/simplex-chat/simplex-chat/releases/tag/v5.4.0).
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
index 7b1dea2c87..840d94f9e8 100644
--- a/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
+++ b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.md b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.md
new file mode 100644
index 0000000000..fcd69e8fe8
--- /dev/null
+++ b/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.md
@@ -0,0 +1,110 @@
+# SimpleX Chat: free infrastructure from Linode, v5.5 released with private notes, group history and a simpler UX to connect.
+
+**Published:** Jan 24, 2024
+
+[SimpleX Chat infrastructure on Linode](#simplex-chat-infrastructure-on-linode):
+- Free infrastructure.
+- SimpleX servers in Linode Marketplace.
+- High capacity messaging servers.
+
+What's new in v5.5:
+- [private notes](#private-notes)
+- [group history](#group-history)
+- [simpler UX to connect to other users](#simpler-ux-to-connect-to-other-users)
+- [message delivery stability and other improvements](#message-delivery-stability-and-other-improvements)
+
+Also, we added Hungarian (only Android) and Turkish interface languages, thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+SimpleX Chat Android app is now available in 20 languages!
+
+## SimpleX Chat infrastructure on Linode
+
+We chose Linode as our hosting provider as and they have been consistently reliable, cheaper than alternatives, with excellent support and great documentation.
+
+When Linode was acquired by Akamai, we were a bit nervous about how it may affect service quality. So far it's been working out quite well.
+
+As the usage of SimpleX network was growing, so did our hosting costs, and from being really small they started to become significant, particularly as we didn't yet manage to optimize the servers last year.
+
+Linode helped - we're really excited to announce that Akamai decided to support SimpleX Chat growth by accepting it into their [Linode Rise startup program](https://www.linode.com/linode-for-startups/).
+
+Thanks to this program:
+
+- we received free infrastructure for the first year up to $10,000 per month, no strings attached. It already saved us some money, and gave us enough time to optimize the servers - the latest version of the servers are much less costly to operate with the current traffic, and can support a much larger traffic within this limit. In the year 2 of the program we will receive 50% discount with unlimited traffic, and in year 3 - 25% discount.
+
+- Linode Marketplace now includes [SimpleX Chat messages and file servers](https://www.linode.com/marketplace/apps/simplex-chat/simplex-chat/) - you can get free $100 credits for the first 2 months and run your own servers in just a few clicks, and use them in SimpleX Chat apps. Anybody can submit their application to Linode marketplace, but dedicated support we have from Linode team via this program made it simpler.
+
+- Akamai solution engineers are helping us to design high capacity server solution, free of charge, so that a single host can provide horizontally scalable capacity for messaging, allowing for a much larger number of concurrent users on a single server address. Initially we considered using HAProxy, and the latest proof of concept uses OpenResty - a fork of Nginx with Lua script engine - to route requests from a single host to multiple SMP relays, reducing an overhead for the clients that would be configured with a smaller number of higher capacity servers. This project is still in progress, there will be more details as we roll it out.
+
+## What's new in v5.5
+
+### Private notes
+
+<img src="./images/20240124-notes1.png" width="220" class="float-to-left"> <img src="./images/20240124-notes2.png" width="220" class="float-to-left">
+
+*"Where do I put notes for myself?"* was a very common support question. There was a workaround - you could create an empty group, just with yourself, and use it to save notes, but it was not very convenient, and you could accidentally add members there.
+
+This version has a more convenient and private alternative - the Private notes. It looks like an ordinary conversation where you can put text messages, links with previews, and any media and files, but they are not sent anywhere - they are stored locally, only on your device, with encrypted files.
+
+You can access the Private notes created in mobile app from desktop app too, by linking a mobile and desktop apps - the feature [added in the previous version](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md). It allows to conveniently share files between the devices without sending them over the Internet.
+
+### Group history
+
+<img src="./images/20240124-history1.png" width="220" class="float-to-left"> <img src="./images/20240124-history2.png" width="220" class="float-to-left">
+
+In the previous version, when users joined groups, they only saw an empty conversation, and the notifications of being connected to other members. This version allows group admins sending recent group history to the new members - this option is enabled by default for new groups, and can be enabled for the existing groups in the preferences. So now new members can join the conversation as soon as they join.
+
+This does not mean that these messages are stored on any servers - the admin member that adds a new member to the group sends these messages directly when a new member joins. Groups are still fully decentralized, do not have any identity on the network, and fully private - only their members know they exist.
+
+That is, unless a group owner decides to make it public. Groups can be registered in [SimpleX groups directory](https://simplex.chat/contact#/?v=1-4&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2FeXSPwqTkKyDO3px4fLf1wx3MvPdjdLW3%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEAaiv6MkMH44L2TcYrt_CsX3ZvM11WgbMEUn0hkIKTOho%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion) to be discovered by the new members - group directory is also improved.
+
+### Simpler UX to connect to other users
+
+<img src="./images/20240124-connect1.png" width="220" class="float-to-left"> <img src="./images/20240124-connect2.png" width="220" class="float-to-left">
+
+SimpleX platform has no user accounts or identities, and while it improves metadata privacy, it also makes it harder to understand how to connect to other people, particularly for the new users who are not invited by the existing users.
+
+This version simplifies this interface by allowing to connect via the received link just by pasting the address into the search bar, as is common in many wallet apps and some other decentralized messengers. We also improved the interface of creating invitation links.
+
+We will continue working on improving and simplifying user interface throughout the year. Please send us any feedback and suggestions to the team's address available in the app.
+
+### Message delivery stability and other improvements
+
+One of the long standing issues was that message reception could get stuck in some rare occasions, and only get resumed once the app is fully restarted. As Android app includes an always-on notification service that runs in background, full restart should be done via the app settings.
+
+This version fixed many issues with message delivery stability and also added some diagnostics to identify any other cases when message delivery may stop. These fixes should also reduce battery usage, particularly on slow internet connections.
+
+Other improvements in this version:
+- you can now reveal secret messages by tapping. To send a secret message wrap in "#" characters, e.g. "\#password\#".
+- you can delete the last user profile, simplifying account deletion. If you have [hidden user profiles](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.md), they won't be deleted in this case, and will be accessible again once you create a new profile.
+
+## SimpleX platform
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html b/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
index a21ae944cb..c9c695ab20 100644
--- a/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
+++ b/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
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diff --git a/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md b/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md
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+# SimpleX Chat v5.6 beta: adding quantum resistance to Signal double ratchet algorithm
+
+**Published:** Mar 14, 2024
+
+This is a major upgrade for SimpleX messaging protocols, we are really proud to present the results of the hard work of our whole team on the [Pi day](https://en.wikipedia.org/wiki/Pi_Day).
+
+This post also covers various aspects of end-to-end encryption, compares different messengers, and explains why and how quantum-resistant encryption is added to SimpleX Chat:
+
+- [Why do we need end-to-end encryption?](#why-do-we-need-end-to-end-encryption)
+- [Why is encryption even allowed?](#why-is-encryption-even-allowed)
+- [End-to-end encryption security: attacks and defense.](#end-to-end-encryption-security-attacks-and-defense)
+  1. Compromised message size - mitigated by padding messages to a fixed block size.
+  2. Compromised confidentiality - mitigated by repudiation (deniability).
+  3. Compromised message keys - mitigated by forward secrecy.
+  4. Compromised long-term or session - mitigated by break-in recovery.
+  5. Man-in-the-middle attack - mitigated by two-factor key exchange.
+  6. "Record now, decrypt later" attacks - mitigated by post-quantum cryptography.
+- [How secure is encryption in different messengers?](#how-secure-is-end-to-end-encryption-in-different-messengers)
+- [Adding quantum resistance to Signal double ratchet algorithm.](#adding-quantum-resistance-to-signal-double-ratchet-algorithm)
+- [When can you start using quantum resistant chats?](#when-can-you-start-using-quantum-resistant-chats)
+- [Next for post-quantum crypto - all direct chats, small groups and security audit.](#next-for-post-quantum-crypto---all-direct-chats-small-groups-and-security-audit)
+
+## Why do we need end-to-end encryption?
+
+The objective of end-to-end encryption is to make any potential attackers, such as traffic observers or communication providers who pass the messages between senders and recipients, unable to recover *any* message content or meaningful information about the messages, even if these attackers possess very advanced computing and mathematical capabilities.
+
+While human eyes are unable to see any difference between simply scrambled and encrypted messages, the difference between unreadable scrambling and unbreakable encryption can be as huge as just a few seconds to unscramble a message on an average laptop and more time than the Universe existed required to break the encryption on the most powerful computer in the world.
+
+Achieving the latter requires a lot of mathematical precision in both the cryptographic algorithms and in how they are used, and effectively makes encrypted messages indistinguishable from random noise, without any discoverable patterns or statistical irregularities that a computer could use to break the message encryption any faster than it it would take to try every possible combination of bits in the key.
+
+End-to-end encryption is an important component of our individual and business security, privacy and sovereignty. Having our private communications protected from any observers is both the natural condition and our inalienable human right.
+
+It's very sad to see the same people who keep their financial affairs private to protect from financial crimes, lock their doors to protect from thieves, and curtain their windows to protect from the occasional prying eyes, when it comes to protecting their personal lives from the data criminals say "we don't care about privacy, we have nothing to hide". Everybody's safety depends on keeping their affairs and relations private, not visible to a vast and ruthless data gathering machines, that abuse our data for commercial gain, without any regard to our interests or even [the safety of our families and children](https://nmdoj.gov/press-release/attorney-general-raul-torrez-files-lawsuit-against-meta-platforms-and-mark-zuckerberg-to-protect-children-from-sexual-abuse-and-human-trafficking/).
+
+## Why is encryption even allowed?
+
+<img src="./images/20240314-djb.jpg" class="float-to-right">
+
+If encryption is such a powerful tool to protect our lives, it also can be used to conceal crimes, so why the governments don't consider it similar to arms, and don't heavily regulate its use?
+
+Prior to 1996 the cryptography was considered munition, and its export from the United States was controlled under this category, [alongside flamethrowers and B-1 bombers](https://cr.yp.to/export/1995/0303-eff.txt). When [Daniel J. Bernstein](https://en.wikipedia.org/wiki/Daniel_J._Bernstein) (DJB), then a student of Mathematics at University of California, Berkeley, wanted to publish the paper and the source code of his Snuffle encryption system, the Office of Defense Trade Controls of the Department of State (DOS) after more than a year of correspondence requested that DJB registers as the arms dealer.
+
+In 1995 DJB represented by the Electronic Frontier Foundation brought a case against the DOS to overturn cryptography restrictions. The ruling in the case declared that the export control over cryptographic software and related technical data constitute [an impermissible infringement on speech in violation of the First Amendment](https://cr.yp.to/export/1996/1206-order.txt). This decision resulted in regulatory changes, reducing controls on encryption exports, particularly for open-source algorithms. The case continued until 2003, when it was put on hold after the commitment from the US government not to enforce any remaining regulations.
+
+This case is very important for the whole industry, as to this day we can freely create and use open-source cryptography without export control restrictions. It also shows the importance of engaging with the system and challenging its views in an open dialogue, rather than either blindly complying or violating regulations.
+
+DJB role for cryptography and open-source goes beyond this case – many cryptographic algorithms that are considered to be the most advanced, and many of which we use in SimpleX Chat, were designed and developed by him:
+
+- Ed25519 cryptographic signature algorithm we use to authorize commands to the servers.
+- NaCL library with cryptobox and secretbox constructions that combine X25519 Diffie-Hellman key agreement with Salsa20 encryption and Poly1305 authentication. We use cryptobox to encrypt messages in two of three encryption layers and secretbox to encrypt files.
+- Streamlined NTRU Prime algorithm for quantum resistant key agreement that we used in the protocol for linking mobile app with desktop, and now added to Signal double ratchet algorithm, as explained below.
+
+Without DJB's work the world would have been in a much worse place privacy- and security-wise.
+
+Daniel, we are really grateful for the work you did and continue doing. Thank you, and congratulations on the International Mathematics Day!
+
+## End-to-end encryption security: attacks and defense
+
+End-to-end encryption is offered by many messaging apps and protocols, but the security of different implementations are not the same. While many users know about the importance of forward secrecy - the quality of end-to-end encryption that preserves security of the encryption of the past messages, even if the keys used to encrypt some of the messages were compromised - there are many other qualities that protect from different attacks. Below there is the overview of these attacks and the properties of end-to-end encryption schemes that mitigate these attacks.
+
+### 1. Compromised message size - mitigated by padding messages to a fixed block size
+
+While the content encryption is the most important, concealing the actual message size is almost as important for several reasons:
+
+- attacker able to observe even approximate message sizes can use these sizes as an additional signal for machine learning to de-anonymise the users and to categorize the relationships between the users.
+- if a messenger conceals the routing of the messages to hide the transport identities (IP addresses) of senders and recipients, message sizes can be used by traffic observers to confirm the fact of communication with a much higher degree of certainty.
+
+The only effective mitigation to these attacks is to pad all messages to a fixed size. Using space-efficient schemes like Padme, or padding to encryption block size is ineffective for mitigating these attacks, as they still allow differentiating message sizes.
+
+To the best of our knowledge, the only messengers other than SimpleX Chat that pad all messages to a fixed packet size are Cwtch and no longer developed [Pond](https://github.com/agl/pond) - SimpleX design can be seen as an evolution of Pond design.
+
+### 2. Compromised confidential messages - mitigated by repudiation (deniability)
+
+Many users are very interested in having ability to irreversibly delete sent messages from the recipients devices. But not only would this ability violate data sovereignty of device owners, it is also completely ineffective, as the recipients could simply put the device offline or use a modified client app to ignore message deletion requests. While SimpleX Chat provides such features as [disappearing messages](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.md#disappearing-messages) and the ability to [irreversibly delete sent messages](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#irreversible-message-deletion) provided both parties agree to that, these are convenience features, and they cannot be considered security measures.
+
+The solution to that is well known to cryptographers - it is the quality of the encryption algorithms called "repudiation", sometimes also called "deniability". This is the ability of the senders to plausibly deny having sent any messages, because cryptographic algorithms used to encrypt allow recipients forging these messages on their devices, so while the encryption proves authenticity of the message to the recipient, it cannot be used as a proof to any third party.
+
+Putting it all in a simpler language - a sender can claim that the recipient forged messages on their device, and deny ever having sent them. The recipient will not be able to provide any cryptographic proof. This quality makes digital conversation having the same qualities as private off-the-record conversation - that's why the family of algorithms that provide these qualities are called off-the-record (OTR) encryption.
+
+Repudiation is still a rather new concept - the first off-the-record algorithms were proposed in 2004 and were only offered to a wide range of users in Signal messenger. This concept is still quite badly understood by users and society, and yet to have been used as the defense in any public court cases, as legal systems evolve much slower than technology. In high profile cases repudiation can be used as an effective evidence for the defense.
+
+Repudiation in messaging systems can be undermined by adding cryptographic signature to the protocol, and many messengers that use OTR encryption algorithms do exactly that, unfortunately. SimpleX Chat does not use signature in any part of client-client protocol, but the signature is currently used when authorizing sender's messages to the relays. v5.7 will improve deniability by enabling a different authorization scheme that will provide full-stack repudiation in all protocol layers.
+
+### 3. Compromised message keys - mitigated by forward secrecy
+
+The attacker who obtained or broke the keys used to encrypt individual messages, may try to use these keys to decrypt past or future messages. This attack is unlikely to succeed via message interception, and it is likely to require breaking into the device storage. But in any case, if the key was broken or obtained in some other way it's important that this key cannot be used to decrypt other messages - this is achieved by forward secrecy.
+
+This property is well understood by the users, and most messengers that focus on privacy and security, with the exception of Session, provide forward secrecy as part of their encryption schemes design.
+
+### 4. Compromised long-term or session - mitigated by break-in recovery
+
+This attack is much less understood by the users, and forward secrecy does not protect from it. Arguably, it's almost impossible to compromise individual message keys without compromising long-term or session keys. So the ability of the encryption to recover from break-in (attacker making a copy of the device data without retaining the ongoing access) is both very important and pragmatic - break-in attacks are simpler to execute on mobile devices during short-term device access than long-term ongoing compromise.
+
+Out of all encryption algorithms known to us only _Signal double ratchet algorithm_ (also referred to as _Signal algorithm_ or _double ratchet algorithm_, which is not the same as Signal messaging platform and protocols) provides the ability for the encryption security to recover after break-ins attacks. This recovery happens automatically and transparently to the users, without them doing anything special or even knowing about break-in, by simply sending messages. Every time one of the communication parties replies to another party message, new random keys are generated and previously stolen keys become useless.
+
+Double ratchet algorithm is used in Signal, Cwtch and SimpleX Chat. But Signal app by allowing to use the same profile on multiple devices compromises the break-in recovery function of Signal algorithm, as explained in [this paper](https://eprint.iacr.org/2021/626.pdf). Because of break-in recovery you cannot use SimpleX Chat profile on more than one device at the same time - the encryption scheme rotates the long term keys, randomly, and keys on another device become useless, as they would become useless for the attacker who stole them. Security always has some costs to the convenience.
+
+### 5. Man-in-the-middle attack - mitigated by two-factor key exchange
+
+Many people incorrectly believe that security of end-to-end encryption cannot be broken by communication provider. But end-to-end encryption is only as secure as key exchange. While any intermediary passing the keys between senders and recipients cannot recover the private keys from the public keys, they can simply replace the passed public keys with their own and then proxy all communication between the users having full access to the original messages. So instead of having an end-to-end encrypted channel, users would have two half-way encrypted channels - between users and their communication intermediary.
+
+Pictures below illustrate how this attack works for RSA encryption.
+
+#### 1) Alice sends the key to Bob (e.g. via p2p network or via the messaging server).
+
+![Public key is shared](images/20240314-mitm1.jpg)
+
+#### 2) Now Bob can send encrypted messages to Alice - he believes they are secure!
+
+![Message is encrypted](images/20240314-mitm2.jpg)
+
+#### 3) But the key could have been intercepted and substituted by Tom (the attacker, or a service provider).
+
+![Key is intercepted and replaced](images/20240314-mitm3.jpg)
+
+#### 4) Now the attacker can read the messages without Alice and Bob knowing.
+
+![End-to-end encryption is compromised](images/20240314-mitm4.jpg)
+
+The attack on Diffie-Hellman (or on quantum-resistant) key exchange, when both parties send their public keys (or public key and ciphertext), requires the attacker to intercept and replace both keys, but the outcome remains the same - if all communication is passed via a single channel, as it is usually the case with communication services, then any attacker that has inside access to the service can selectively compromise some of the conversations. Two years ago I wrote the post about this [vulnerability of end-to-end encryption to MITM attacks](https://www.poberezkin.com/posts/2022-12-07-why-privacy-needs-to-be-redefined.html#e2e-encryption-is-not-bulletproof).
+
+All known mitigations of this attack require using the secondary communication channel to ensure that the keys have not been substituted. The most secure approach is to make user's key (or key fingerprint) a part of the user's address or connection link, thus making two-factor key exchange non-optional. This approach is used in Session, Cwtch and SimpleX Chat.
+
+A less secure approach is to provide users an optional way to compare security codes - this is what is done by Signal, Element and many other messengers. The problem with this post-key-exchange verification is that it is optional, and is usually skipped by the majority of the users. Also, this security code can change because the user changed the device, or as a result of the attack via the service provider. When you see in the client app the notification that the security code changed, it's pointless to ask in the same messenger whether the device was changed, as if it were an attack, the attacker would simply confirm it. Instead, the security code needs to be re-validated again via another channel. A good security practice for the users would be to warn their communication partners about the intention to switch the device in advance, before the security code is changed.
+
+### 6. "Record now, decrypt later" attacks - mitigated by post-quantum cryptography.
+
+This is the idea based on the assumption that commercially viable quantum computers will become available during the next 10 years, and then they can use time-efficient [Shor's algorithm](https://en.wikipedia.org/wiki/Shor%27s_algorithm) developed in 1994 to break asymmetric encryption with quantum computer (symmetric encryption is not vulnerable to this algorithm).
+
+Post-quantum cryptography, or encryption algorithms that are resistant to quantum computers, has been the area of ongoing research for several decades, and there are some algorithms that _might_ protect from quantum computers. It's important to account for these limitations:
+
+- _none of the post-quantum algorithms are proven to be secure_ against quantum or conventional computers. They are usually referred to as "believed to be secure" by the researchers and security experts. There is continuous research to break post-quantum algorithms, and to prove their security, and many of these algorithms are broken every year, often by conventional computers.
+- because of the lack of proofs or guarantees that post-quantum cryptography delivers on its promise, these algorithms can only be used in hybrid encryption schemes to augment conventional cryptography, and never to replace it, contrary to some expert recommendations, as DJB explains in this [blog post](https://blog.cr.yp.to/20240102-hybrid.html).
+- they are much more computationally expensive and less space efficient, and the encryption schemes have to balance their usability and security.
+- many of post-quantum algorithms have known patent claims, so any system deploying them accepts the risks of patent litigation.
+- the silver lining to these limitations is that the risk of appearance of commercially viable quantum computers in the next decade may be exaggerated.
+
+So, to say it provocatively, post-quantum cryptography can be compared with a remedy against the illness that nobody has, without any guarantee that it will work. While there is a reasonable hope that it _might_ work, so it's not exactly a _snake oil_, these limitations and risks have to be much better communicated to the end users than they are.
+
+<img src="./images/20240314-datacenter.jpg" width="400" class="float-to-right">
+
+Does it mean that post-quantum cryptography is useless and should be ignored? Absolutely not. The risks of "record now, decrypt later" attacks are real, particularly for high profile targets, including millions of people - journalists, whistle-blowers, freedom-fighters in oppressive regimes, and even some ordinary people who may become targets of information crimes. Large scale collection of encrypted communication data is ongoing, and this data may be used in the future. So having the solution that _may_ protect you (post-quantum cryptography), as long as it doesn't replace the solution that is _proven_ to protect you (conventional cryptography), is highly beneficial in any communication solution, and has already been deployed in many tools and in some messengers.
+
+## How secure is end-to-end encryption in different messengers?
+
+This comparison may be incorrect in some of the columns. We apologize if some of the points are incorrect, please let us know about any mistakes so we can amend them!
+
+The main objective here is to establish the framework for comparing the security of end-to-end encryption schemes, and to highlight any areas for improvement, not to criticize any implementations.
+
+![Messengers comparison](images/20240314-comparison.jpg)
+
+<sup>1</sup> Repudiation in SimpleX Chat will include client-server protocol from v5.7 or v5.8. Currently it is implemented but not enabled yet, as its support requires releasing the relay protocol that breaks backward compatibility.
+
+<sup>2</sup> Post-quantum cryptography is available in beta version, as opt-in only for direct conversations. See below how it will be rolled-out further.
+
+Some columns are marked with a yellow checkmark:
+- when messages are padded, but not to a fixed size (Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes).
+- when repudiation does not include client-server connection. In case of Cwtch it appears that the presence of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+- when 2-factor key exchange is optional (via security code verification).
+- when post-quantum cryptography is only added to the initial key agreement and does not protect break-in recovery.
+
+## Adding quantum resistance to Signal double ratchet algorithm
+
+We have been exploring post-quantum cryptography since early 2022, when SimpleX Chat was first released, and we did not want to be pioneers here - cryptography is critically important to make it right.
+
+We hoped to adopt the algorithm that will be standardized by NIST, but the standardization process turned out to be hugely disappointing, and the ML-KEM (Kyber) algorithm that was accepted as a standard was modified to remove an important hashing step (see the lines 304-314 in [the published spec](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.203.ipd.pdf))), that mitigates the attacks via a compromised random numbers generator, ignoring strong criticism from many expert cryptographers, including DJB (see [this discussion](https://groups.google.com/a/list.nist.gov/g/pqc-forum/c/WFRDl8DqYQ4) and [the comments NIST received](https://csrc.nist.gov/files/pubs/fips/203/ipd/docs/fips-203-initial-public-comments-2023.pdf)). To make it even worse, the calculation of security levels of Kyber appears to have been done incorrectly, and overall, the chosen Kyber seems worse than rejected NTRU according to [the analysis by DJB](https://blog.cr.yp.to/20231003-countcorrectly.html).
+
+We also analyzed the encryption schemes proposed in Tutanota in 2021, and another scheme adopted by Signal last year, and published the design of [quantum resistant double ratchet algorithm](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2023-09-30-pq-double-ratchet.md) that we believe provides better security than these schemes:
+
+- unlike Tutanota design, it augments rather than replaces conventional cryptography, and also avoids using signatures when the new keys are agreed (ratchet steps).
+- unlike other messengers that adopted or plan to adopt ML-KEM, we used Streamlined NTRU Prime algorithm (specifically, strnup761) that has no problems of ML-KEM, no known patent claims, and seems less likely to be compromised than other algorithms - it is exactly the same algorithm that is used in SSH. You can review the comparison of [the risks of various post-quantum algorithms](https://ntruprime.cr.yp.to/warnings.html).
+- unlike Signal design that only added quantum resistance to the initial key exchange by replacing X3DH key agreement scheme with post-quantum [PQXDH](https://signal.org/docs/specifications/pqxdh/), but did not improve Signal algorithm itself, our design added quantum-resistant key agreements inside double algorithm, making its break-in recovery property also quantum resistant.
+
+The we could make break-in recovery property of Signal algorithm quantum-resistant, and why, probably, Signal didn't, is because irrespective of the message size SimpleX Chat uses a fixed block size of 16kb to provide security and privacy against any traffic observers and against messaging relays. So we had an extra space to accommodate additional ~2.2kb worth of keys in each message without any additional traffic costs.
+
+In case when the message is larger than the remaining block size, e.g. when the message contains image or link preview, or a large text, we used [zstd compression](https://en.wikipedia.org/wiki/Zstd) to provide additional space for the required keys without reducing image preview quality or creating additional traffic - our previously inefficient JSON encoding of chat messages was helpful in this case.
+
+<image src="./images/20240314-kem.jpg" alt="Double KEM agreement" width="500" class="float-to-right">
+
+The additional challenge in adding sntrup761 was that unlike Diffie-Hellman key exchange, which is symmetric (that is, the parties can share their public keys in any order and the shared secret can be computed from two public keys), sntrup761 is interactive key-encapsulation mechanism (KEM) that requires that one party shares its public key, and another party uses it to encapsulate (which is a fancy term for "encrypt" - that is why it has asterisks in the image) a random shared secret, and sends it back - making it somewhat similar to RSA cryptography. But this asymmetric design does not fit the symmetric operation of Signal double ratchet algorithm, where both sides need to generate random public keys and to compute new shared secrets every time messaging direction changes for them. So to achieve that symmetry we had to use two KEM key agreements running in parallel, in a lock-step fashion, as shown on the diagram. In this case both parties generate random public keys and also use the public key of another party to encapsulate the random shared secret. Effectively, this design adds a double quantum-resistant key agreement to double ratchet algorithm steps that provide break-in recovery.
+
+## When can you start using quantum resistant chats?
+
+<img src="./images/20240314-pq1.png" width="288"> <img src="./images/20240314-pq2.png" width="288"> <img src="./images/20240314-pq3.png" width="288">
+
+Quantum resistant double ratchet algorithm is already available in v5.6 (beta) of SimpleX Chat as an optional feature that can be enabled for the new and, separately, for the existing direct conversations.
+
+The reason it is released as opt-in is because once the conversation is upgraded to be quantum resistant, it will no longer work in the previous version of the app, and we see this ability to downgrade the app if something is not working correctly as very important for the users who use the app for critical communications.
+
+**To enable quantum resistance for the new conversations**:
+- open the app settings (tap user avatar in the top left corner).
+- scroll down to _Developer tools_ and open them.
+- enable _Show developer options_ toggle.
+- now you will see _Post-quantum E2EE_ toggle - enable it as well.
+
+Now all new contacts you add to the app will use quantum resistant double ratchet algorithm.
+
+Once you have enabled it for the new contacts, you can also **enable it for some of the existing contacts**:
+- open the chat with the contact you want to upgrade to be quantum resistant.
+- tap contact name above the chat.
+- tap Allow PQ encryption.
+- exchange several messages back and forth with that contact - the quantum resistant double ratchet will kick in after 3-5 messages (depending on how many messages you send in each direction), and you will see the notice in the chat once it enables.
+
+## Next for post-quantum crypto - all direct chats, small groups and security audit
+
+We will be making quantum resistance default for all direct chats in v5.7, and we plan that all existing direct chats will be automatically upgraded when both contacts install v5.7.
+
+We will also be adding quantum resistance to small groups up to 10-20 members. Computing cryptographic keys is much slower, in comparison, and it would be very inefficient (and completely unnecessary) for large public groups.
+
+We have also arranged a 3rd party cryptographic review of our protocol and encryption schemes design for June/July 2024 - it will cover the additions to SimpleX protocols since [the previous security audit](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md) in November 2022, including [XFTP protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md) we use for file transfers and quantum resistant Signal double ratchet algorithm we just released in this beta version.
+
+In November 2024 we will be conducting further implementation audit, with double the scope of our 2022 audit.
+
+Security audits are very expensive, as they require employing exceptionally competent engineers and cryptographers, and it does stretch our budgets - so any donations to help us cover the costs would be hugely helpful. 
+
+That's it for now!
+
+Thank you for helping us improve the app, and look forward to your feedback.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donates to SimpleX Chat!
+
+As I wrote, we are planning a 3rd party security audit for the protocols and cryptography design, and also for an app implementation, and it would hugely help us if some part of this $50,000+ expense is covered with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX network based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html b/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html
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diff --git a/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.md b/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.md
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+# SimpleX network: real privacy and stable profits, non-profits for protocols, v5.6 released with quantum resistant e2e encryption and simple profile migration
+
+**Published:** Mar 23, 2024
+
+SimpleX network: deliver real privacy via a profitable business and non-profit protocol governance:
+- [community and business interests are aligned](#community-and-business-interests-are-aligned).
+- [the journey to the decentralized non-profit protocol governance](#the-journey-to-the-decentralized-non-profit-protocol-governance).
+- [welcome, Esra’a](#welcome-esraa)!
+
+What's new in v5.6:
+- [quantum resistant end-to-end encryption](#quantum-resistant-end-to-end-encryption-beta) (BETA) – enable it for the new contacts.
+- [use the app during the audio and video calls](#use-the-app-during-the-audio-and-video-calls).
+- [migrate all app data to another device via QR code](#migrate-all-app-data-to-another-device-via-qr-code).
+
+There are many other improvements and fixes in this release:
+- group admins can block a member for all other members.
+- filtering chats no longer includes muted chats with unread messages.
+- and more - see the [release notes](https://github.com/simplex-chat/simplex-chat/releases/tag/v5.6.0).
+
+## SimpleX network: deliver real privacy via a profitable business and non-profit protocol governance
+
+### Community and business interests are aligned
+
+Some people in our users' community believe that there is a conflict between the business and the community interests. This view fails to see a bigger picture of how these interests are aligned. I wrote a blog post about it [here](https://www.poberezkin.com/posts/2023-10-31-why-privacy-impossible-without-venture-funding.html). Our goal is to grow the network and the ecosystem while enriching all stakeholders involved, both the community and the business shareholders. This strategy relies on the strengths and opportunities of both the business and the decentralized network we build, with its vibrant community of individuals and organizations. It positions the business not as a controller but as a supporter of the community growth, resilience and sustainability.
+
+By leveraging access to investment resources, its ability to provide stock-based incentives beyond salaries, operating as a business will satisfy users' and community needs more effectively, ensuring the long-term viability and growth of the network, while remaining true to the mission. A purely nonprofit model with no avenue to sustain this growth is simply not possible. Sustainability requires profits, that is simply spending less than earning, as every responsible individual and organization should aim for, and these profits must be based on users' payments, and not on some other sources of revenue or funds. And building the software product that customers are willing to pay for requires substantial business investments. We will accomplish it while maintaining transparency and the commitment to keep SimpleX network and its protocols open and free to use.
+
+### The journey to the decentralized non-profit protocol governance
+
+At the current early stage of network growth the protocols will benefit most from the rapid evolution and centralized design. Many protocols that decentralized their evolution too early failed to evolve and to adapt to the product requirements of the majority of users, causing them to stall in growth. Even the open web became possible only thanks to Netscape, a venture funded company, that developed browsers and web server software taking it upon themselves to rapidly evolve web specification to make it into a robust application platform as we now know it. It is very unlikely that it would have happened if it was managed by a nonprofit or community, in a decentralized way.
+
+Once SimpleX network protocols stabilize and reach the required maturity, we plan to transition its governance to several new nonprofit entities, ensuring its continued evolution aligns more closely with our vision of community-driven, independent and transparent governance. We and our investors believe that this is a win-win strategy. It both maximizes the business value, by creating a product built on protecting privacy and users' trust - a model that we see as the only viable path forward. It also maximizes the value created for the user community.
+
+### Welcome, Esra’a!
+
+To help us deliver these goals, Esra’a Al Shafei joined SimpleX Chat team - we are excited to welcome her!
+
+Esra'a is a longtime privacy and human rights advocate from Bahrain. She is the founder of [Majal.org](http://majal.org), a network of platforms that amplify under-reported and marginalized voices in the Middle East and North Africa. She is also the co-founder of the [Numun Fund](https://numun.fund/), the first dedicated fund for women-led tech in the Global South. Esra’a is currently the Vice Chair of the Board at the [Wikimedia Foundation](https://wikimediafoundation.org/), the nonprofit which hosts Wikipedia. She is also on the Board of the [Tor Project](https://www.torproject.org/), developers of one of the world’s strongest tools for privacy and freedom online. Previously, she served on the Board of [Access Now](https://www.accessnow.org/), an international nonprofit dedicated to an open and free Internet.
+
+In her own words: *"Privacy and security have been the center of my work as a human rights advocate for the last 20 years in one of the most surveilled countries in the world where staying safe remains a burden. Our privacy is our dignity. It is something that belongs to us and something we should treasure - as people, as companies, as governments. Despite messaging being the most intimate aspect of our digital lives, the leading protocols in this space are centralized and we deserve a web that operates on the core principles of genuine privacy and security in a fully decentralized framework. SimpleX network will play a critical role towards that vision."*
+
+Executing the plan towards decentralized nonprofit protocol governance will be Esra’a’s primary responsibility. Our primary objective with this plan is to ensure that no single entity can control or have unrestricted ownership of the protocols, so it can maintain its integrity.
+
+## What's new in v5.6
+
+### Quantum resistant end-to-end encryption (BETA)
+
+Adding post-quantum resistance to the double ratchet end-to-end encryption algorithm in SimpleX Chat is a major upgrade to messaging protocols, and it creates the security against the future quantum computers.
+
+I wrote in detail in the previous post about various properties of end-to-end encryption and how exactly quantum resistance is implemented in SimpleX Chat - currently SimpleX Chat has [the most secure end-to-end encryption design](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md#how-secure-is-end-to-end-encryption-in-different-messengers) against the present and future attacks.
+
+We plan to perform a security audit of this design and implementation later this year.
+
+Post-quantum encryption is currently added as opt-in and has to be separately enabled to be active for the new contacts, and, additionally, can be enabled for the existing contacts.
+
+<img src="./images/20240314-pq1.png" width="288"> <img src="./images/20240314-pq2.png" width="288"> <img src="./images/20240314-pq3.png" width="288">
+
+**To enable quantum resistance for the new conversations**:
+- open the app settings (tap user avatar in the top left corner).
+- scroll down to _Developer tools_ and open them.
+- enable _Show developer options_ toggle.
+- now you will see _Post-quantum E2EE_ toggle - enable it as well.
+
+Now all new contacts you add to the app will use quantum resistant Signal double ratchet algorithm.
+
+Once you have enabled it for the new contacts, you can also **enable it for some of the existing contacts**:
+- open the chat with the contact you want to upgrade to be quantum resistant.
+- tap contact name above the chat.
+- tap Allow PQ encryption.
+- exchange several messages back and forth with that contact - the quantum resistant double ratchet will kick in after 3-5 messages (depending on how many messages you send in each direction), and you will see the notice in the chat once it enables.
+
+We will be making quantum resistance default for all direct chats in v5.7, and we plan that all existing direct chats will be automatically upgraded when both contacts install v5.7.
+
+### Use the app during the audio and video calls
+
+<img src="./images/20240323-call1.png" width="220" class="float-to-left"> <img src="./images/20240323-call2.png" width="220" class="float-to-left">
+
+Since we added the audio and video calls in 2022 a lot of work was done to improve the stability of calls. One of the usability downsides until this release was that it was impossible to use the app during the call.
+
+This version solved this problem - now you can return back to the app without interrupting the call and use any of the app functions - for example, you can send the messages or files to the person you are in the call with. If this is a video call, you will continue seeing your contact in a small picture-in-picture view.
+
+### Migrate all app data to another device via QR code
+
+We always believed that cross-platform data portability is very important for any software. Users own their data, and they should have a way to export it from any software they use. So from the version of SimpleX Chat [released in July 2022](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#database-export-and-import) it was possible to export the database as a self-contained file, including all contacts, messages and files, and import it on a new device.
+
+_"How can I migrate my data to another device?"_ was one of the most frequent user questions, but until this release this process was [quite complex](), requiring too many steps, and most non-technical users were not willing to try it, as even though it was reliable, it appeared risky.
+
+This release made the app data migration very simple, see the steps below.
+
+**Start the migration on the source device**
+
+<img src="./images/20240323-migrate-from1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-from2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-from3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-from4.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-from5.png" width="170">
+
+On the device you migrate your app data from, follow these steps:
+- choose _Migrate to another device_,
+- if necessary, set the database passphrase (initially, the database is encrypted with a random passphrase), or, if it's already set, verify it - for security and to ensure that the archive will be usable on the new device,
+- tap _Archive and upload_ to and upload the app data in chunks to the XFTP servers configured in the app,
+- the app will show the QR code that should be scanned from the new device.
+
+**Migrate data to the target device**
+
+<img src="./images/20240323-migrate-to1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-to2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-to3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-to4.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20240323-migrate-to5.png" width="170">
+
+On the device you migrate your data to, follow these steps:
+- on the first app page choose _Migrate from another device_,
+- scan the QR code shown on the source device,
+- once the archive downloads, enter the database passphrase and tap _Open chat_,
+
+**Finalize migration on the source device**
+
+<img src="./images/20240323-migrate-from6.png" width="170" class="float-to-left">
+
+When the chat starts on the target device, make sure to tap _Finalize migration_ and then _Delete database_ on the source device.
+
+The database cannot be used on two devices at the same time, doing so would make it impossible to decrypt the received messages. This is a security measure - the break-in recovery property of double ratchet algorithm.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[How SimpleX is different from Session, Matrix, Signal, etc.](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#frequently-asked-questions).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donates to SimpleX Chat!
+
+As I wrote, we are planning a 3rd party security audit for the protocols and cryptography design, and also for an app implementation, and it would hugely help us if some part of this $50,000+ expense is covered with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX network based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html b/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html
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     <meta name="twitter:card" content="summary" />
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+    
+<link rel="alternate" type="text/markdown" href="/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
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diff --git a/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md b/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md
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+# Why I joined SimpleX Chat
+
+**Published:** Apr 4, 2024
+
+_By [Esra'a al Shafei](https://mastodon.social/@alshafei)_
+
+Transitioning from a lifelong career dedicated to nonprofits, including Board roles at organizations like the Wikimedia Foundation, Access Now and Tor, my decision to join SimpleX Chat may come as a surprise to some. But, as I step into this new chapter, I want to share the insights and convictions that have guided me here, shedding light on what I think sets SimpleX Chat apart and why this move feels like an essential learning opportunity.
+
+The nonprofit world has been my primary focus for decades. My team and I ran the platforms at Majal.org with an extremely limited budget. We had to navigate many complexities and challenges that shadow the nonprofit model. And because we worked primarily in creating applications and tools, a recurring theme has been financial sustainability. Being a Bahrain-based entity for most of these years meant that the many communities we served were not in a position to provide contributions and we were not eligible for most foundation grants. This drastically limited our growth and the reliability of our apps. When we failed to raise sufficient funds or meet our target budgets, we often had to shutter certain applications, sometimes after spending more than 10 years building them. 
+
+With secure and private messaging, the stakes are even graver. Any failure to commit and resource/fund ongoing development, security patches, etc means lives can be at risk. I still believe in nonprofit models, and it’s why I continue to serve them through various volunteer roles. I do also believe that there is room for a mixture of models that, in the case of something as unique as SimpleX Chat, can serve as a fully open and transparent public interest technology while also having a profitable values-aligned company that can keep the lights on to continue developing, expanding, and improving the protocol, network and their reach.
+
+I’m no stranger to writing about some VC models being [corrupt](https://mastodon.social/@alshafei/112125959080515656). Frankly, I also hold the view that some tech VCs are amongst the [most complicit](https://responsiblestatecraft.org/defense-tech/) in egregious war crimes worldwide, or enabling the [intrusive surveillance](https://mastodon.social/@alshafei/112140566088322925) we’re fighting against. So being part of a VC-funded venture is not a decision I take lightly. However, I have been following SimpleX Chat’s growth since early 2022 when I first met Evgeny at the Mozilla Festival. I appreciated the drive and Evgeny’s firm refusal to settle for the current models of private messaging. We share the belief that messaging is something we need to keep improving and that we must continue pushing its boundaries to make it even more private, secure, usable for groups, and, most importantly - fully decentralized. This is a major undertaking, and it requires funding to achieve. Candidly, I did worry about funding and sustainability because, at the time, SimpleX was still primarily funded by user contributions. 
+
+But even knowing this, I scrutinized SimpleX Chat for taking VC funding ($350K) from Village Global and questioned the individuals featured on its frontpage. I had to speak with Evgeny directly to learn who exactly from this fund was involved, how much power they wielded, if any, and if this changes the ethos of the company - all of which he is already making public. It was only after these discussions that I was comfortable to take a leap of faith and continue to use the app and vouch for its current and future offerings. It required me to question my own views on whether a VC-funded company can actually have major positive contributions to privacy as well as the open ecosystem. 
+
+<img src="./images/20240404-messsaging-apps.png" class="float-to-right" width="50%">
+
+The web has a long history of [trading privacy](https://www.engadget.com/from-its-start-gmail-conditioned-us-to-trade-privacy-for-free-services-120009741.html) for “free” services. Traditionally, these services have also been centralized, closed-source, non-transparent, and profit-oriented. The companies behind these apps and services became prolific because of their disregard of privacy rights, which normalized lucrative surveillance capitalism. There is such an extensive global monopoly that in Africa, only 1 of the 5 biggest messaging apps in Africa isn't owned by Meta, notoriously known for spying not just through its own apps but even through [its competitors](https://qz.com/project-ghostbusters-facebook-meta-wiretap-snapchat-1851366814), – relentless, massive data harvesting that stretches far beyond its own walled gardens:
+
+Some of the world’s top engineers often go to these companies because of the benefits and financial opportunities. We can question their ethics all day long, but we also need to question if the web would look significantly different if there were as many opportunities at privacy-first companies with purpose and strong, proven moral boundaries, set up in a way that can guarantee operational independence from any shareholders and VCs.
+
+SimpleX could have taken the route of other companies in the privacy space, whether it’s Skiff which rushed to take a large amount of [VC money](https://techcrunch.com/2022/03/30/skiff-series-a-encrypted-workspaces/) only to [shutter its doors](https://www.techradar.com/computing/cyber-security/skiff-gets-bought-by-notion-raising-privacy-concerns) after an acquisition, leaving its users hanging with many unanswered questions, or giving up control of the company, which would puts its future solely in the hands of VCs with majority ownership. SimpleX aims to prevent this, and in fact has left money on the table to ensure that it does not occur. Had it not been for this information, I would not have joined, and I would have remained a user of the product, albeit a very cautious one, constantly wondering whether it will be sold or corrupted. 
+
+It’s worth noting that some private foundations operate on the VC model in supporting nonprofits, either by requiring Board seats or requesting that their funding be used towards very specific objectives not always in alignment with the organization’s values and mission. It’s also worth noting that [some nonprofits](https://www.engadget.com/2019-05-31-sex-lies-and-surveillance-fosta-privacy.html) actually operate on the models of surveillance and censorship. Therefore, whether an organization or company is VC-backed or a nonprofit should not be the sole factor in deciding whether or not it is trustworthy. Actions are important, with full transparency being one of the most critical factors, and being fully open source being another to attract valid criticisms and audits to ensure any product or protocol lives up to its privacy and security promise. SimpleX Chat prides itself on being both transparent and open, on top of also being fully decentralized. If you’re new to it and eager to know more, you can start with [this overview](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md).
+
+Another important consideration is that the SimpleX network does have a plan that would rely on users' payments for specific or tailored services, and not on some other sources of revenue or funds (ads, etc.). Building anything that users would be willing to pay for requires substantially more time and resources, hence the VC route to establish a business model that doesn’t translate to the user being the product. But any business services need to be separate from SimpleX as a public interest technology. As outlined in this [recent post](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.md), I’ll be using my background in nonprofit governance structures to ensure that the SimpleX network protocols evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and decentralized governance. This would help create a necessary balance between different structures, in the same way many tech nonprofits also have for-profit subsidiaries to attract fee-for-service agreements to sustain their operations.
+
+In summary: My decision to join Simplex Chat, despite my deep-rooted beliefs and skepticism towards VC funding, reflects a broader realization: that the fight for privacy, security, and decentralization in today’s web is multifaceted and sometimes requires us to depart from our comfort zones to explore sustainable paths for continuous growth and impact so that open source privacy tools and protocols are no longer “niche”, but universally accessible standards. As long as nothing in this journey compromises our moral principles and integrity, this will remain a very worthwhile goal to pursue.
diff --git a/blog/20240416-dangers-of-metadata-in-messengers.html b/blog/20240416-dangers-of-metadata-in-messengers.html
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+    
+<link rel="alternate" type="text/markdown" href="/blog/20240416-dangers-of-metadata-in-messengers.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240416-dangers-of-metadata-in-messengers.md b/blog/20240416-dangers-of-metadata-in-messengers.md
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+# The dangers of metadata in messengers 
+
+**Published:** Apr 16, 2024
+
+_By [Esra'a al Shafei](https://mastodon.social/@alshafei)_
+
+In many countries around the world, phone numbers are attached to biometrics data and personal IDs. Telecommunications companies are either government owned or are heavily regulated, privately owned monopolies who comply with most government requests for backdoors or user data. The idea that today, we still need to give out our phone numbers as primary identifiers to be able to use the leading messaging apps should be frowned upon and actively challenged. It’s necessary to advocate for private alternatives in messaging that do not rely on user IDs of any kind - and yes, it’s possible. 
+
+Messaging is still not where it needs to be. Privacy is confused with security, when both are not synonymous, and there are major gaps in helping users understand the fundamental differences. 
+
+<img src="./images/20240416-whatsapp.jpg" class="float-to-right" width="38%">
+
+For example, while WhatsApp messages are [end-to-end encrypted](https://faq.whatsapp.com/820124435853543), let’s consider what you give up when you use it, per its own listings in app stores:
+
+- App activity (app interactions, in-app search history, and other user-generated content)
+- Location
+- Financial information (user payment info and payment history)
+- Contacts and their phone numbers
+- Groups you’re a member of
+- When you use the app and how often you use it 
+- Device and other IDs
+- Personal info (email address, user IDs, phone number)
+
+This is called [metadata](https://en.wikipedia.org/wiki/Metadata). It reveals a wealth of information about you and your connections, and in the hands of a centralized monopoly, this can and does get misused in incredibly dangerous ways. Once such metadata is logged, it can create very detailed profiles about who you are, everywhere you’ve been, and everyone you’ve ever spoken to. In settling for apps that normalize this while giving you the illusion of privacy in their marketing, we are doing ourselves a disservice by accepting this as the default. Collectively, we aren’t doing enough to protect ourselves and our social graph from this invasive overreach. 
+
+When stored, aggregated and analyzed, this metadata provides ample information that could potentially incriminate someone or be submitted to authorities. When WhatsApp and Facebook Messenger enabled end-to-end encryption for messages, of course it was a welcome and widely celebrated change. But it’s important to remember that not all end-to-end encryption utilizes the same standards, [some implementations are more secure](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md#how-secure-is-end-to-end-encryption-in-different-messengers) than others, so it’s something that shouldn’t necessarily be accepted at face value. More importantly: collecting and storing an obscene amount of metadata should invite global scrutiny, considering this data is often combined with whatever other information companies like Meta harvest about your identity (which is [a lot](https://www.vox.com/recode/23172691/meta-tracking-privacy-hospitals).)
+
+<img src="./images/20240416-metadata.png" class="float-to-right" width="38%">
+
+This is one of the many reasons why we need to resist giving out our phone numbers just to access an app, especially to do something as personal and intimate as private messaging. Even though users can sometimes mask their numbers with a username, their identity on the app is still fundamentally tied to their phone number. App operators have access to this, as well as user contacts. Additionally, with a simple modification to the app's source code, the contacts may also gain access in some cases. This should raise more concerns about privacy, and it makes the need for anonymity difficult to achieve. 
+
+Everyone has a different threat model (and if you don’t yet, now is a good time to [create one](https://www.privacyguides.org/en/basics/threat-modeling/#creating-your-threat-model)). For many users today, WhatsApp and other apps may be sufficient for their specific needs, especially in connecting with families and friends who are already on the app and unlikely to migrate elsewhere. If that suits your life and needs, and if you’re aware and consciously accept the risks, great. 
+
+But we also need to acknowledge that the world is becoming increasingly dangerous in the way AI is being used to [supercharge surveillance](https://www.forbes.com/sites/forbestechcouncil/2024/02/02/artificial-intelligence-the-new-eyes-of-surveillance/?sh=cd57bc214f27), and we need to be educated and aware of the risks this is already having on our lives and what it subjects others in your network to when you choose metadata-heavy apps as your primary form of communication. Having alternatives will always be important, even if it’s not what you default to for everyday messaging. Recognize who in your social circles might require the extra privacy, anonymity and security, so that you can play a role in protecting vulnerable individuals who need it most. The messaging app you choose implicates others as well, not just yourself, and while you personally may not require complete privacy, others might have their lives depend on it.
+
+End-to-end encryption is a solid start, but it's just the beginning of our pursuit for true privacy and security. True privacy means that even when legal demands come knocking, there's no useful metadata to hand over. It's not enough to just protect the content of messages; we need consistent innovation in protecting metadata too.
+
+Changing ingrained habits is tough, but your privacy is always worth the fight. Although giants like WhatsApp and Telegram may dominate global messaging for now, increasing concerns about data harvesting and AI-driven surveillance are fueling demand for alternatives. SimpleX Chat aims to be one of those strong alternatives, hence its radical focus on a decentralized framework with no user identifiers (in other words, nothing that uniquely identifies users on the protocol level to their contacts or to the relays) and extra optionality (self-hosting an [SMP server](https://simplex.chat/docs/server.md) or [XFTP server](https://simplex.chat/docs/xftp-server.md), access via Tor, [chat profiles](https://simplex.chat/docs/guide/chat-profiles.md) with incognito mode, etc.)
+
+As of today, most messaging alternatives, including SimpleX, will have some limitations. But with the limited resources we have, we are committed to daily progress towards creating a truly private messenger that anyone can use while maintaining the features that users have come to know and love in messaging interfaces. We want to be the prime example of a messenger that achieves genuine privacy without compromising it for convenience. We need to be able to reliably move away from small and niche use cases to endorsing and enforcing global standards for privacy and making it accessible for all users regardless of their technical expertise. 
+
+We’re grateful for the users and [donors](https://github.com/simplex-chat/simplex-chat#help-us-with-donations) who have been following along on this journey thus far and helping with feedback, anything from bug reports to identifying potential risks. Building in the open has always been a necessity for transparency and ongoing [auditability](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md), because we don’t want anyone to just take our word for it. [See for yourself](https://github.com/simplex-chat) and engage in the discussions. We fully expect you to hold us accountable to our word.
diff --git a/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.html b/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.html
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     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md b/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md
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+# SimpleX network: legally binding transparency, v5.7 released with better calls and messages
+
+**Published:** Apr 26, 2024
+
+What's new in v5.7:
+- [quantum resistant end-to-end encryption](#quantum-resistant-end-to-end-encryption) with all contacts.
+- [forward and save messages](#forward-and-save-messages) without revealing the source.
+- [in-call sounds and switching sound sources](#in-call-sounds-and-switching-sound-sources).
+- [better network connection management](#network-management).
+- [customizable profile images](#customizable-shape-of-profile-images)
+
+Also, we added Lithuanian interface language to the Android and desktop apps, thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+## Legally binding transparency
+
+We are committed to open-source, privacy and security. Here are the recent changes we made:
+
+- We now have a [Transparency Reports](https://simplex.chat/transparency/index.html) page.
+- We updated our [Privacy Policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md) to remove undefined terms "impermissible" and "acceptable", which would allow us to remove anything we don't like, without any clarity on what that is. You can see the edits [here](https://github.com/simplex-chat/simplex-chat/pull/4076/files).
+- We published a new page with [Frequently Asked Questions](https://simplex.chat/faq/index.html), thanks to the guidance from users.
+- We also have a new [Security Policy](https://simplex.chat/security/index.html) – we welcome your feedback on it.
+
+What do we mean by “legally binding transparency?”. It includes these principles:
+- Accountability: an empty promise or commitment to transparency that is not legally binding is just marketing, and can provide opportunities for the organizations to be misleading or not disclose important information that can affect their users privacy and security.
+- Consistency: often, there's a disconnect between marketing claims and legally binding policies. Our approach is to ensure that promises made in marketing materials or any external communications align with our legally binding documents, so that users can rely on our promises, and know exactly what to expect from us. 
+
+For example:
+- we use open-source code, and we made a legally binding commitment to use the published code in all released apps and deployed preset servers.
+- we use precise and technical language in the Privacy Policy defining what data and metadata can be accessed via the preset relays.
+
+If you see any inconsistency between technical parameters of SimpleX Network and what is promised in our Privacy Policy please raise it with us.
+
+## What's new in v5.7
+
+This release focus is improving the app usability, and preparing the foundation for v5.8 that will provide an in-built protection of user IP addresses when connecting to unknown file and messaging servers, reducing the need to use Tor (which would still remain supported via SOCKS proxy, for additional privacy).
+
+### Quantum resistant end-to-end encryption
+
+<img src="./images/20240426-pq.png" width="288" class="float-right">
+
+We [wrote before](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md) about how quantum resistant encryption was added to SimpleX Chat and also about other properties of end-to-end encryption, possible attacks on its security and known mitigations.
+
+Quantum resistant encryption will now be enabled by default in all direct chats. For the new conversations it will be enabled from the beginning, and for the existing conversations it will be agreed after you exchange several messages with your contacts - you will see a notice in the conversation when it happens.
+
+You can still safely downgrade the app to an earlier version if needed, as v5.6 already supports quantum resistant encryption.
+
+With the users who have an earlier version, the app will work using the conventional encryption, which is still very secure. It's important that we augmented the conventional encryption with post-quantum cryptographic algorithm rather than replaced it, using a hybrid construction as recommended by the cryptography experts.
+
+The groups currently do not support quantum resistant encryption yet - we plan to add it in the future to small groups.
+
+### Forward and save messages
+
+You can now save received messages to private notes and forward them to your contacts and groups. This is both more convenient than copy-pasting the messages, and also more private - you can forward files and preserve a disappearing file in your private notes without saving them outside of the app.
+
+You can see and navigate to the original source of the message via the message information, but the recipient of the message can only see that it was forwarded, but not from which conversation - in this way you can show that the message was quoted from another source without revealing the source ([Chatham House Rule](https://en.wikipedia.org/wiki/Chatham_House_rule)).
+
+<img src="./images/20240426-forward1.png" width="288"> <img src="./images/20240426-forward2.png" width="288"> <img src="./images/20240426-forward3.png" width="288">
+
+### In-call sounds and switching sound sources
+
+This was the most frequent request of the users who use SimpleX Chat for audio and video calls - to add sound indication to the connection progress, as happens in all other apps. This release added these sounds and also vibration when call connects and disconnects.
+
+You can also switch between bluetooth headphones, speakerphone and earpiece via the new button in the call.
+
+### Network management
+
+To reduce traffic and battery usage, this release made connection timeouts dependent on which network your device uses - timeouts will be larger when you are on mobile connection and smaller when on WiFi. It also makes connection attempts very infrequent when the device is not connected to network.
+
+### Customizable shape of profile images
+
+To customizable the interface, you can now change the shapes of profile images to anything from squares with sharp corners to circles, as before, via the Appearance menu in the app Settings. The default shape of profile images is changed to squares with rounded corners.
+
+<img src="./images/20240426-profile1.png" width="288"> <img src="./images/20240426-profile2.png" width="288"> <img src="./images/20240426-profile3.png" width="288">
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donates to SimpleX Chat!
+
+We are planning a 3rd party security audit for the protocols and cryptography design in July 2024, and also the security audit for an implementation in December 2024/January 2025, and it would hugely help us if some part of this $50,000+ expense is covered with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX network based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240516-simplex-redefining-privacy-hard-choices.html b/blog/20240516-simplex-redefining-privacy-hard-choices.html
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     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240516-simplex-redefining-privacy-hard-choices.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240516-simplex-redefining-privacy-hard-choices.md b/blog/20240516-simplex-redefining-privacy-hard-choices.md
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+# SimpleX: Redefining Privacy by Making Hard Choices
+
+**Published:** May 16, 2024
+
+When it comes to open source privacy tools, the status quo often dictates the limitations of existing protocols and structures. However, these norms need to be challenged to radically shift how we approach genuinely private communication. This requires doing some uncomfortable things, like making hard choices as it relates to funding, alternative decentralization models, doubling down on privacy over convenience, and more.
+
+There will always be questions on why the SimpleX Chat and network makes the choices it makes, and that’s good! It’s important to question us and to understand the reasoning behind each decision, whether it’s technical, structural, financial or any other.
+
+In this post we explain a bit more about why SimpleX operates and makes decisions the way it does.
+
+## No user accounts
+
+Within SimpleX network there are no user accounts, and more importantly, no user profile identifiers whatsoever at the protocol level, not even random numbers or cryptographic keys used to identify the users. This means there is absolutely nothing that uniquely links users to their contacts or to the network relays. While it's accurate to say, "You need an address to send something," it's crucial to understand that this "address" serves merely as a transient delivery destination, and not as a user profile identifier in any sense.
+
+You can read more about how SimpleX works [here](https://simplex.chat/#how-simplex-works).
+
+## Privacy over convenience
+
+One of the main considerations often ignored in security and privacy comparisons between messaging applications is multi-device access. For example, in Signal’s case, the Sesame protocol used to support multi-device access has the vulnerability that is [explained in detail here](https://eprint.iacr.org/2021/626.pdf):
+
+_"We present an attack on the post-compromise security of the Signal messenger that allows to stealthily register a new device via the Sesame protocol. [...] This new device can send and receive messages without raising any ‘Bad encrypted message’ errors. Our attack thus shows that the Signal messenger does not guarantee post-compromise security at all in the multi-device setting"_.
+
+<img src="./images/20231125-mobile2.png" width="170" class="float-right">
+
+Solutions are possible, and even the quoted paper proposes improvements, but they are not implemented in any existing communication solutions. Unfortunately this results in most communication systems, even those in the privacy space, having compromised security in multi-device settings due to these limitations. That's the reason we are not rushing a full multi-device support, and currently only provide [the ability to use mobile app profiles via the desktop app](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol), while they are on the same network.
+
+Another choice that compromises privacy for convenience and usability is 3rd party push notifications. At SimpleX, we take a slow path of optimizing the network and battery consumption in the app, rather than simply hiding inefficiencies behind the quick fix solution of 3rd party push notifications that [increases vulnerability](https://www.wired.com/story/apple-google-push-notification-surveillance/), a path Signal and others chose. Like other choices, it has usability and optimization trade offs, but ultimately it’s the right thing to continue progressing towards a better solution as we explain [here](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.html).
+
+Whenever possible, we strive to achieve significantly higher levels of privacy and security. For example, unlike most, if not all, applications (including Signal), [we encrypt application files with per-file unique key](https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html#encrypted-local-files-and-media-with-forward-secrecy). Consequently, once a message is deleted, there's no means to open a file that someone may have stolen in hopes of acquiring the key later. Similarly, apps like Session have done away with forward secrecy, a decision which caused them [not to be recommended](https://www.privacyguides.org/en/real-time-communication/#additional-options) for "long-term or sensitive communications". And [misinformation](https://simplifiedprivacy.com/spain-has-banned-telegram-defending-session/) around this makes it dangerous and irresponsible to recommend without such necessary disclosures for people’s awareness.
+
+Session’s decision was based on [the incorrect statements](https://getsession.org/blog/session-protocol-explained) about double ratchet being impossible in decentralized networks, and underplayed importance of forward secrecy, break-in recovery and deniability - the absence of these crucial qualities makes Session a much weaker choice for private messaging. For transparency, this was something that was debated with their team [here](https://twitter.com/SimpleXChat/status/1755216356159414602). We also made [a separate post](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md#end-to-end-encryption-security-attacks-and-defense) about these qualities of end-to-end encryption and their presence in different messengers, to show that not all end-to-end encrypted apps offer the same level of protections.
+
+## Network decentralization
+
+<img src="./images/simplex-explained.svg" width="40%" class="float-right">
+
+It's important to recognize that a model of decentralization where all servers are openly known and accessible to all clients, that some users ask for, actually results in a less decentralized network, and as the network grows it often requires an introduction of a central authority to protect from bad actors with malicious intent. Therefore, we've deliberately opted for a slower path towards achieving a higher degree of decentralization where there is no central server registry or network authority. For example, p2p designs may offer higher initial decentralization but often compromise on privacy and eventual decentralization. In essence, our approach prioritizes a balance between initial decentralization, privacy, and higher degree of decentralization down the line.
+
+Additionally, while it's true that we haven't yet established a model to incentivize other network operators, it's certainly on the roadmap. We see the decentralization of network operators offered within the app as a top priority. 
+
+Where it stands today, users have the freedom to select their preferred servers within the SimpleX network by configuring the app, with thousands of self-hosted servers in operation. Moreover, numerous third-party applications rely on our code for their in-app communications, operating independently of our servers, many of which we may not even be aware of.
+
+Decentralization is an ongoing journey, and we strive to proceed at a measured pace to ensure its proper implementation. While the immediate results may not always appear ideal, prioritizing a careful approach ensures that in the long run, the decisions made in this area align with our ultimate objectives of a private, efficient, reliable and fully decentralized network.
+
+## Funding and profitability
+
+We explain our rationale for funding [here](https://simplex.chat/faq/index.html#funding-and-business-model). Funding sources is always one of the most difficult choices to make, and it’s important to underline that VC models don’t necessarily translate to a quest for control, interference of any kind, or overall influence on product roadmap and strategy. The vast majority of investors seek profitability. Irrespective of the organization type profitability is essential for a sustainable operation, and it can and should be done while adhering to the highest possible standards for privacy. For-profit vs. nonprofit is also not an accurate metric to measure a commitment towards privacy and open standards, which is further explained [here](https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md).  
+
+To make a profit, satisfying customers is the key. Unlike the many companies that profit from selling customer data, we put user privacy first. Doing this at scale requires investments. If the investors don’t own or control a company, their participation becomes merely about profit for them, and not about how this profit is obtained. With the investors we have, we are completely aligned on this - they are betting on the future where privacy is the norm. They do not dictate on anything related to our model. We build SimpleX chat, protocols and network the way Internet should have been built if we as developers always put the privacy and empowerment of users first.
+
+## Company jurisdiction
+
+<img src="./images/20240516-parliament.jpg" width="40%" class="float-right">
+
+With regards to jurisdictions, nowhere is perfect. For that reason we plan to establish the foundations for protocol governance in [various jurisdictions](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html#the-journey-to-the-decentralized-non-profit-protocol-governance).
+
+But we’d like to clarify some misconceptions about the UK, where SimpleX Chat Ltd. is registered, and the UK legislation.
+
+For example, the Online Safety Act (OSA). Some people believe that it applies only to UK companies. But the OSA applicability isn’t determined by the company’s jurisdiction - it applies based on the nature and characteristics of the business and its services, as well as the number of its users in the UK. In case of SimpleX network, the OSA doesn’t apply for both of these reasons.
+
+The UK’s position on communication encryption, and more specifically, on end-to-end encrypted messaging, remains the subject of political debates. But with the OSA, the legislative intent was to propose technical measures to block CSAM, and it was trying to explore ways to do this via client-side scanning, which of course would undermine the encryption. However, and thanks to the hard work of privacy experts, researchers, academics and rights organizations throughout the UK and the rest of the world, the Online Safety Bill did not prohibit end-to-end encrypted apps without such scanners. It is an open question whether such technology will ever be possible, and the UK government made a public commitment that client-side scanning won't be required until it is.
+
+For now, strong end-to-end encryption remains permissible and protected, and we hope to also add to the privacy advocacy and debates as a UK-based company to keep it legally protected.
+
+Overall, we view the UK as being better jurisdiction for privacy than many alternatives - there are some trade-offs everywhere.
+
+## Looking ahead 
+
+The future of the Internet should be based on decentralized infrastructure operated by commercially viable organizations. These operators need to possess minimal user data, so that users have genuine control over their identities, and free from lock-in by the operators, to support fair competition. This requires a drastic re-imagining of the current norms and newer, more privacy-minded protocols. All in all, private messaging is surrounded by very difficult challenges but it’s worth it to keep pushing the industry forward and not settle for the status quo and current trade offs, protocol limitations and vulnerabilities. The Internet deserves better standards, and so do users.
diff --git a/blog/20240601-protecting-children-safety-requires-e2e-encryption.html b/blog/20240601-protecting-children-safety-requires-e2e-encryption.html
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     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240601-protecting-children-safety-requires-e2e-encryption.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240601-protecting-children-safety-requires-e2e-encryption.md b/blog/20240601-protecting-children-safety-requires-e2e-encryption.md
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+# Protecting Children's Safety Requires End-to-End Encryption
+
+As lawmakers grapple with the serious issue of child exploitation online, some proposed solutions would fuel the very problem they aim to solve. Despite expert warnings, the Belgian Presidency persists in pushing for the implementation of client-side scanning on encrypted messaging services, rebranding the effort as "upload moderation". Their [latest proposal](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM%3A2022%3A209%3AFIN&qid=1652451192472) mandates that providers of private communication services obtain user consent for AI-based scanning of their private chats. If users do not consent, they will be prohibited from sharing images, videos, and URLs.
+
+Privacy critics have long pushed for measures like centralized scanning of private photos and messaging data, arguing it could detect illicit content. However, invasive monitoring of private communications would create detrimental risks that far outweigh any perceived benefits.
+
+## Why we’re taking action
+
+SimpleX Chat signed a [joint statement](https://www.globalencryption.org/2024/05/joint-statement-on-the-dangers-of-the-may-2024-council-of-the-eu-compromise-proposal-on-eu-csam/) about the dangers of the EU compromise proposal on EU CSAM because maintaining end-to-end encryption is crucial for protecting privacy and security for everyone, including and especially children. 
+
+We urge the Ministers in the Council of the EU to stand firm against any scanning proposals that undermine end-to-end encryption, which would enable mass surveillance and misuse by bad actors, whether framed as client-side scanning, upload moderation, or any other terminology. Compromising this basic principle opens the door to devastating privacy violations. We also urge any organizations or individuals reading this to write to their representatives and voice their concerns. European Digital Rights has [outlined these issues](https://edri.org/our-work/be-scanned-or-get-banned/) in greater detail for anyone seeking more information.
+
+## Why compromising privacy endangers children
+
+The core issue is that compromising encryption and privacy makes innocent people vulnerable to malicious hackers and criminals seeking to exploit users data. Centralized scanning systems become a tempting target, potentially exposing millions of private family photos when breached. This would easily open up avenues for blackmail, abuse, and victimization of children. A case in point is the recent [criminal charges](https://techcrunch.com/2024/01/17/unredacted-meta-documents-reveal-historical-reluctance-to-protect-children-new-mexico-lawsuit/) against Meta in New Mexico, which highlights how the tech giant's algorithms enabled child exploitation by encouraging connections between minors and sexual predators. Privacy-eroding initiatives like client-side scanning would play into the hands of malicious actors by making more sensitive information accessible and weaponized in the same way that it has been on Meta platforms.
+
+## What should be done
+
+Rather than undermining privacy, to achieve child safety online users should be empowered with high standards for encryption and data control. For example, adopting a model where children (and users in general) cannot be discovered or approached on networks unless they or their parents permit it, similar to the SimpleX network privacy model. Intelligent multi-device synchronization could enable this oversight without compromising end-to-end encryption overall. It’s always possible to protect children without opening everyone, especially children themselves, to greater vulnerabilities due to such proposals.
+
+However, some recent legislative efforts have bizarrely moved in the opposite direction by seeking to limit parental access. The chilling truth is that the least private platforms have been major enablers of child exploitation. Eroding privacy protections on other services will only aid criminals further, not protect children. Preserving strong encryption and user privacy must be the foundation for any credible effort to combat online child exploitation. Initiatives trading privacy for supposed safety are not just technically flawed, but would achieve the exact opposite of their stated intent. We must avoid being gaslighted by narratives that defy logic, and instead provide users with the highest possible standards for privacy protections as a core principle.
+
+Protecting end-to-end encryption without carving out backdoors or vulnerabilities should be non-negotiable for children's and everyone’s safety. It is critical to redirect the discourse to focus on taking genuine privacy further by protecting against [metadata hoarding](https://simplex.chat/blog/20240416-dangers-of-metadata-in-messengers.html) and other means by which people’s data can be abused or subjected to surveillance.
diff --git a/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.html b/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.html
index 51e1dbe9e0..e301d420d2 100644
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md b/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md
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@@ -0,0 +1,161 @@
+# SimpleX network: private message routing, v5.8 released with IP address protection and chat themes
+
+**Published:** June 4, 2024
+
+What's new in v5.8:
+- [private message routing](#private-message-routing).
+- [server transparency](#server-transparency).
+- [protect IP address when downloading files & media](#protect-ip-address-when-downloading-files--media).
+- [chat themes](#chat-themes) for better conversation privacy - in Android and desktop apps.
+- [group improvements](#group-improvements) - reduced traffic and additional preferences.
+- improved networking, message and file delivery.
+
+Also, we added Persian interface language to the Android and desktop apps, thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+## Private message routing
+
+### What's the problem?
+
+<img src="./images/simplex-explained.svg" width="37%" class="float-right">
+
+SimpleX network design has always been focussed on protecting user identity on the messaging protocol level - there is no user profile identifiers of any kind in the protocol design, not even random numbers or cryptographic keys.
+
+Until this release though, SimpleX network had no built-in protection of user transport identities - IP addresses. As previously the users could only choose which messaging relays to use to receive messages, these relays could observe the IP addresses of the senders, and if these relays were controlled by the recipients, the recipients themselves could observe them too - either by modifying server code or simply by tracking all connecting IP addresses.
+
+To work around this limitation, many users connected to SimpleX network relays via Tor or VPN - so that the recipients' relays could not observe IP addresses of the users when they send messages. Still, it was the most important and the most criticized limitation of SimpleX network for the users.
+
+### Why didn't we just embed Tor in the app?
+
+Tor is the best transport overlay network in existence, and it provides network anonymity for millions of Internet users.
+
+SimpleX Chat has many integration points with Tor:
+- it allows [dual server addresses](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#using-onion-server-addresses-with-tor), when the same messaging relay can be reached both via Tor and via clearnet.
+- it utilises Tor's SOCKS proxy "isolate-by-auth" feature to create a new Tor circuit for each user profile, and with an additional option - for each contact. Per-contact [transport isolation](https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md#transport-isolation) is still experimental, as it doesn't work if you connect to groups with many members, and it's only available if you enable developer tools.
+
+Many SimpleX network design ideas are borrowed from Tor network design:
+- mitigation of [MITM attack](https://simplex.chat/docs/glossary.md#man-in-the-middle-attack) on client-server connection is done in the same way as Tor relays do it - the fingerprint of offline certificate is included in server address and validated by the client.
+- the private routing itself uses the approach similar to onion routing, by adding encryption layers on each hop.
+- we are also considering to implement Tor's [Proof-of-work DoS defence](https://blog.torproject.org/introducing-proof-of-work-defense-for-onion-services/) mechanism.
+
+So why didn't we just embed Tor into the messaging clients to provide IP address protection?
+
+We believe that Tor may be the wrong solution for some users for one of the reasons:
+- much higher latency, error rate and resource usage.
+- people who want to use Tor are better served by specialized apps, such as [Orbot](https://guardianproject.info/apps/org.torproject.android/).
+- Tor usage is restricted in some networks, so it would require complex configuration in the app UI.
+- some countries have legislative restrictions on Tor usage, so embedding Tor would require supporting multiple app versions, and it would leave the original problem unsolved in these countries.
+
+Also, while Tor solves the problem of IP address protection, it doesn't solve the problem of meta-data correlation by user's transport session. When the client connects to the messaging relays via Tor, the relays can still observe which messaging queues a user sends messages to via a single TCP connection. The client can mitigate it with per-contact transport isolation, but it uses too much traffic and battery for most users.
+
+So we believed we would create more value to the users of SimpleX network with private message routing. This new message routing protocol provides IP address and transport session protection out of the box, once released. It can also be extended to support delayed delivery and other functions, improving both usability and transport privacy in the future.
+
+At the same time, we plan to continue supporting Tor and other overlay networks. Any overlay network that supports SOCKS proxy with "isolate-by-auth" feature will work with SimpleX Chat app.
+
+### What is private message routing and how does it work?
+
+Private message routing is a major milestone for SimpleX network evolution. It is a new message routing protocol that protects both users' IP addresses and transport sessions from the messaging relays chosen by their contacts. Private message routing is, effectively, a 2-hop onion routing protocol inspired by Tor design, but with one important difference - the first (forwarding) relay is always chosen by message sender and the second (destination) - by the message recipient. In this way, neither side of the conversation can observe IP address or transport session of another.
+
+At the same time, the relays chosen by the sending clients to forward the messages cannot observe to which connections (messaging queues) the messages are sent, because of the additional layer of end-to-end encryption between the sender and the destination relay, similar to how onion routing works in Tor network, and also thanks to the protocol design that avoids any repeated or non-random identifiers associated with the messages, that would otherwise allow correlating the messages sent to different connections as sent by the same user. Each message forwarded to the destination relay is additionally encrypted with one-time ephemeral key, to be independent of messages sent to different connections.
+
+The routing protocol also prevents the possibility of MITM attack by the forwarding relay, which provides the certificate the session keys of the destination server to the sending client that are cryptographically signed by the same certificate that is included in destination server address, so the client can verify that the messages are sent to the intended destination, and not intercepted.
+
+The diagram below shows all the encryption layers used in private message routing:
+
+```
+-----------------             -----------------  -- TLS --  -----------------             -----------------
+|               |  -- TLS --  |               |  -- f2d --  |               |  -- TLS --  |               |
+|               |  -- s2d --  |               |  -- s2d --  |               |  -- d2r --  |               |
+|    Sending    |  -- e2e --  |    sender's   |  -- e2e --  |  recipient's  |  -- e2e --  |   Receiving   |
+|    client     |  message -> |  Forwarding   |  message -> |  Destination  |  message -> |    client     |
+|               |  -- e2e --  |     relay     |  -- e2e --  |     relay     |  -- e2e --  |               |
+|               |  -- s2d --  |               |  -- s2d --  |               |  -- d2r --  |               |
+|               |  -- TLS --  |               |  -- f2d --  |               |  -- TLS --  |               |
+-----------------             -----------------  -- TLS --  -----------------             -----------------
+```
+
+**e2e** - two end-to-end encryption layers between **sending** and **receiving** clients, one of which uses double ratchet algorithm. These encryption layers are present in the previous version of message routing protocol too.
+
+**s2d** - encryption between the **sending** client and recipient's **destination** relay. This new encryption layer hides the message metadata (destination connection address and message notification flag) from the forwarding relay.
+
+**f2d** - additional new encryption layer between **forwarding** and **destination** relays, protecting from traffic correlation in case TLS is compromised - there are no identifiers or cyphertext in common between incoming and outgoing traffic of both relays inside TLS connection.
+
+**d2r** - additional encryption layer between destination relay and the recipient, also protecting from traffic correlation in case TLS is compromised.
+
+**TLS** - TLS 1.3 transport encryption.
+
+For private routing to work, both the forwardig and the destination relays should support the updated messaging protocol - it is supported from v5.8 of the messaging relays. It is already released to all relays preset in the app, and available as a self-hosted server. We updated [the guide](https://simplex.chat/docs/server.md) about how to host your own messaging relays.
+
+Because many self-hosted relays did not upgrade yet, private routing is not enabled by default. To enable it, you can open *Network & servers* settings in the app and change the settings in *Private message routing* section. We recommend setting *Private routing* option to *Unprotected* (to use it only with unknown relays and when not connecting via Tor) and *Allow downgrade* to *Yes* (so messages can still be delivered to the messaging relays that didn't upgrade yet) or to *When IP hidden* (in which case the messages will fail to deliver to unknown relays that didn't upgrade yet unless you connect to them via Tor).
+See [F.A.Q. section](https://simplex.chat/faq/index.html#does-simplex-protect-my-ip-address) for answers about private message routing.
+
+Read more about the technical design of the private message routing in [this document](https://github.com/simplex-chat/simplexmq/blob/stable/rfcs/done/2023-09-12-second-relays.md) and in [the messaging protocol specification](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/simplex-messaging.md#proxying-sender-commands).
+
+## Server transparency
+
+<img src="./images/20240604-server.png" width="40%" class="float-to-right">
+
+Even with very limited information available to the messaging relays, there are [several things](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#simplex-messaging-protocol-server) that would reduce users' privacy that a compromised relay can do.
+
+We [wrote previously](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2024-03-20-server-metadata.md) that it is important that server operators commit to running unmodified server code or disclose any code modifications, and also disclose server ownership and any other relevant information.
+
+While we cannot require the operators of self-hosted and private servers to disclose any information about them (apart from which server code they use - this is the requirement of the AGPLv3 license to share this information with users connecting to the server), as we add other server operators to the app, it is important for the users to have all important information about these operators and servers location.
+
+This server release adds server information page where all this information can be made available to the users. For example, this is <a href="https://smp8.simplex.im" target="_blank">the information</a> about one of the servers preset in the app.
+
+The updated server guide also includes [the instruction](https://simplex.chat/docs/server.md#) about how to host this page for your server. It is generated as a static page when the server starts. We recommend using Caddy webserver to serve it.
+
+## More new things in v5.8
+
+### Protect IP address when downloading files & media
+
+This version added the protection of your IP address when receiving files from unknown file servers without Tor. Images and voice messages won't automatically download from unknown servers too until you tap them, and confirm that you trust the file server where they were uploaded.
+
+### Chat themes
+
+<img src="./images/20240604-theme1.png" width="244" class="float-to-right"> <img src="./images/20240604-theme2.png" width="244" class="float-to-right">
+
+In Android and desktop app you can now customize how the app looks by choosing wallpapers with one of the preset themes or choose your own image as a wallpaper.
+
+But this feature is not only about customization - it allows to set different colors and wallpaper for different user profiles and even specific conversations. You can also choose different themes for different chat profiles.
+
+In case you use different identities for different conversations, it helps avoiding mistakes.
+
+### Group improvements
+
+This version adds additional group configuration options to allow sending images, files and media, and also SimpleX links only to group administrators and owners. So with this release group owners can have more control over content shared in the groups.
+
+We also stopped unnecessary traffic caused by the members who became inactive without leaving the groups - it should substantially reduce traffic and battery consumption to the users who send messages in large groups.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Help us with donations
+
+Huge thank you to everybody who donates to SimpleX Chat!
+
+We are planning a 3rd party security audit for the protocols and cryptography design in July 2024, and also the security audit for an implementation in December 2024/January 2025, and it would hugely help us if some part of this $50,000+ expense is covered with donations.
+
+We are prioritizing users privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX network based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds – any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20240704-future-of-privacy-enforcing-privacy-standards.html b/blog/20240704-future-of-privacy-enforcing-privacy-standards.html
index f815ff4a4d..50a12bd730 100644
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+++ b/blog/20240704-future-of-privacy-enforcing-privacy-standards.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240704-future-of-privacy-enforcing-privacy-standards.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240704-future-of-privacy-enforcing-privacy-standards.md b/blog/20240704-future-of-privacy-enforcing-privacy-standards.md
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+# The Future of Privacy: Enforcing Privacy Standards
+
+**Published:** Jul 4, 2024
+
+Recent anti-privacy legislations and proposals in [Europe](https://www.theverge.com/2024/6/19/24181214/eu-chat-control-law-propose-scanning-encrypted-messages-csam), [the US](https://theconversation.com/section-702-foreign-surveillance-law-lives-on-but-privacy-fight-continues-229253) and [Australia](https://www.theguardian.com/technology/article/2024/jun/20/meredith-walker-signal-boss-government-encryption-laws) threaten to infringe our fundamental right to privacy and to create grave risks to the [safety](https://simplex.chat/blog/20240601-protecting-children-safety-requires-e2e-encryption.html) of children and vulnerable people. It's time we shift the focus: privacy should be a non-negotiable duty of technology providers, not just a right users must constantly fight to protect, and not something that users can be asked to consent away as a condition of access to a service.
+
+Tech giants are trying to normalize surveillance capitalism, often with little to no consequences globally. These companies are contributing to a growing ecosystem where opting out of invasive data hoarding practices is becoming increasingly challenging, if not outright impossible. We are being gaslit by the technology executives who try to justify profiteering from AI theft, from [Microsoft](https://www.computing.co.uk/news/4330395/microsoft-ai-chief-makes-questionable-claims-about-copyright-online-content) claiming all our content is fair game for their exploitation to unethical startups like [Perplexity](https://www.theverge.com/2024/6/27/24187405/perplexity-ai-twitter-lie-plagiarism) turning the word “[privacy](https://x.com/perplexity_ai/status/1789007907092066559)” into a marketable farce.
+
+## The AI Hype’s Impact on Privacy
+
+The exaggeration of AI’s actual capabilities and the continuous promotion of its “intelligence” is creating a rat race where tech companies and well-funded startups are evading accountability, as they eagerly collect and exploit more data than ever. 
+
+They're prioritizing AI development over user privacy and rights, setting a dangerous precedent for current and future online engagements. They've already normalized the use of AI to scan and analyze supposedly private communications - from emails to instant messages - repackaging this intrusion as "productivity tools”. Meanwhile, most consumers actually want [more data privacy](https://iapp.org/news/a/most-consumers-want-data-privacy-and-will-act-to-defend-it), not less, and are increasingly concerned by the lack of it.
+
+The legal push towards “client-side scanning”, attacks on end-to-end encryption and the support for pro-surveillance legislation gives credibility to these highly intrusive practices that literally endanger lives. And we know that moral obligations mean nothing to corporations benefiting from these exploitative models, so we have to ensure that our demands for privacy are legally enforceable and non-negotiable. 
+
+## Legal Action
+
+We are encouraged to see more legal pressure on companies that exploit user data on a daily basis. For example, the European Center for Digital Rights’ (Noyb) [complaints](https://noyb.eu/en/noyb-urges-11-dpas-immediately-stop-metas-abuse-personal-data-ai) against Meta’s abuse of personal data to train their AI and, and the demands from the Norwegian Consumer Council to data protection authority to ensure that applicable laws are enforced against Meta considering there is “[no way to remove personal data from AI models once Meta has begun the training](https://www.forbrukerradet.no/side/legal-complaint-against-metas-use-of-personal-content-for-ai-training/)”.
+
+Noyb is taking a strong stance against [other companies](https://noyb.eu/en/project/cases) with similar exploitative models, including facial recognition surveillance tools often misused by law enforcement agencies. Consider [supporting](https://noyb.eu/en/support) their ongoing efforts — we strongly believe legal action is one of the most effective means to hold these companies accountable for their persistent abuses, which are otherwise shielded by heavily funded self-serving lobby groups.
+
+## Privacy as a Legal Obligation
+
+We must shift from a defensive stance to a proactive one by proposing privacy legislation that puts users in direct control of their private data.
+
+This legislation should:
+1. Establish non-negotiable provider duties for protecting user privacy, with hefty fines and consequences for service operators who do not comply.
+2. Prevent providers from circumventing these duties through user consent clauses — it should be legally prohibited to ask for a consent to share user data or to use it for anything other than providing a service.
+3. Prevent providers from asking for any more personal information from the users than technically necessary and legally required. For example, asking for a phone number as a condition of access to a service should be made illegal in most cases — it does not provide a sufficient security, exposes users' private information and allows simple aggregation of users' data across multiple services.
+4. Create a strong legal framework that cannot be resisted or modified
+
+By codifying these principles into law, we can establish a strong technological framework that is built to create more value for end users, while protecting their privacy against data exploitation, criminal use and identity theft. We will continue the fight against illogical legislative proposals designed to normalize mass surveillance, but our efforts should equally gear towards creating and supporting new models and technological foundations that bring us far closer to the reality we urgently need.
+
+## Collective Action
+
+There is great work being done by advocacy organizations, and service providers need to contribute to this fight as well by shifting the narrative and reclaiming the term “privacy” from the tech giants who co-opted and corrupted it. We must play a bigger role in supporting users in setting stronger boundaries, making demands, and refusing anything less than genuine privacy and data ownership, while getting comfortable with holding providers accountable for any violations.
+
+Privacy should be seen as a fundamental obligation of technology providers, and legislators must actively enforce this expectation. The more consumers make this demand, the more pressure we put on anti-privacy lobbyists with rogue motives, the easier it will be to hold abusers accountable, and the more likely we can collectively ensure that a privacy-first web becomes a reality.
+
+You can support privacy today by signing [the petition](https://www.globalencryption.org/2024/05/joint-statement-on-the-dangers-of-the-may-2024-council-of-the-eu-compromise-proposal-on-eu-csam/) prepared by Global Encryption Coalition in support of communication privacy. You can also write to your elected representatives, explaining them how data privacy and encrypted communications protect children safety and reduce crime.
diff --git a/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.html b/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md b/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md
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+# SimpleX network: the investment from Jack Dorsey and Asymmetric, v6.0 released with the new user experience and private message routing.
+
+**Published:** Aug 14, 2024
+
+[SimpleX Chat: vision and funding 2.0](#simplex-chat-vision-and-funding-20):
+- [The past](#the-past-investment-from-village-global): investment from Village Global.
+- [The present](#the-present-announcing-the-investment-from-jack-dorsey-and-asymmetric): announcing the investment from Jack Dorsey and Asymmetric Capital Partners.
+- [The future](#the-future-faster-development-and-transition-to-non-profit-governance): faster development and the path to non-profit governance.
+
+[What's new in v6.0](#whats-new-in-v60):
+- Private message routing — now enabled by default.
+- [New chat experience](#new-chat-experience):
+  - connect to your friends faster.
+  - [new reachable interface](#new-reachable-interface).
+  - archive contacts to chat later.
+  - new way to start chat.
+  - [moderate like a pro](#moderate-like-a-pro): delete many messages at once.
+  - new chat themes<sup>*</sup>
+  - increase font size<sup>**</sup>.
+- [New media options](#new-media-options):
+  - play from the chat list.
+  - blur for better privacy.
+  - [share from other apps](#share-from-other-apps)<sup>*</sup>.
+- [Improved networking and reduced battery usage](#improved-networking-and-reduced-battery-usage)
+
+\* New for iOS app.
+
+\*\* Android and desktop apps.
+
+## SimpleX Chat: vision and funding 2.0
+
+### The past: investment from Village Global
+
+Last year [we announced](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html#how-is-it-funded-and-what-is-the-business-model) pre-seed funding from several angel investors and Village Global. Some of our users were very excited that we have funds to continue developing SimpleX network. But as some of Village Global LPs (Limited Partners) are [the founders of very large technology companies](https://www.villageglobal.vc), some of our users were worried about any negative influence this investment might have on the project.
+
+[Ben Casnocha](https://www.villageglobal.vc/team/ben-casnocha), the founder and general partner of Village Global, commented on their investment: 
+
+> I believe in SimpleX Chat vision and team’s ability to execute it. The growing number of Internet users who demand privacy of their data and contacts will make SimpleX Chat profitable, which is critically important for any sustainable organization.
+>
+> We are fortunate to have LPs who founded many iconic Internet ventures. But they don’t have any influence on the 400+ companies we invested in. They are financial investors in our fund and exert no control or influence on any of the underlying portfolio companies.
+>
+> What's more, we believe that founders should lead their ventures, as it yields better results – our investment in SimpleX Chat has no control provisions. We are happy to help, but we don’t control any decisions nor have a board seat. Evgeny runs the company independently.
+
+Ben, thank you for believing in our vision – without it SimpleX Chat would simply not exist, as most other investors at the time did not believe that privacy could ever escape the niche of privacy enthusiasts – and we already see the first signs of it happening. 
+
+### The present: announcing the investment from Jack Dorsey and Asymmetric
+
+The Android app recently hit [100,000 downloads on Google Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app), and our users naturally ask for improved reliability, privacy, security, better user experience and design – all at the same time, and as soon as possible. This requires more funding.
+
+We are very happy to announce that we now have funds to move faster – we raised a $1.3 million pre-seed round led by [Jack Dorsey](https://en.wikipedia.org/wiki/Jack_Dorsey), with participation of [Asymmetric Capital Partners](https://www.acp.vc) (ACP) VC fund. 
+
+When Jack discovered SimpleX Chat last year, he [posted on Twitter](https://x.com/jack/status/1661681076983529479): 
+
+> Better than Signal? Looks promising.
+> A few bugs and UX issues but great foundation. Love that it’s public domain.
+
+And [on Nostr](https://primal.net/e/note1txz9xmmc456kwcg7zrsrtqrhn7as29ptuz0qulu452k8n85hsshqq6uh6q): 
+
+> A full day with @SimpleX Chat. Solid overall. TestFlight is not recommended. There are some scaling issues today. And not the most intuitive onboarding for everyone. Name still reminds everyone of herpes. All fixable. It’s fast and doesn’t require a phone number or email and I do believe people will eventually see the value of that. Finally, some competition for Signal, and in a permissionless way. And def a solid path so apps don’t have to build their own DM experiences.
+
+Jack, we are super lucky to have your support and investment – thank you for believing in our ability to build a better messaging network! It is a hard work, and we’ve made a lot of progress since your note was written, and a lot of work is ongoing! 
+
+The ACP investment is strategically important – it is a fund that only invests in B2B startups, and SimpleX Chat currently is mostly used by individual users. Making a private communication network sustainable requires its adoption by businesses, and we already see a growing usage by the small teams. 
+
+[Rob Biederman](https://www.acp.vc/team/rob-biederman) and [Sam Clayman](https://www.acp.vc/team/sam), the partners of ACP, commented: 
+
+> We believe that SimpleX Chat network can grow into a de facto Internet standard for private and secure communications for both businesses and individual users, unifying instant and email-like messaging into a single product.
+>
+> Emails no longer provide privacy and security that businesses require, particularly given the emerging threat of AI-led phishing and social engineering attacks. We look forward to SimpleX network providing a secure alternative.
+
+I was lucky to have met Rob, Sam and the ACP team when I was presenting SimpleX Chat in London – thank you all for your support and believing that the future of communication requires a single product, both for businesses and individual users. 
+
+### The future: faster development and the path to non-profit governance
+
+Jack Dorsey and ACP support enable us to make huge product improvements, thanks to a bigger team, and provide us with medium-term funding to get to the next stage of product and business evolution. Like with Village Global, this is a financial investment, without control or board seat provisions – so the users can be certain that SimpleX remains true to our vision of privacy first communication network.
+
+We already added two great engineers to the team and are about to hire a UX/UI designer.
+
+[Trail of Bits](https://www.trailofbits.com/about/) has just completed the protocols design security review and will be doing implementation security review in the end of the year. We will publish the first report soon.
+
+This year we will launch group improvements that we presented in the [live-stream last year](https://www.youtube.com/watch?v=7yjQFmhAftE). While the main problem explained in this video was solved with the current design, the issue of group scalability remains – to send a message to a group your client needs to send it to each member, creating substantial traffic. 
+
+We will also launch long-form email-like messaging over SimpleX network this year, together with optional short public addresses that show profile you are connecting to before the connection – this is important for any public users and businesses.
+
+The last but not the least, we started the work with [Heather Meeker](https://www.techlawpartners.com/heather), a great legal expert on intellectual property matters and one of the earliest advocates of the open-source software development in businesses, to setup open-source governance model, to some extent similar to how Matrix did it. We believe, and our investors agree, that it would both increase the company value and also create more value for the users community.
+
+## What's new in v6.0
+
+v6.0 is one of our biggest releases ever, with a lot of focus on UX and stability improvements, and the new features the users asked for. 
+
+The private message routing [we announced before](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) is now enabled for all users by default – it protects users IP addresses and sessions from the destination servers.
+
+### New chat experience
+
+#### Connect to your friends faster 
+
+This version includes messaging protocol improvements that reduce twice the number of messages required for two users to connect. Not only it means connecting faster and using less traffic, this change allows to start sending messages sooner, so you would see "connecting" in the list of the chats for a much shorter time than before.
+
+It will be improved further in the next version: you will be able to send messages straight after using the invitation link, without waiting for your contact to be online.
+
+#### New reachable interface
+
+<img src="./images/20240814-reachable.png" width="288" class="float-to-right">
+
+Like with the most innovative mobile browsers (e.g., Safari and Firefox), SimpleX Chat users now can use the app with one hand by moving the toolbar and search bar to the bottom of the screen, and ordering the chats with the most recent conversations in the bottom too, where they can be more easily reached on a mobile screen. 
+
+This layout is enabled by default, and you can disable it right from the list of chats when you install the new version if you prefer to use conventional UI.
+
+Give it a try – our experience is that that after less than a day of using it, it starts feeling as the only right way. You can always toggle it in the Appearance settings.
+
+#### Archive contacts to chat later
+
+<img src="./images/20240814-delete-contact-2.png" width="288" class="float-to-right">   <img src="./images/20240814-delete-contact-1.png" width="288" class="float-to-right">
+
+Now you have two new options when deleting a conversation:
+- only delete conversation, and archive contact. We will add archiving conversation without clearing it in the next version, as some users of our beta version asked.
+- delete contact but keep the conversation.
+
+Also, deleting a contact now requires double confirmation, so you are less likely to delete the contact accidentally. This deletion is irreversible, and the only way to re-connect would be using a new link.
+
+#### New way to start chat
+
+<img src="./images/20240814-new-message.png" width="288" class="float-to-right">
+
+When you tap pencil button, you will see a large *New message* sheet, that adds new functions to the options you had before.
+
+Old options:
+- *Add contact* to create a new 1-time invitation link,
+- *Scan / paste link*: to use the link you received. It can be 1-time invitation, a public SimpleX address, or a link to join the group.
+- *Create group*
+
+New options:
+- Open archived chats.
+- Accept pending contact requests.
+- Connect to preset public addresses (we will add an option to add your own addresses here too).
+- Search for your contacts.
+
+#### New chat themes
+
+We released the new themes [for Android and desktop apps](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) in the previous version, and now they are available for iOS too.
+
+You can set different themes for different chat profiles you have, and for different conversations – it can help avoid mistakes about which conversation you are in.
+
+Also, these themes are compatible between platforms, so you can import the theme created on Android into iOS app and vice versa.
+
+#### Moderate like a pro
+
+<img src="./images/20240814-delete-messages.png" width="288" class="float-to-right">
+
+As much as we disagree with the attacks on the freedom of speech on the society level – all people must be able to express their opinions – we also believe that the small community owners should have full control over which content is allowed and which is not. But as communities grow, bad actors begin to join in order to disrupt, subvert and troll the conversations. So, the moderation tools are critical for small public communities to thrive.
+
+SimpleX Chat already has several moderation tools available for community owners:
+- Moderate individual messages.
+- Set the default role of the new members to "observer" — they won't be able to send messages until you allow it. In addition to that, by enabling default messages for admins and owners only you can reach out to the new members and ask some questions before allowing to send messages.
+- Block messages of a member for yourself only.
+- Block a member for all other members — only admins and group owners can do that.
+
+With this version you can now select multiple messages at once and delete or moderate them, depending on your role in the community. The current version limits the number of messages that can be deleted to 20 — this limit will be increased to 200 messages in the next version.
+
+Also, this version makes profile images of the blocked members blurred, to prevent the abuse via inappropriate profile images.
+
+#### Increase font size
+
+Android and desktop apps now allow to increase font size inside the app, without changing the system settings. Desktop app also allows to zoom the whole screen — it can be helpful on some systems with a limited support of high density displays.
+
+These settings can be changed via Appearance settings.
+
+### New media options
+
+#### Play from the chat list
+
+<img src="./images/20240814-play.png" width="288" class="float-to-right">
+
+Now you can interact with the media directly from the list of the chats.
+
+This is very convenient – when somebody sends you a voice message or a video, they can be played directly from the list of chats, without opening a conversation. Similarly, an image can be opened, a file can be saved, and the link with preview can be opened in the browser.
+
+And, in some circumstances, this is also more private, as you can interact with the media, without opening the whole conversation.
+
+We will add the option to return missed calls from the chat list in the next version.
+
+#### Blur for better privacy
+
+You can set all images and videos to blur in your app, and unblur them on tap (or on hover in desktop app). The blur level can be set in Privacy and security settings.
+
+#### Share from other apps
+
+<img src="./images/20240814-share.png" width="288" class="float-to-right">
+
+Not much to brag about, as most iOS messaging apps allow it, and users expected it to be possible since the beginning.
+
+But iOS makes it much harder to develop the capability to share into the app than Android, so it's only in this version you can share images, videos, files and links into SimpleX Chat from other apps.
+
+### Improved networking and reduced battery usage
+
+This version includes the statistics of how your app communicates with all servers when sending and receiving messages and files. This information also includes the status of connection to all servers from which you receive messages — whether the connection is authorized to push messages from server to your device, and the share of these active connections.
+
+Please note, that when you send a message to a group, your app has to send it to each member separately, so sent message statistics account for that — it may seem to be quite a large number if you actively participate in some large groups. Also, message counts not only include visible messages you receive and send, but also any service messages, reactions, message updates, message deletions, etc. — this is the correct reflection of how much traffic your app uses.
+
+This information is only available to your device, we do NOT collect this information, even in the aggregate form.
+
+While the main reason we added this information is to reduce traffic and battery usage, to be able to identify any cases of high traffic, this version already reduced a lot battery and traffic usage, as reported by several beta-version users.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+You might ask: *Why do you need donations if you've just raised the investment?*
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
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diff --git a/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md b/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md
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+# SimpleX network: security review of protocols design by Trail of Bits, v6.1 released with better calls and user experience.
+
+**Published:** Oct 14, 2024
+
+[New security audit](#simplex-cryptographic-design-review-by-trail-of-bits):
+- [review findings](#review-findings-our-comments-and-improvements), our comments and improvements.
+- [next](#next-security-audit-in-2025): security audit in early 2025.
+
+[What's new in v6.1](#whats-new-in-v61):
+- [better calls](#better-calls).
+- [better iOS notifications](#better-ios-notifications).
+- [better user experience](#better-user-experience).
+
+## SimpleX cryptographic design review by Trail of Bits
+
+<img src="./images/20221108-trail-of-bits.jpg" width=240 class="float-to-right">
+
+It's been almost two years since Trail of Bits did the first security assessment of SimpleX Chat.
+
+Since then SimpleX Chat grew a lot, both in the number of users and in its functionality. We added XFTP — a protocol for sending files, — and XRCP — the protocol for using a mobile app profile from a desktop app. Messaging protocols also evolved a lot, adding private message routing and quantum resistant encryption.
+
+Trail of Bits reviewed the design of protocols used in SimpleX network and applications in July 2024. Even though there are no critical issues, we made some security improvements based on this report.
+
+[Trail of Bits](https://www.trailofbits.com/about) is a US based security and technology consultancy whose clients include big tech companies, governmental agencies and major blockchain projects. Its engineers reviewed the cryptographic design of the protocols used in SimpleX network and applications over a week:
+- SimpleX Messaging Protocol (SMP), including a formal verification of currently used message queue negotiation protocol,
+- the SMP agent protocol,
+- the push notification system,
+- the file transfer protocol (XFTP),
+- the remote control protocol (XRCP),
+- and the chat protocol.
+
+There are 3 medium and 1 low severity findings, all of which require a high difficulty attack to exploit — the attacker would need to have a privileged access to the system, may need to know complex technical details, or must discover other weaknesses to exploit them. Additionally, there are 3 informational findings.
+
+3 of these issues are improved in v6.1, and the remaining issues are accepted. Below we are commenting on these findings in detail, and also on the released improvements. 
+
+The full cryptographic design review is available [here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf).
+
+We are very thankful to Trail of Bits and their engineers for their work identifying these issues and helping us make SimpleX Chat more secure.
+
+### Review findings, our comments and improvements
+
+#### Protocols specifications (informational)
+
+The review finding #1 is that the protocols specification is informal. We addressed [reported](https://github.com/simplex-chat/simplexmq/commit/7b6c86c6c1093cdae5ad2ee566655828076bc25c) [inconsistencies](https://github.com/simplex-chat/simplex-chat/commit/1cb3c25478db0f2a42c943f7469f5f9f75752a27), and we accept that we need to improve specification beyond verbose descriptions and ABNF syntax specification, and add algebraic notations and sequence diagrams. Having said that, the current specification correctly describes the implemented protocol, without any contradictions.
+
+#### User-correlating attacks via introduced latency or via GET command of messaging protocol (medium and low severity)
+
+These two findings #7 and #2 of the report relate to the attacks confirming that two known users communicate via observing their internet traffic.
+
+The first attack is possible for a party that can introduce the latency in the network traffic. This attacker has to control some network node that passes the traffic of the sender — for example, it could be the sender's ISP, VPN provider, Tor entry node operator, the operator of the forwarding SMP server or a server hosting provider, etc. Such attacker can correlate delays in sender's traffic and the suspected recipient's traffic to confirm that they communicate.
+
+The second attack relates to GET command used by iOS clients receiving notifications — depending on whether the server has the message, there will be a different number of packets sent, allowing the observer to determine if there was the message. While this comment is correct, in practice iOS clients only send GET commands when they receive notification, which also happens only when there is a message on the server, so in absolute majority of cases the number of packets will be the same.
+
+These are not new findings — this type of attacks is covered in [threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#a-passive-adversary-able-to-monitor-a-set-of-senders-and-recipients): _a passive adversary able to monitor a set of senders and recipients **can** perform traffic correlation attacks against senders and recipients and correlate senders and recipients within the monitored set, frustrated by the number of users on the servers_.
+
+As threat model states, this attack is more likely to be successful with the less busy servers, and also for the users with few connections.
+
+The recommendation of the review is to add optional randomized latency to message delivery that would reduce the opportunities for traffic correlation attacks — we consider adding it in the future.
+
+#### A compromised transport protocol allows more efficient correlation attacks (medium severity)
+
+The finding #3 is about the incorrect statement in threat model for SMP and XFTP protocols: _a passive adversary, able to monitor a set of senders and recipients, **cannot**, even in case of a compromised transport protocol perform traffic correlation attacks with any increase in efficiency over a non-compromised transport protocol_.
+
+For protocols prior to v6.1 it is only partially correct, as responses to the commands that create a messaging queue or a file chunk include the identifiers both for senders and for the recipients, so if any observers were to compromise transport protocol (TLS) and record these identifiers, then they were able to correlate message senders with the recipients (and file recipients with the file senders).
+
+The solution to make this correlation impossible even in case of compromised TLS is to encrypt these identifiers, as proposed in the review, or, better, encrypt the whole transmission inside TLS.
+
+However unlikely is TLS being compromised, we added additional [transport encryption layer in SMP protocol](https://github.com/simplex-chat/simplexmq/pull/1317/files), where it can be more important, and we are going to add the same layer of encryption in XFTP protocol later, where we [amended the threat model](https://github.com/simplex-chat/simplexmq/commit/7b6c86c6c1093cdae5ad2ee566655828076bc25c).
+
+#### XRCP protocol recommendations (informational)
+
+XRCP protocol is used for connecting desktop and mobile. There are two findings in the review:
+
+- SHA256 was used as a KDF in XRCP (#4).
+- there was no forward secrecy or break-in recovery between sessions (#5).
+
+SHA256 is now [replaced with SHA3-256](https://github.com/simplex-chat/simplexmq/pull/1302/files), as was [recommended](https://www.ietf.org/archive/id/draft-josefsson-ntruprime-hybrid-01.html) by the internet draft about hybrid key agreement that XRCP uses.
+
+Even though XRCP sessions are short lived, and usually the connection happens over local network, we added forward secrecy to XRCP sessions [here](https://github.com/simplex-chat/simplexmq/pull/1328/files) and [here](https://github.com/simplex-chat/simplex-chat/pull/4926/files) — each request from desktop app to mobile app is now encrypted with a new key derived from chain ratchets. This improves security of this connection.
+
+We believe that it is unnecessary to have in-session break-in recovery in XRCP protocol, as there is break-in recovery between the sessions.
+
+#### Device compromise can be hidden in some scenarios (medium)
+
+The finding #6 in the report is about an attacker who was not only able to break into the device and get a copy of the database, which would be mitigated by break-in recovery in [double ratchet protocol](https://simplex.chat/docs/glossary.md#double-ratchet-algorithm), but also was able to modify the state of the app database and to substitute the addresses and cryptographic keys of the messaging queues used with some contact with other message queues that the attacker controls.
+
+Even though this is a very hard attack, if successful, it would allow the attacker intercepting all messages with this contact.
+
+Effectively, it is a [man-in-the-middle attack](https://simplex.chat/docs/glossary.md#man-in-the-middle-attack), where an intermediary is inserted via the app database modification. Such attack can be mitigated by periodic verification of security codes. Although, the attacker who was able to modify the state of the device, could have also modified the app itself, making it show the same security code as the compromised contact has, thus avoiding detection.
+
+We accept that such an attack is possible, and we don't believe there is any viable defense against the attacker who can modify the device state. We may consider adding the measures to validate the database integrity, but they may be ineffective in case the app and/or operating system are compromised.
+
+### Next: security audit in 2025
+
+We are planning the implementation security assessment with Trail of Bits in the beginning of 2025. It will be a twice bigger assessment than we did in 2022 — it will cover both the core of the app and the handling of cryptographic secrets in the mobile applications.
+
+## What's new in v6.1
+
+This release has many user experience and stability improvements.
+
+### Better calls
+
+<img src="./images/20241014-calls.png" width="288" class="float-to-right">
+
+This release improves reliability and usability of the calls. Now you can enable the camera and share the screen from the desktop app even if the call started as a voice call. We've also fixed several issues that prevented calls from connecting.
+
+This is a substantial change, and some issues may have been introduced - please report them.
+
+We will be further improving the calls interface in the app in the next versions.
+
+### Better iOS notifications
+
+iOS notifications were added [more than 2 years ago](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md), based on this [system design](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md). Until recently we made almost no improvements to them. As the number of iOS users is growing, their reliability is insufficient. In addition to that, once we started the work on improving them, we have found several important issues, one of which was introduced recently, when we improved the speed of creating new connections.
+
+This release fixes many important issues with iOS notifications delivery in iOS app, improves app performance and reduces traffic required to manage notifications.
+
+We also fixed several notification server issues, made change that almost completely prevents losing notifications when notification servers are restarted, and added real-time monitoring to diagnose any issues with iOS notifications delivery.
+
+This work is not over – iOS notifications in a decentralized network are complex and require more work. We will be further improving both client apps and servers to make their delivery stable.
+
+
+### Better user experience
+
+#### New conversation layout and customizable messages
+
+<img src="./images/20241014-messages.png" width="288" class="float-to-right">
+
+Messages are now grouped when they are sent sequentially, with less than 60 seconds between them. We also made message shapes configurable, and separated the messages in different days. When you scroll conversation quickly, there will be a floating date indication, allowing to find messages faster.
+
+#### Improved switching between user profiles
+
+<img src="./images/20241014-profiles2.png" width="288" class="float-to-right"> <img src="./images/20241014-profiles1.png" width="288" class="float-to-right">
+
+Another improvement relates to switching between chat profiles. Previously, when you added multiple chat profiles to the app, there were two problems:
+- you had to tap twice to get to some important functions in the app,
+- anybody who could see your screen, could also see all your chat profiles.
+
+We changed this design by making important functions available after tapping profile image once, and by only showing the previously used profile image to switch to it quickly, while switching to other profiles now requires scrolling to them or opening *Your chat profiles* screen.
+
+You also can switch chat profile when creating a one-time invitation link.
+
+#### Faster deletion, moderation and forwarding of messages
+
+<img src="./images/20241014-forward.png" width="288" class="float-to-right">
+
+You now can forward multiple messages at once - up to 20. If you are forwarding messages with files or media, and they were not received, the app will offer you to download them, and it will also allow forwarding messages without files. These messages will be "packed" into the smallest number of sent messages as possible. If there are no images and messages are not too large, it will be just one sent message containing all forwarded messages.
+
+The previous version allowed deleting and moderating multiple messages. As most users now upgraded the app, we increased the maximum number of messages that can be deleted or moderated to 200 messages - in most cases all these deletions will be packed into one sent message.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/tree/master#help-us-with-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20241016-wired-attack-on-privacy.html b/blog/20241016-wired-attack-on-privacy.html
index 73ad597c93..c5efea8899 100644
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     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20241016-wired-attack-on-privacy.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20241016-wired-attack-on-privacy.md b/blog/20241016-wired-attack-on-privacy.md
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+# Wired’s Attack on Privacy
+
+**Published:** Oct 16, 2024
+
+<img src="./images/20241016-wired-privacy.jpg" width="330" class="float-to-right">
+
+The [Wired article](https://www.wired.com/story/neo-nazis-flee-telegram-encrypted-app-simplex/) by David Gilbert focusing on neo-Nazis moving to SimpleX Chat following the Telegram's changes in privacy policy is biased and misleading. By cherry-picking information from [the report](https://www.isdglobal.org/digital_dispatches/neo-nazi-accelerationists-seek-new-digital-refuge-amid-looming-telegram-crackdown/) by the Institute for Strategic Dialogue (ISD), Wired fails to mention that SimpleX network design prioritizes privacy in order to protect human rights defenders, journalists, and everyday users who value their privacy — many people feel safer using SimpleX than non-private apps, being protected from strangers contacting them.
+
+Yes, privacy-focused SimpleX network offers encryption and anonymity — that’s the point. To paint this as problematic solely because of who may use such apps misses the broader, critical context.
+
+SimpleX’s true strength lies in protection of [users' metadata](https://simplex.chat/blog/20240416-dangers-of-metadata-in-messengers.md), which can reveal sensitive information about who is communicating, when, and how often. SimpleX protocols are designed to minimize metadata collection. For countless people, especially vulnerable groups, these features can be life-saving. Wired article ignores these essential protections, and overlooks the positive aspects of having such a unique design, as noted in the publication which [they link to](https://www.maargentino.com/is-telegrams-privacy-shift-driving-extremists-toward-simplex/):
+
+> *“SimpleX also has a significant advantage when it comes to protecting metadata — the information that can reveal who you’re talking to, when, and how often. SimpleX is designed with privacy at its core, minimizing the amount of metadata collected and ensuring that any temporary data necessary for functionality is not retained or linked to identifiable users.”*
+
+Both publications referenced by Wired also explore how SimpleX design actually hinders extremist groups from spreading propaganda or building large networks. SimpleX design restricts message visibility and file retention, making it far from ideal for those looking to coordinate large networks. Yet these important qualities are ignored by Wired in favor of fear-mongering about encryption — an argument we've seen before when apps like Signal [faced similar treatment](https://foreignpolicy.com/2021/03/13/telegram-signal-apps-right-wing-extremism-islamic-state-terrorism-violence-europol-encrypted/). Ironically, Wired just a month earlier encouraged its readers to [adopt encrypted messaging apps](https://www.wired.com/story/gadget-lab-podcast-657/), making its current stance even more contradictory.
+
+The vilification of apps that offer critically important privacy, anonymity, and encryption must stop. That a small share of users may abuse these tools doesn’t justify broad criticism. Additionally, the lobbying for client-side scanning, which Wired’s article seems to indirectly endorse, is not only dangerous but goes against fundamental principles of free speech and personal security. We strongly oppose the use of private communications for any kind of monitoring, including AI training, which would undermine the very trust encryption is designed to build.
+
+It’s alarming to see Wired not only criticize SimpleX for its strong privacy protections but also subtly blame the European Court of Human Rights for [upholding basic human rights](https://www.theregister.com/2024/02/15/echr_backdoor_encryption/) by rejecting laws that would force encrypted apps to scan and hand over private messages before encryption. Wired writes:
+
+> *…European Court of Human Rights decision in February of this year ruled that forcing encrypted messaging apps to provide a backdoor to law enforcement was illegal. This decision undermined the EU’s controversial proposal that would potentially force encrypted messaging apps to scan all user content for identifiers of child sexual abuse material.*
+
+This commentary is both inappropriate and misguided — it plays into the hands of anti-privacy lobbyists attempting to criminalize access to private communications. Framing privacy and anonymity as tools for criminals ignores the reality that these protections are essential for millions of legitimate users, from activists to journalists, to ordinary citizens. Client-side scanning can't have any meaningful effect on reducing CSAM distribution, instead resulting in increase of crime and abuse when criminals get access to this data.
+
+We need to correct this narrative. The real danger lies not in protecting communication, but in failing to do so. Privacy apps like SimpleX are crucial, not just for those resisting mass surveillance, but for everyone who values the right to communicate without fear of their conversations being monitored or misused. This is a right we must defend and incorporate into law, [as we wrote before](https://simplex.chat/blog/20240704-future-of-privacy-enforcing-privacy-standards.md).
+
+Wired could have stood on the right side of this battle and helped normalize the demand for privacy, genuinely protecting people from criminals and from the exploitation of the increasingly AI-enabled mass surveillance. Instead they chose the path of spreading fear and uncertainty of encrypted messaging and tools that enable privacy and anonymity.
+
+Spreading misinformation about privacy and security undermines trust in the tools that protect us, making it easier to justify more invasive surveillance measures that chip away at our civil liberties.
+
+Wired did not respond to our request for comment.
diff --git a/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html b/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html
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--- a/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html
+++ b/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.md b/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.md
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+++ b/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.md
@@ -0,0 +1,136 @@
+# Servers operated by Flux — true privacy and decentralization for all users
+
+**Published:** Nov 25, 2024
+
+- [Welcome, Flux](#welcome-flux--the-new-servers-in-v62-beta1) — the new servers in v6.2-beta.1!
+- [What's the problem](#whats-the-problem)?
+- [Using two operators improves connection privacy](#using-two-operators-improves-connection-privacy).
+- [SimpleX decentralization](#simplex-decentralization-compared-with-matrix-session-and-tor) compared with Matrix, Session and Tor.
+- [What's next](#whats-next-for-simplex-network-decentralization) for SimpleX network decentralization?
+
+## Welcome, Flux – the new servers in v6.2-beta.1!
+
+<img src="./images/20241125-operators-1.png" width="288" class="float-to-right">
+
+[Flux](https://runonflux.com) is a decentralized cloud infrastructure that consists of user-operated nodes [1]. With this beta release all SimpleX Chat users can use pre-configured Flux servers to improve metadata privacy and decentralization.
+
+We are very grateful to [Daniel Keller](https://x.com/dak_flux), CEO and co-founder of Flux, for supporting SimpleX network, and betting on our vision of extreme decentralization of communication. Flux investing their infrastructure in our vision is a game changer for us and our users.
+
+Download new mobile and desktop SimpleX apps from [TestFlight](https://testflight.apple.com/join/DWuT2LQu) (iOS), [Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app), our [F-Droid repo](https://simplex.chat/fdroid/) or [GitHub](https://github.com/simplex-chat/simplex-chat/releases/tag/v6.2.0-beta.1).
+
+Read on to learn why it is important and how using several operators improves metadata privacy.
+
+## What's the problem?
+
+SimpleX network is fully decentralized, without any central component or bootstrap nodes — you could use your own servers from day one. While there is no full list of SimpleX network servers, we see many hundreds of servers in public groups.
+
+But a large number of SimpleX app users use the servers pre-configured in the app. Even though the app randomly chooses 4 servers in each connection to improve privacy and security, prior to v6.2 for these users the servers were operated by the same company — ourselves.
+
+Our open-source code that we are [legally bound to use](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md#legally-binding-transparency) doesn't provide any metadata that could be used to learn who connects to whom. But the privacy of users' connections still depends on us honouring our promises and [privacy policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md). Flux servers in the app improve that.
+
+## Using two operators improves connection privacy
+
+<img src="./images/20241125-operators-2.png" width="288" class="float-to-right">
+
+To ensure that the users' metadata from different servers cannot be combined to discover who talks to whom, the servers in each connection have to be operated by different independent organizations.
+
+Before this version the app was choosing servers randomly. Now, when both SimpleX Chat and Flux servers are enabled it will always choose servers of different operators in each connection to receive messages and for [private message routing](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md), increasing metadata privacy for all users.
+
+Flux servers are configured as opt-in, and the privacy policy and conditions of use that apply to Flux servers are the same as for SimpleX Chat servers, to make it simple for the users.
+
+To improve connection privacy by using Flux servers all you have to do is to enable Flux once the app offers it, or later, via Network & servers settings, and accept that the same conditions apply.
+
+<img src="./images/20241125-operators-3.png" width="330" class="float-to-left">
+
+By default, if both Flux and SimpleX servers are enabled in this version, you will be using SimpleX Chat servers to receive messages, Flux servers to forward messages to SimpleX Chat servers, and the servers of both to forward messages to unknown servers. We will enable Flux to receive messages by default a bit later, or you can change it now via settings.
+
+Any additional servers you add to app configuration are treated as belonging to another operator, so they will also be used to improve connection privacy, together with pre-configured servers, unless you disable them.
+
+## SimpleX decentralization compared with Matrix, Session and Tor
+
+SimpleX network decentralization model is different from other decentralized networks in several important aspects.
+
+| Communication network        | SimpleX | Matrix | Session | Tor-based |
+|:-----------------------------|:-------:|:------:|:-------:|:---------:|
+| Full decentralization        | ✅      | -      | -       | -         |
+| No user profile identity     | ✅      | -      | -       | -         |
+| Connection privacy           | ✅      | -      | ✅      | ✅        |
+| Server operator transparency | ✅      | ✅     | -       | -         |
+
+**Full decentralization**
+
+Fully decentralized networks do not have a central component, bootstrap nodes or any global shared state, like in cryptocurrency/blockchain-based communication networks. The presence of any central component or shared state introduces an attack vector that undermines privacy and security of the network.
+
+**No user profile identity**
+
+User profile identities, even if it is only a random number or a long-term key, undermine privacy of users connections, because in some cases they may allow network operators, observers and users to find out who talks to whom.
+
+Most communication networks rely on fixed user profile identities. It includes Matrix and communication networks with onion routing.
+
+SimpleX network design avoids the need for profile identities or keys, while still allowing optional long-term addresses for users and groups for convenience. It protects users from being discovered and approached by malicious parties, and many family users chose to use SimpleX with children because of it.
+
+**Connection privacy**
+
+SimpleX network has [private message routing](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) (2-hop onion routing) — it prevents server operators from discovering who connects to whom via network traffic metadata. Onion routing used in Tor-based messengers and in Session also hides it. But because neither Tor nor Session users have knowledge about who operates servers, in some cases the clients may connect via the servers controlled by one entity, that may learn the IP addresses of both parties.
+
+Statistically, if traffic metadata from 2% of onion network servers is available to an attacker, and the client chooses servers randomly, after about 1750 of such choices the probability of choosing attacker's servers as both entry and exit nodes, and connection privacy being compromised becomes over 50% [2].
+
+Matrix network does not provide connection privacy, as not only user identity exists, it is tied to a specific server that knows all user connections and a part of user's contacts connections. What is worse, Element — the most widely used Matrix app — offers the servers of only one organization to create an account, resulting in some degree of network centralization.
+
+**Server operator transparency**
+
+Operator transparency means that network users know who operates the servers they use.
+
+You may argue that when the operators are known, the servers data can be requested by the authorities. But such requests, in particular when multiple operators are used by all users, will follow a due legal process, and will not result in compromising the privacy of all users.
+
+With Tor and Session networks such legal process becomes impossible, and some users may see it as advantage. But nothing prevents the attackers, both criminal and corporate- or state-funded, to compromise the privacy of Tor or Session users by running many servers, or by purchasing traffic metadata from the existing server owners — there are no legal conditions that prohibit server owners of these networks to share or sell traffic data.
+
+Because of that, we see operator transparency in SimpleX network as a better trade-off for privacy of most users than operator anonymity provided by Session and Tor. You can see privacy of network participants as a zero sum game — for the end users to have it, server operators should be known.
+
+## What's next for SimpleX network decentralization
+
+SimpleX network is designed for extreme decentralization — not only users are distributed across network operators, as happens with federated networks, but each conversation will be relying on servers of 4-6 independent operators, and these operators will be regularly and automatically changed in the near future.
+
+We believe that the only viable commercial model is freemium — a small share of paying users, who have better service quality and additional features, sponsors free users. This model doesn't have downsides of exploitative "provide service, sell data" approaches, that technology monopolies practice, and it also doesn't have problems of cryptocurrency blockchains, that have shared and immutable state, and also have regulatory problems.
+
+To provide this extreme decentralization with freemium model we will create the system of payments allowing server operators to receive money for infrastructure certificates that will be used with any other participating network operators without compromising privacy of the paying users. You can read about this model [here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2024-04-26-commercial-model.md). We will be writing more about it as this development progresses.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/#please-support-us-with-your-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
+
+[1]: You can also to self-host your own SimpleX servers on [Flux decentralized cloud](https://home.runonflux.io/apps/marketplace?q=simplex).
+
+[2]: The probability of connection being de-anonymized and the number of random server choices follow this equation: `(1 - s ^ 2) ^ n = 1 - p`, where `s` is the share of attacker-controlled servers in the network, `n` is the number of random choices of entry and exit nodes for the circuit, and `p` is the probability of both entry and exit nodes, and the connection privacy being compromised. Substituting `0.02` (2%) for `s`, `0.5` (50%) for `p`, and solving this equation for `n` we obtain that `1733` random circuits have 50% probability of privacy being compromised.
+
+Also see [this presentation about Tor](https://ritter.vg/p/tor-v1.6.pdf), specifically the approximate calculations on page 76, and also [Tor project post](https://blog.torproject.org/announcing-vanguards-add-onion-services/) about the changes that made attack on hidden service anonymity harder, but still viable in case the it is used for a long time.
diff --git a/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html b/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html
index 2447c3e3a4..3261440de6 100644
--- a/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html
+++ b/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md b/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md
new file mode 100644
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--- /dev/null
+++ b/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md
@@ -0,0 +1,110 @@
+# SimpleX network: preset servers operated by Flux, business chats and more with v6.2 of the apps
+
+**Published:** Dec 10, 2024
+
+What's new in v6.2:
+
+- [SimpleX Chat and Flux](#simplex-chat-and-flux-improve-metadata-privacy-in-simplex-network) improve metadata privacy in SimpleX network.
+- [Business chats](#business-chats) to provide support from your business to users of SimpleX network.
+- [Better user experience](#better-user-experience): open on the first unread, jump to quoted messages, see who reacted.
+- [Improving notifications in iOS app](#improving-notifications-in-ios-app).
+
+## What's new in v6.2
+
+### SimpleX Chat and Flux improve metadata privacy in SimpleX network
+
+<img src="./images/20241210-operators-1.png" width=288 class="float-to-right"> <img src="./images/20241210-operators-2.png" width=288 class="float-to-right">
+
+SimpleX Chat and [Flux](https://runonflux.com) (Influx Technology Limited) made an agreement to include messaging and file servers operated by Flux into the app.
+
+SimpleX network is decentralized by design, but in the users of the previous app versions had to find other servers online or host servers themselves to use any other servers than operated by us.
+
+Now all users can choose between servers of two companies, use both of them, and continue using any other servers they host or available online.
+
+To use Flux servers enable them when the app offers it, or at any point later via Network & servers settings in the app.
+
+When both SimpleX Chat and Flux servers are enabled, the app will use servers of both operators in each connection to receive messages and for [private message routing](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md), increasing metadata privacy for all users.
+
+Read more about why SimpleX network benefits from multiple operators in [our previous post](https://simplex.chat/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.md).
+
+You can also read about our plan [how network operators will make money](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2024-04-26-commercial-model.md), while continuing to protect users privacy, based on network design rather than on trust to operators, and without any cryptocurrency emission.
+
+### Business chats
+
+<img src="./images/20241210-business.png" width=288 class="float-to-right">
+
+We use SimpleX Chat to provide support to SimpleX Chat users, and we also see some other companies offering SimpleX Chat as a support channel.
+
+One of the problem of providing support via general purpose messengers is that the customers don't see who they talk to, as they can in all dedicated support systems.
+
+It is not possible in most messengers, including SimpleX Chat prior to v6.2 - every new customer joins a one-to-one conversation, where the customers see that they talk to a company, not knowing who they talk to, and if it's a bot or a human.
+
+The new business chats in SimpleX Chat solve this problem: to use them enable the toggle under the contact address in your chat profile. It is safe to do, and you can always toggle it off, if needed - the address itself does not change.
+
+Once you do it, the app will be creating a new business chat with each connecting customer where multiple people can participate. Business chat is a hybrid of one-to-one and group conversation. In the list of chats you will see customer names and avatars, and the customer will see your business name and avatar, like with one-to-one conversations. But inside it works as a group, allowing customer to see who sent the message, and allowing you to add other participants from the business side, for delegation and escalation of customer questions.
+
+This can be done manually, or you can automate these conversations using bots that can answer some customer questions and then add a human to the conversation when appropriate or requested by the customer. We will be offering more bot-related features to the app and a simpler way to program bots very soon - watch our announcements.
+
+### Better user experience
+
+<img src="./images/20241210-reactions.png" width=288 class="float-to-right">
+
+**Chat navigation**
+
+This has been a long-standing complaint from the users: *why does the app opens conversations on the last message, and not on the first unread message*?
+
+Android and desktop apps now open the chat on the first unread message. It will soon be done in the iOS app too.
+
+Also, the app can scroll to the replied message anywhere in the conversation (when you tap it), even if it was sent a very long time ago.
+
+**See who reacted!**
+
+This is a small but important change - you can now see who reacted to your messages!
+
+### Improving notifications in iOS app
+
+iOS notifications in a decentralized network is a complex problem. We [support iOS notifications](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md#ios-notifications-require-a-server) from early versions of the app, focussing on preserving privacy as much as possible. But the reliability of notifications was not good enough.
+
+We solved several problems of notification delivery in this release:
+- messaging servers no longer lose notifications while notification servers are restarted.
+- Apple can drop notifications while your device is offline - about 15-20% of notifications are dropped because of it. The servers and the new version of the app work around this problem by delivering several last notifications, to show notifications correctly even when Apple drops them.
+
+With these changes the iOS notifications remained as private and secure as before. The notifications only contain metadata, without the actual messages, and even the metadata is end-to-end encrypted between SimpleX notification servers and the client device, inaccessible to Apple push notification servers.
+
+There are two remaining problems we will solve soon:
+- iOS only allows to use 25mb of device memory when processing notifications in the background. This limit didn't change for many years, and it is challenging for decentralized design. If the app uses more memory, iOS kills it and the notification is not shown – approximately 10% of notifications can be lost because of that.
+- for notifications to work, the app communicates with the notification server. If the user puts the app in background too quickly, the app may fail to enable notification for the new contacts. We plan to change clients and servers to delegate this task to messaging servers, to remove the need for this additional communication entirely, without any impact on privacy and security. This will happen early next year.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/#please-support-us-with-your-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.html b/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.md b/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.md
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+# Oppose digital IDs – they break the law and lead to mass scale surveillance
+
+**Published:** Dec 18, 2024
+
+<img src="./images/20241218-pub.jpg" width="330" class="float-to-right">
+
+Starting next year, the UK government plans to introduce [digital ID cards](https://www.telegraph.co.uk/politics/2024/12/08/digital-id-to-be-introduced-for-pubs-and-clubs/) for the young people to prove their age when visiting pubs. While officials claim this system will remain optional, it's part of a broader government initiative to move more state functions online so that people can prove their identity for everything from paying taxes to opening a bank account using the government-backed app. This will be a step toward a society where every pub visit, purchase, and social interaction becomes a permanent digital record linked to a government-issued ID – a step to normalizing mass surveillance at scale.
+
+Digital IDs are promoted as a way to fight law violations, and some politicians support them as [a way to tackle illegal immigration](https://www.telegraph.co.uk/politics/2024/07/10/id-cards-inevitable-tackle-immigration-lord-blunkett-labour/). But digital IDs themselves break the law. Article 8 of the European Convention of Human Rights says: “Everyone has the right to respect for his private and family life”. It means that not only our right to privacy is enshrined in the law, but the right to have our privacy respected is also part of the law. Asking to present a digital ID when visiting a pub, even if it is optional, disrespects our privacy, and is therefore illegal.
+
+Digital IDs would not stop people who decide to break laws. Pubs already can refuse to serve alcohol to young people and require the ID in case the age is in doubt. And illegal immigration can also be reduced without any digital IDs. But introducing digital IDs and collecting our actions, names and locations in one government-controlled database will result in making this information easier to access for criminals, and being exploited for financial and identity crimes.
+
+What starts as a "convenient option" is likely to end as a mandatory requirement. The digital ID systems being pushed by governments and corporations aren't about making our lives easier. They're about tracking, monitoring, and controlling every move we make. And we can see [where this road leads in China](https://www.wired.com/story/china-social-credit-system-explained/), when IDs and social scores created for convenience are used to prevent access to basic services and bank accounts as a punishment for legal social media posts that the government disagrees with. What started as a convenience, is now trialed [to track the duration of public toilet visits](https://www.thesun.ie/news/13154812/china-installs-toilet-timers-to-broadcast-time-spent/).
+
+The United Kingdom is a democratic country, and the law protects our right to privacy and freedom of speech. If we accept digital IDs as something required for simple things, like buying a drink, it leaves the door wide open to a range of privacy violations.
+
+We call on everyone to oppose the digital ID systems. Do not use them. Do not install these systems in your pub, for as long as it is not legally required. Support local businesses that don’t use them. Protect your privacy and freedom by using software that respects them. Demand that your privacy is respected, as required by law.
+
+To make your voice heard, email your MP expressing your rejection of digital IDs as a violation of European Convention of Human Rights in three simple steps:
+
+1. **Copy the text below** or [click this link](mailto:?subject=Please%20oppose%20the%20plan%20for%20Digital%20IDs&body=Dear%20%E2%80%A6%2C%0A%0AI%20object%20to%20the%20introduction%20of%20digital%20IDs%20in%20pubs%20or%20any%20other%20public%20places%20for%20these%20reasons%3A%0A%0A1.%20It%20violates%20the%20European%20Convention%20of%20Human%20Rights%2C%20article%208%3A%20%E2%80%9CEveryone%20has%20the%20right%20to%20respect%20for%20his%20private%20and%20family%20life%E2%80%9D%20(https%3A%2F%2Ffra.europa.eu%2Fen%2Flaw-reference%2Feuropean-convention-human-rights-article-8-0).%0AAsking%20to%20present%20digital%20IDs%20when%20proof%20of%20identity%20is%20not%20legally%20required%2C%20even%20if%20it%20is%20optional%2C%20disrespects%20our%20privacy%2C%20and%20is%20therefore%20illegal.%0A%0A2.%20It%20will%20not%20be%20an%20effective%20measure%20in%20reducing%20the%20violations%20of%20the%20law.%20People%20who%20want%20to%20circumvent%20it%2C%20will%20find%20a%20way.%0A%0A3.%20It%20will%20increase%20crime%2C%20because%20combining%20a%20large%20amount%20of%20private%20information%20in%20a%20single%20system%20increases%20the%20risks%20of%20this%20information%20becoming%20available%20to%20criminals%2C%20who%20will%20exploit%20it%20for%20financial%20crimes%20and%20identity%20theft.%0A%0AI%20kindly%20ask%20you%20to%20oppose%20this%20plan%2C%20both%20publicly%20and%20during%20any%20discussions%20in%20the%20UK%20Parliament.%0A%0ASincerely%20yours%2C%0A%E2%80%A6) to copy it into email app:
+
+*Dear …,*
+
+*I object to the introduction of digital IDs in pubs or any other public places for these reasons:*
+
+1. *It violates the European Convention of Human Rights, article 8: “Everyone has the right to respect for his private and family life” (https://fra.europa.eu/en/law-reference/european-convention-human-rights-article-8-0).*
+*Asking to present digital IDs when proof of identity is not legally required, even if it is optional, disrespects our privacy, and is therefore illegal.*
+2. *It will not be an effective measure in reducing the violations of the law. People who want to circumvent it, will find a way.*
+3. *It will increase crime, because combining a large amount of private information in a single system increases the risks of this information becoming available to criminals, who will exploit it for financial crimes and identity theft.*
+
+*I kindly ask you to oppose this plan, both publicly and during any discussions in the UK Parliament.*
+
+*Sincerely yours,*
+*…*
+
+2. [**Find the email address of your MP**](https://members.parliament.uk/members/Commons) and copy it to the email.
+
+3. Fill in the blanks, edit the text if needed, and **send it**!
+
+Public opposition changed government decisions in many cases.
+
+It is your opportunity to tell the government which country you want to live in — please use it!
diff --git a/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.html b/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md b/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md
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+# SimpleX network: large groups and privacy-preserving content moderation
+
+**Published:** Jan 14, 2025
+
+<img src="./images/20250114-locked-books.jpg" width="345" class="float-to-right">
+
+Many people believe that it is impossible to moderate and prevent abuse in end-to-end encrypted conversations. This belief is incorrect — there is a way to prevent abuse and distribution of illegal content without any compromises to users' privacy and security of end-to-end encryption.
+
+Anti-privacy lobbyists use this incorrect belief to advocate for scanning of private communications, which not only would fail to prevent abuse, but would make it worse — because our private data will become available to criminals.
+
+So it's very important to understand how privacy preserving content moderation works, and educate the politicians who you voted for, and who is currently in the office, that we do not need to compromise privacy and security in any way to substantially reduce online crime and abuse.
+
+This post answers these questions:
+- Why [large groups on SimpleX network](#large-groups-on-simplex-network) don't work well?
+- How do we plan to [make them scale](#can-large-groups-scale)?
+- How do [group owners prevent abuse](#preventing-abuse-with-anonymous-participation) when people participate anonymously?
+- How do server operators [prevent abuse of their servers](#preventing-server-abuse-without-compromising-e2e-encryption) and [how these measures will evolve](#privacy-preserving-content-moderation) without any compromises to privacy and end-to-end encryption?
+- Which [privacy and security improvements](#privacy-and-security-improvements-we-plan-this-year) we plan this year?
+
+## Large groups on SimpleX network
+
+When we designed groups, we expected them to be used primarily for small groups where people know each other, with not more than 100 or so members.
+
+But we learnt that people want to participate in public discussions remaining anonymous — it protects their freedom of speech. As an experiment, we are curating a small [directory of groups](https://simplex.chat/docs/directory.md) that currently has almost 400 public groups, with the largest ones having thousands of members. You can connect to this experimental directory via [SimpleX chat address](https://simplex.chat/contact#/?v=2-4&smp=smp%3A%2F%2Fu2dS9sG8nMNURyZwqASV4yROM28Er0luVTx5X1CsMrU%3D%40smp4.simplex.im%2FeXSPwqTkKyDO3px4fLf1wx3MvPdjdLW3%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEAaiv6MkMH44L2TcYrt_CsX3ZvM11WgbMEUn0hkIKTOho%253D%26srv%3Do5vmywmrnaxalvz6wi3zicyftgio6psuvyniis6gco6bp6ekl4cqj4id.onion).
+
+## Can large groups scale?
+
+Currently the groups are fully decentralized, and every time you send the message to some group your client has to send it to each group member, which is very costly for traffic and battery in large groups.
+
+We are currently working on the new group architecture when dedicated group members that run their clients on the server or on desktop with good internet connection will re-broadcast messages to all members — these members are "super-peers".
+
+We will be offering pre-configured super-peers via the app, and you will be able to use your own super-peers, in case you are hosting a large private group, and to have a better control and ownership of the group — e.g., if we decide to remove our super peer from the group, it will continue to function thanks to your super-peer re-broadcasting messages.
+
+This new design improves both privacy of group participation and censorship resistance of the groups, and also makes abusing the group harder.
+
+## Preventing abuse with anonymous participation
+
+All public discussions are abused by spammers and trolls, whether anonymous or not. We have been evolving ability of group owners to moderate conversations by allowing to remove inappropriate and off-topic messages, to block members who send spam, and to make all new members who join their group unable to send messages until approved.
+
+As support for large groups improves, we expect that the attempts to abuse may increase too, unless we add better moderation capabilities in advance.
+
+v6.3 will add ability of the group members to send reports to the group owners and administrators — the beta version we just released adds ability to manage these reports, so group admins won't miss reports when members start sending them.
+
+Other features that we plan to add this year to improve both usability and safety of the groups:
+- message comments — some groups may choose to allow only comments, when ability to send messages is restricted to group owners or admins.
+- ability to limit the maximum number of messages the members can send per day.
+- ability to pre-moderate messages before they can be seen by all members.
+- "knocking" — approving new members before they can join the group.
+- sub-groups — smaller conversations with the same members.
+
+## Preventing server abuse without compromising e2e encryption
+
+Some categories of content may be prohibited by servers operators. An extreme case would be child sexual abuse materials (CSAM).
+
+Many people believe that when conversation is end-to-end encrypted, the problem is unsolvable. This incorrect belief is used by unscrupulous lobbyists and politicians who attempt to mandate various types of content scanning under the guise of preventing CSAM distribution.
+
+We [wrote before](https://simplex.chat/blog/20240601-protecting-children-safety-requires-e2e-encryption.md) about how such measures not only would fail to solve the problem, but would make it worse. If our private photos become available to service providers, they will eventually become available to criminals too, and will be used to abuse and exploit the users and their children.
+
+An absolute majority of CSAM distributed online is publicly accessible. Many large tech companies failed to act on it and to remove CSAM from their services before it became an epidemic. We see it as a very important objective to eliminate the possibility to distribute CSAM from publicly accessible groups, even if it hurts network growth.
+
+When we receive a user complaint about CSAM shared in any group, we remove the files and, in some cases, the links to join the group from our servers. Our approach to moderation preserves user privacy and security of end-to-end encryption.
+
+How does it work? Let's go over the process step by step.
+
+1. A user discovered the link to join the group that distributes CSAM and sent a complaint to our support email address or via the app to [SimpleX Chat team](simplex:/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) contact.
+
+2. Once we received the link to join the group, we instruct our automated bot to join it. If the complaint is confirmed as valid, the bot sends the information about the files sent in this group to the servers that store these files.
+
+3. Once the servers receive the file identifiers from the bot, they block the files.
+
+File servers cannot look inside end-to-end encrypted files, and they don't even know file sizes — they are securely locked, and sent in chunks, across multiple servers. But if the bot that joined the group provides the address of the particular file, the server can delete this file. It doesn't allow the servers to access any other files.
+
+In this way, the moderation is possible without any content scanning, and it preserves privacy and security of end-to-end encryption.
+
+## Privacy-preserving content moderation
+
+Right now, when we act on user complaints, we delete uploaded files or the links to join the groups from our servers, and to the users it looks as if something stopped working.
+
+We are currently rolling out the change to the servers that would mark these files and group links as blocked, so that users who try to download them or to join blocked groups can see that they were blocked for violating server operator conditions of use. This will improve transparency of moderation and reliability of the network.
+
+Later this year we plan to do more than that — client-side restrictions on the clients that violated conditions of use by uploading prohibited content.
+
+How would it work? When the client discovers that the uploaded file was blocked, it may, optionally, depending on the information in the blocking record, disable further uploads from the app to the servers of the operator that blocked the file. Also, when the client that tried to receive the file sees that the file is blocked, it may also refuse to receive further files from the same group member via the same servers.
+
+In this way, the servers can restrict the future actions of the users who violate the conditions of use, while preserving privacy and security of the users and content – even of those users who violated the conditions.
+
+We discussed this plan with the users, and we really appreciate their feedback. The current plan is quite different from our initial ideas, the users had a real impact. Users asked the questions below.
+
+**Can't users modify their clients code to circumvent these restrictions?**
+
+Yes, they can, but for this to work both sender and recipient would have to modify their clients. It's technically complex, so most users won't do it, and it is also hard to coordinate between users who don't know and don't trust each other.
+
+So these measures would be effective, even though they can be in theory circumvented, as any restrictions can be.
+
+Other services that identify users reduce abuse by blocking the user account. It is even easier to circumvent than changing the client code, and yet these measures reduce abuse.
+
+**Can't users use other servers?**
+
+Yes, they can. But in the same way as web browser is not responsible for the content you can access, SimpleX app should not restrict your communications with other servers based on blocking action from just one server.
+
+That approach allows different server operators to have different content policies, depending on their jurisdiction and other factors. It also prevents the possibility of abuse by server operators.
+
+**Wouldn't these measures be abused?**
+
+With the proposed changes, server operators will only be able to prevent uploads to their own servers, which prevents any impact on other communications.
+
+In the future we plan to increase the resilience to any server malfunction or abuse by using multiple different servers with each contact.
+
+If servers were to apply any upload restrictions unreasonably, the users would simply stop using them.
+
+At the same time, server operators need to have technical means to protect their servers from users' abuse, and the proposed client-side restrictions achieve it.
+
+**What additional measures are considered?**
+
+We published other technical ideas that could be used to prevent distribution of illegal content in [this document](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2024-12-30-content-moderation.md). None of these measures compromise users' privacy or end-to-end encryption, and they can (and should) only be applied to publicly accessible content that other users complained about.
+
+We technically cannot, and we won't scan all content. We actively [campaign against any content-scanning proposals](https://simplex.chat/blog/20240704-future-of-privacy-enforcing-privacy-standards.md), because it violates our right to privacy, and it would result in huge increase of online crime.
+
+The belief that it is impossible to moderate conversations when they are e2e encrypted is incorrect. It is possible when users themselves share conversation contents with server operators, in which case the operators can identify and, if necessary, remove this content. It is also possible to moderate conversations that users made publicly accessible.
+
+## Send us comments and questions
+
+Let us know any comments and feedback to the proposed measures. This is still an evolving design, and it won't be implemented until later this year.
+
+Your comments will help to find the right balance between users' and server operators' requirements.
+
+## Privacy and security improvements we plan this year
+
+To increase privacy and security we plan to add this year:
+- quantum-resistant e2e encryption in small groups.
+- receiving proxy for files, to protect users IP addresses and other transport metadata from file senders' servers.
+
+We see privacy and security as necessary for online safety, and prevention of abuse. If you don't already use SimpleX network, try it now, and let us know what you need to make it better.
diff --git a/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html b/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html
index bdd6f2e9dd..3123d20fd8 100644
--- a/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html
+++ b/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md b/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md
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--- /dev/null
+++ b/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md
@@ -0,0 +1,178 @@
+# SimpleX Chat v6.3: new user experience and safety in public groups
+
+**Published:** Mar 8, 2025
+
+**What's new in v6.3**:
+- [preventing spam and abuse in public groups](#preventing-spam-and-abuse-in-public-groups).
+- [group improvements](#group-improvements): [mention other members](#mention-other-members-and-get-notified-when-mentioned), [improved performance](#better-group-performance).
+- [better chat navigation](#better-chat-navigation): [organize chats into lists](#organize-chats-into-lists) and [jump to found and forwarded messages](#jump-to-found-and-forwarded-messages).
+- [privacy and security improvements](#privacy-and-security-improvements): [chat retention period](#set-message-retention-period-in-chats) and [private media file names](#private-media-file-names).
+
+Also, we added Catalan interface language to Android and desktop apps, thanks to [our users and Weblate](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+The last but not the least - [server builds are now reproducible](#reproducible-server-builds).
+
+## What's new in v6.3
+
+## Preventing spam and abuse in public groups
+
+[We wrote before](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md): as the network grows, it becomes more attractive to attackers. This release adds several features that reduce the possibility of attacks and abuse.
+
+### Spam in groups that are listed in our group directory
+
+There is no built-in group discovery in SimpleX Chat apps. Instead, we offer an experimental chat bot that allows to submit and to discover public groups. Not so long ago, spammers started sending messages via bots attempting to disrupt these groups.
+
+We released several changes to the groups directory to protect from spam attacks.
+
+**Optional captcha verification**
+
+<img src="./images/20250308-captcha.png" width="288" class="float-to-right">
+
+Group owners can enable the requirement to pass captcha challenge before joining the group. Captcha is generated in the directory bot itself, without any 3rd party servers, and is sent to the joining member. The new member must reply with the text in the image to be accepted to the group. While not a perfect protection, this basic measure complicates programming automatic bots to join public groups. It also provides a foundation to implement "knocking" - a conversation with dedicated group admins prior to joining the group. We plan to release support for knocking in March.
+
+**Profanity filter for member names**
+
+While group settings support giving all joining member an "observer" role - that is, without the right to send messages - the attackers tried spaming groups by joining and leaving. We added an optional filter for member names that group owners can enable for groups listed in directory - if a member name contains profanity, they will be rejected. Further improvements will be released in March as well.
+
+The current SimpleX directory chatbot is a hybrid of [future chat relays](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md#can-large-groups-scale) (a.k.a. super-peers) we are now developing to support large groups, and of a directory service that will be embedded in the app UI later this year, allowing to search and to discover public groups. Anybody is able to run their own directory bots now, and there will be possibility to use third party directories via the app UI in the future too.
+
+Read more about [SimpleX group directory](https://simplex.chat/docs/directory.md), how to submit your groups, and which groups we now accept. Currently we accept groups related to a limited list of topics that will be expanded once we have better moderation functionality for the groups.
+
+### More power to group owners and moderators
+
+This release includes two new features to help group moderators.
+
+<img src="./images/20250308-reports.png" width="288" class="float-to-right">
+
+**Private reports**
+
+Group members can privately bring to group moderators attention specific messages and members, even if the group does not allow direct messages. The simply need to choose report in the message context menu and choose the report reason. This report will be visible to all group owners and moderators, but not to other members.
+
+Group moderators can see all member reports in a separate view, and quickly find the problematic messages, making moderation much easier in public groups. These reports are private to groups, they are not sent to server operators.
+
+Please note: in the groups listed in our directory, the directory bot acts as admin, so it will receive all reports as well.
+
+**Acting on multiple members at once**
+
+When attackers come, they often use multiple profiles. This version allows selecting multiple members at once and perform these actions on all selected members:
+- switch members role between "observer" and "member".
+- block and unblock members - this is a "shadow" block, so when you block multiple members who you believe are attackers, their messages will be blocked for all other members but not for them.
+- remove members from the group.
+
+The next version will also allow to remove members together with all messages they sent - for example, if a spam bot joined and sent a lot of spam, but nothing of value.
+
+## Group improvements
+
+### Mention other members and get notified when mentioned
+
+<img src="./images/20250308-mentions.png" width="288" class="float-to-right">
+
+This feature allows you to mention other members in the group in the usual way - type `@` character, and choose the member you want to mention from the menu. Even that there is no user accounts and persistent identities we made it work by referencing members by their random group ID that is also used for replies and all other interactions in the group.
+
+You can also now switch message notifications in the group to "mentions only" mode. You will be notified only when you are mentioned in a message, or when somebody replies to your message. Simply choose "Mute" in the context menu of the group in the list of chats to switch group notifications to "mentions only" mode. After that you can choose "Mute all" to disable all notifications, including mentions.
+
+### Better group performance
+
+**Send messages faster**
+
+We didn't reduce the required network traffic to send messages to large groups yet - your client still has to send message to each member individually. But we redesigned the process of sending a message, reducing temporary storage required to schedule the message for delivery by about 100x. This creates a significant storage saving - e.g, to send one message to a group of 1,000 members previously required ~20Mb, and now it is reduced to ~200kb. It also reduces the time and battery used to send a message.
+
+**Faster group deletion**
+
+When you leave the group, the app preserves a copy of all your communications in the group. You can choose to keep it or to delete it completely. This final group deletion was very slow prior to this release - depending on the number of groups on your device it could sometimes take several minutes.
+
+This release solved this problem – the time it takes to delete the group is reduced to seconds, and even in cases when the app is terminated half-way, it either rolls back or completes, but it cannot leave the group in a partially deleted state. It improves both user experience and privacy, as gives you better control over your data.
+
+## Better chat navigation
+
+### Organize chats into lists
+
+<img src="./images/20250308-lists.png" width="288" class="float-to-right">
+
+It is a common feature in many messengers – it helps organizing your conversations.
+
+The lists also show a blue mark when any chat in the list has new messages.
+
+There are several preset lists: contacts, groups, private notes, business chats, favourite chats and also groups with member reports - the last list is automatically shown if members of any groups where you are the moderator or the owner sent private reports, until these reports are acted on or archived.
+
+### Jump to found and forwarded messages
+
+This version allows to quickly navigate from message in the search results to the point in the conversation when it was sent.
+
+You can also navigate from the forwarded message (or from the message saved to private notes) to the original message in the chat where it was forwarded or saved from.
+
+## Privacy and security improvements
+
+### Set message retention period in chats
+
+Before this version, you could enable message retention period for all chats in your profile. While helpful in some cases, many of us have conversations that we want to keep for a long time, and some other conversations that we want to remove quicker.
+
+This version allows it - you can set different retention periods in different conversations. It can be 1 day, 1 week, 1 month or 1 year. We may allow custom retention time in the future.
+
+### Private media file names
+
+Previously there were scenarios when original media file names were preserved - e.g., when sending a video file or when forwarding any media file. The latter problem was worse, as media file name is generated automatically, and includes timestamp. So the same name could have been used to correlate files between conversations, as one of our users pointed out.
+
+This version fixes this problem - media file name is now changed when forwarding it to match the time of forwarding, so no additional metadata is revealed.
+
+Please also note:
+- the apps remove metadata from all static images,
+- iOS app removes metadata from videos, but android and desktop apps do not do it yet,
+- animated images are sent as is,
+- other file types are sent as is, and their names are left unchanged - we believe that for ordinary files their name is part of their content.
+
+We plan further improvements to reduce metadata in files in the near future – please let us know what you believe is the most important to reduce first.
+
+## Reproducible server builds
+
+Starting from v6.3 server releases are reproducible!
+
+**Why it is important**
+
+With reproducible builds anybody can build servers from our code following the same process, and the build would produce identical binaries.
+
+This also allows us to sign releases, as we reproduce GitHub builds ourselves and by signing them we attest that our builds resulted in identical binaries.
+
+**How to reproduce builds**
+
+You can reproduce our builds on Linux with x86 CPU in docker container - please follow the instructions [here](https://simplex.chat/docs/server.md#reproduce-builds).
+
+We are looking for support from open-source contributors or security researchers who would also reproduce and sign our releases.
+
+**How to verify release signature**
+
+Please see the instructions [here](https://simplex.chat/docs/server.md#verifying-server-binaries).
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/#please-support-us-with-your-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html b/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html
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--- a/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.md b/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.md
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@@ -0,0 +1,182 @@
+# SimpleX network: new experience of connecting with people — available in SimpleX Chat v6.4-beta.4
+
+**Published:** Jul 3, 2025
+
+The mission of communication network is connecting people [1]. The process of connecting in SimpleX network is really secure — it is protected from server MITM attacks. But before this beta version connecting to contacts had a really bad user experience.
+
+## What was the problem?
+
+How did it work before:
+
+1. Your contact created a large link (1-time invitation or contact address [2]) and shared with you via another messenger, email, social profile or website. Sharing the link "out-of-band" (i.e., not via the server) is necessary for security. But it was not working well in some cases:
+  - the link was incorrectly changed by some applications, e.g. Telegram, because of link complexity, preventing people from connecting.
+  - some people were worried that the link "looks like malware".
+  - the QR code for the link was large, and sometimes difficult to scan.
+  - the link did not fit the size limit in social media profiles.
+2. Once you received the link, you used it in the app. But when using the link you could not see who you were connecting to. The only choice you had is to share your current profile or to use incognito profile. And as people didn't know which profile will be shared with them, many were choosing to share incognito profile, making recognizing contacts more complex — you don't know who is who unless you attach aliases to incognito contacts.
+3. Once you tap Connect, all you see is the line in the list of chats that said "Connecting via link". The process of connection required your contact to be online, and in some cases to approve the request, so you may had contact in "connecting" state for a really long time.
+
+So it is not surprising that a large number of people failed connecting to friends — either they refused to engage because of large and scary looking links, or their application made the link unusable, or they abandoned the process at step 3, deciding that the app is not working correctly.
+
+## Why can't we just use usernames?
+
+Many people asked — why don't you just use usernames or a link shortener for some really short links, as other networks and apps do.
+
+The problem is that usernames or very short links make e2e encryption security of your chats dependent on the servers. Unless the link you share contains enough randomness in it and is cryptographically linked to the encryption keys, the servers can substitute the e2e encryption keys and read all your communication without you knowing it. We see this risk as unacceptable.
+
+Mitigation against this "man-in-the-middle" attack by the server [3] is offered by Signal and other apps via security code verification [4], when you compare the numeric code in your app with your contact's app, but:
+- most people do not verify security codes, and even if they do, they do not re-verify them every time security code changes, so their security is dependent on the server not being compromised, which is not a great security,
+- the servers can still compromise the initial messages, where profile names are exchanged, before you had the chance to verify the security codes.
+
+When we design communication protocols for SimpleX network we always aim to protect you from the attack via your network operators — this is what sets SimpleX network design apart from many other communication networks and platforms.
+
+Even though you choose the servers that you trust, and they are bound by privacy policy, and we follow the best security practices to protect servers from any 3rd party attacks, there is still a possibility that servers may be compromised by some attackers, and unless your communications are not protected from the servers, they are not protected from whoever can compromise the servers [5].
+
+## What is the new way to make connections?
+
+Before diving into the details of technology, let's walk though the new process of connecting to people that is introduced in [v6.4-beta.4](https://github.com/simplex-chat/simplex-chat/releases/tag/v6.4.0-beta.4).
+
+<img src="./images/20250703-card.jpg" width="288" class="float-to-right">
+
+1. As before, to connect you or your contact need to create a 1-time invitation or a contact address link. All the past problems of the long links are now solved:
+  - this link is correctly processed by all applications, as it has a simple structure,
+  - it is short and simple, e.g. the SimpleX Chat team address for support is: https://smp6.simplex.im/a#lrdvu2d8A1GumSmoKb2krQmtKhWXq-tyGpHuM7aMwsw
+  - the QR code is now much smaller, fits a standard business card, and is easy to scan from all devices,
+  - it fits in most social media profiles.
+
+While the link is short, it still contains 256 bits of key material with additional 192 bits of server-generated link ID for one-time invitation links, so the connection is as secure as before, and in case of one-time invitations it became more secure (see below).
+
+<img src="./images/20250703-connect2.png" width="288" class="float-to-right"> <img src="./images/20250703-connect1.png" width="288" class="float-to-right">
+
+2. As before, you have to use this link in the app, either by pasting the link or scanning QR code. But now you instantly see the name of your contact or group you are connecting to, and from v6.4.1 that will be released this July you will also see a profile image (currently disabled for backward compatibility).
+
+3. Once you tap "Open new chat", the app will instantly open a conversation with your contact. As you now can see which profile is shared with you via the link, you can choose which of your profiles to use to connect. If your contact shared an incognito pseudonym, then you may also choose to connect incognito. But if your contact shared a real name, you may want to share your real name as well, making it easier for your contact to recognize you — the law of reciprocity in action! **In any case, your and your contact's profile names are inaccessible to messaging servers — they are e2e encrypted**.
+
+If you are connecting via a contact address you can also add a message to your request, making it more likely to be accepted when connecting to somebody you don't know well. And from v6.4.1 contact addresses can include a welcome message that you would see before connecting, right in the conversation. This way, you effectively become connected to your contact and start a secure conversation even before you tap "Connect" button.
+
+If you are connecting via a one-time invitation link, all you need to do is to tap "Connect", and then you can send messages straight after that, without waiting for your contact to be online — they will be securely received later.
+
+This new experience of connecting is very similar to commonly used messengers, but it protects your security. We hope that it will be much easier for the new users to connect to their friends.
+
+## What about security?
+
+We took a great care to design the protocol extension for the new experience of connecting in a way that not only preserves security at the same level as before, but also increases security of connecting via one-time invitation links.
+
+First, because all the keys are now included in encrypted link data on the server, and not in the link itself as before, we can include the keys for post-quantum (PQ) key exchange and make the first message sent via one-time link (your profile) encrypted with PQ e2e encryption. Previously, PQ encryption started only after the response from your contact.
+
+Second, whoever can observe the link is not able to determine which public keys are used in key exchange and what messaging queue address is used, and this data is removed from the server once the connection is established. Previously, the invitation link contained public keys and the actual queue address that could have been used for a long time, unless you rotated it.
+
+Third, if somebody retrieves the associated data of one-time invitation link they observed in transit, this link would become inaccessible for the intended recipient, so the recipient would know that the connection was potentially compromised, and would alert the contact that sent the link.
+
+## How does it work?
+
+In short, a new short link references a container with the encrypted data on the server that contains:
+- the original full link that now include quantum-resistant keys that previously were not included because of their size,
+- contact's or group's profile and conversation preferences, from v6.4.1 it will include profile images,
+- also, it will include an optional contact's or group's welcome message from v6.4.1.
+
+Making user profile and welcome message included in the encrypted link data allows to start conversation as soon as you scan the link, as described in the previous section.
+
+### Design objectives and cryptographic primitives that achieve them
+
+This section is not a formal specification of the protocol, but an informal technical explanation of objectives we had for this design and how they were achieved. The technical details are available in [this RFC document](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2025-03-16-smp-queues.md).
+
+1. **Encrypted link data cannot be accessed by the server**.
+
+It means that while the client apps should use the link to derive both the link ID for the server and decryption key for the associated link data, the server should not be able to derive the link and decryption key from the link ID that it knows, and can't access the link data.
+
+This objective is achieved by using `secret_box` encryption of link data with the symmetric key derived from link URI, which is different from link ID known to the server. As it is a symmetric encryption, it is secure against quantum computers.
+
+2. **Allow changing encrypted link data without changing the link itself**.
+
+This is necessary to allow changes in user profile, chat preferences and welcome messages.
+
+This is possible via a specific server request that allows to change user-defined part of the link data to the link owner. Because the link is derived from fixed part of the link data, the link itself remains the same.
+
+3. **Prevent MITM attack on the link data by the server, even if the server obtained the link**.
+
+It means that the server should not be able to replace the associated link data even if it somehow obtained the link and can decrypt the data.
+
+This objective is achieved by deriving encryption key from the hash of the fixed part of the link data — if server changes the link data, it would be rejected by the client, as its hash won't match the link. Server also cannot replace the user-defined part of the link data, because it is signed and will be verified with the key included in the fixed part of link data.
+
+Clients use `HKDF` for key derivation, `SHA3-256` to compute hash of the fixed part of link data, and `ED25519` signature to sign user-defined link data.
+
+4. **Prevent undetectably accessing encrypted link data of one-time links**.
+
+This is explained in the previous section — if link observers retrieve the link data, the link will become inaccessible for the intended recipient.
+
+This objective is achieved because the link data of 1-time invitation link data can only be accessed with the server request that locks queue on the first access. Any subsequent access to the queue must uses the same authorization key (`ED25519`).
+
+5. **The link owner cannot include address of another queue in the link**.
+
+It means that the link cannot redirect the connecting party to another server or to another queue on the same server — the apps would reject the links that attempt to do it. While allowing redirects may be seen as higher security from the server, it would open the possibility of resource exhaustion attacks, as the server would not know if the links were actually used to connect or not, and when the link data can be removed. So we decided that preventing redirects is a better tradeoff. This cryptographically enforced association between link and queue allows to remove link data from the server once the connection is established, or once some time passes (e.g., 3 weeks for unused one-time invitation links).
+
+This objective is achieved by including queue ID and link data into the same server response.
+
+6. **Prevent link owner from being able to change the queue address and encryption keys in the link**.
+
+This quality prevents the MITM attack on e2e encryption via break-in attack on the client of the link owner.
+
+The server does not provide any API to change the fixed part of the link data. Also, changing fixed data would require changing the link, as otherwise the hash of the data won't match the link.
+
+7. **It should be impossible to check the existence of a messaging queue for one-time invitation links**.
+
+It means that any 3rd party that observed 1-time invitation link (e.g., by reading the message in the messenger or email where it was sent) must not be able to undetectably confirm whether this messaging queue still exists, by attempting to create another queue with the same link ID and the same link data.
+
+This objective is achieved by servers requiring that sender ID is derived (using `SHA3-384`) from request correlation ID, so an arbitrary sender ID cannot be used, and by generating link ID on the server — for 1-time invitation link, the link ID is included in the link in addition to link key, and is not derived from the link data.
+
+See the detailed [threat model](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2025-03-16-smp-queues.md#threat-model) for protocol extension supporting the new user experience of making connections.
+
+## Let us know what you think!
+
+We worked really hard to deliver this big change — the simplicity of user experience required to hide a lot of complexity under the hood. We really hope that it will help you to bring more of your friends to SimpleX network and to benefit from using secure communications.
+
+The stable versions v6.4 and v6.4.1 will be released this July, but you can already use the beta version available via [Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app) (Android), [Test Flight](https://testflight.apple.com/join/DWuT2LQu) (iOS) and [GitHub](https://github.com/simplex-chat/simplex-chat/releases/tag/v6.4.0-beta.4) (Android and desktop).
+
+Big thank you to everybody who uses SimpleX network, even though the experience of connecting to people was complex before this release.
+
+With your help, SimpleX network should be able to get over the million active users now!
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/#please-support-us-with-your-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
+
+[1]: An interesting case study is the rise and fall of Nokia as the dominant supplier of mobile phones. The slogan "Connecting people" was created in 1992 by Ove Strandberg, an intern at Nokia, and as it was adopted as the core mission of the company, we saw it rise as the world's main mobile phone supplier. The fall of Nokia is usually attributed on iPhone success. But it may also be attributed to internal cultural changes, with Nokia's communications chief leaving in early 2000s, and Nokia failure to understand how the definition of "Connecting people" should evolve with time.
+
+[2]: One-time invitation can only be used once by the person you gave it too. Once your contact scans the one-time link, nobody else can connect to you via this link. Contact address can be used by multiple people, and even if you later delete the address, everybody who connected to you will remain connected. You can read more about the differences between one-time invitation links and contact addresses [here](https://simplex.chat/docs/guide/making-connections.md#comparison-of-1-time-invitation-links-and-simplex-contact-addresses).
+
+[3]: Read more about how man-in-the-middle attack works in our [post about e2e encryption properties](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md#5-man-in-the-middle-attack-mitigated-by-two-factor-key-exchange). It also has the comparison of e2e encryption security in different messengers.
+
+[4]: SimpleX apps also allow security code verification, but it protects against different attack — the link substitution by the channel you use to pass it, not from the attacks by the servers — SimpleX servers cannot compromise e2e encryption.
+
+[5]: That is also why "securely scanning users' communications", also known as "Chat Control" is impossible — what communication operator can access, cyber-criminals will also access, and instead of reducing crime it would expose users to more crime.
diff --git a/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html b/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html
index 4630d24d4e..9829b30b55 100644
--- a/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html
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@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.md b/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.md
new file mode 100644
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--- /dev/null
+++ b/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.md
@@ -0,0 +1,141 @@
+# SimpleX Chat v6.4.1: welcome your contacts, review members to protect groups, and more.
+
+**Published:** Jul 29, 2025
+
+**What's new in v6.4.1**:
+
+- [welcome your contacts](#welcome-your-contacts-the-new-experience-of-making-connections): set your profile bio and welcome message.
+- [protect your communities](#protect-your-groups) from spam and abuse:
+  - review new members ("knocking"),
+  - moderator role to delegate message moderation to trusted members,
+  - receive direct feedback from your group members.
+- [other improvements](#other-improvements): set default time to delete messages for new contacts.
+- [improved app integrity](#improved-app-integrity).
+
+Also, we added 3 new interface languages to Android and desktop apps: Indonesian, Romanian and Vietnamese.
+
+Huge thanks to our users who [contributed translations](https://github.com/simplex-chat/simplex-chat#help-translating-simplex-chat).
+
+## What's new in v6.4.1
+
+### Welcome your contacts: the new experience of making connections
+
+<img src="./images/20250729-connect2.png" width="288" class="float-to-right"> <img src="./images/20250729-connect1.png" width="288" class="float-to-right">
+
+The new simple way to connect to your friends is fully available in this version.
+
+We received many compliments from our users who started using it in beta versions and in v6.4 about how it simplifies connecting with friends. We agree - this is the biggest UX revolution since the app was released.
+
+Instead of connecting blindly, and waiting until your contact is online, as it was before, you can now see profile and welcome message of the person you connect to, before you connect.
+
+When you tap Open new chat you can decide which profile to use to connect or if you want to connect incognito, and in some cases you can include a message with your connection request.
+
+This way, the conversation with your friends starts even before they connect to you!
+
+For previously created SimpleX addresses and group links you have an option to upgrade. The links will become short, and will include profile information into link data. Old long links will continue to work, so you won't lose any contacts or members during the upgrade.
+
+These links are now short enough to be shared in your social media profiles - they are less than 80 characters.
+
+And as before, it is as secure - servers cannot see you profiles, unless they have the link, and cannot modify them even if they somehow get the link. You can read more about security property and other technical details in our [post about SimpleX protocols extension](https://simplex.chat/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.md) supporting this new user experience.
+
+Thank you for bringing your friends to SimpleX network!
+
+### Protect your groups
+
+<img src="./images/20250729-join2.png" width="288" class="float-to-right"> <img src="./images/20250729-join1.png" width="288" class="float-to-right">
+
+**Review new members**
+
+Since v6.4 there are some major improvements in your ability to protect your group from spam and abuse.
+
+You can enable an option to review all new group members. It is also commonly called "knocking". It allows you to:
+- ask prospective members any questions,
+- explain the group rules,
+- make sure their profile is appropriate for the group,
+- decide whether to allow them joining the group, and whether they should be able to send messages in the group.
+
+Some small groups may enable member review permanently, while larger public groups may enable it temporarily during spam/troll attacks.
+
+**New role for group moderators**
+
+In addition to that, there is a new group role - moderator.
+
+This role allows:
+- to approve members in review,
+- moderate messages,
+- block members for all.
+
+Unlike admins, moderators can't add new members or permanently remove members from the group. This allows you to delegate group moderation to your community members without risking that they may disrupt the group.
+
+**Receive direct feedback from group members**
+
+Your group members now can send messages to group admins. Each conversation with a group member is a mini-group where all group owners, admins and moderators can talk to a member. Reports that members can send [since v6.3](https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md) are also added to chat with member, allowing you to discuss the report.
+
+### Other improvements
+
+**Enable disappearing messages for new contacts**
+
+Now you can enable disappearing messages for all new contacts automatically. Tap your profile image in the corner, then tap Chat preferences and set time for messages to disappear.
+
+**Improved message delivery**
+
+We improved networking layer by increasing request timeouts for all background requests. It substantially reduces traffic on slow networks.
+
+### Improved app integrity
+
+**Supply chain security**
+
+The app security depends on security of its components and its build process, and many of these components are created by third parties. In this version we improved the build process to control the upgrades of these components:
+- all 3rd party GitHub actions used during the build are now moved to [the forks we control](https://github.com/simplex-chat?q=action&type=fork&sort=name) - it prevents supply chain attacks via build actions.
+- we now build VLC library for all platforms from the source code ourselves, in [this repository](https://github.com/simplex-chat/vlc).
+- SQLCipher and [Haskell dependencies](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/dependencies/HASKELL.md) versions were already "locked" prior to this version.
+
+**Automatic virus scanning**
+
+We now run automatic daily virus scanning of all apps released via GitHub using [VirusTotal.com](https://www.virustotal.com/).
+
+You can see the scan results [here](https://github.com/simplex-chat/simplex-virutstotal-scan).
+
+**Reproducible builds**
+
+In addition to [server builds](https://github.com/simplex-chat/simplexmq/releases/tag/v6.4.1) that were reproducible since v6.3, the builds of Linux CLI and desktop apps are now reproducible too. You can build Linux apps from source using [this script](https://github.com/simplex-chat/simplex-chat/blob/master/scripts/simplex-chat-reproduce-builds.sh).
+
+*Please note*: Linux package upgrades may change the build.
+
+Stable builds of Linux apps are now independently reproduced and [signed by our and Flux teams](https://github.com/simplex-chat/simplex-chat/releases/tag/v6.4.1) - it verifies the integrity of GitHub builds.
+
+Huge thanks to [Flux](https://runonflux.com/) for doing that and for providing their servers via the app.
+
+## SimpleX network
+
+Some links to answer the most common questions:
+
+[How can SimpleX deliver messages without user identifiers](https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.md#the-first-messaging-platform-without-user-identifiers).
+
+[What are the risks to have identifiers assigned to the users](https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.md#why-having-users-identifiers-is-bad-for-the-users).
+
+[Technical details and limitations](https://github.com/simplex-chat/simplex-chat#privacy-and-security-technical-details-and-limitations).
+
+[Frequently asked questions](https://simplex.chat/faq/index.html).
+
+Please also see our [website](https://simplex.chat).
+
+## Please support us with your donations
+
+Huge *thank you* to everybody who donated to SimpleX Chat!
+
+Prioritizing users privacy and security, and also raising the investment, would have been impossible without your support and donations.
+
+Also, funding the work to transition the protocols to non-profit governance model would not have been possible without the donations we received from the users.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+Your donations help us raise more funds — any amount, even the price of the cup of coffee, makes a big difference for us.
+
+See [this section](https://github.com/simplex-chat/simplex-chat/#please-support-us-with-your-donations) for the ways to donate.
+
+Thank you,
+
+Evgeny
+
+SimpleX Chat founder
diff --git a/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html b/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html
index ce4aafc1e5..c71ffc37c5 100644
--- a/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html
+++ b/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md b/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md
new file mode 100644
index 0000000000..da8a31ff1b
--- /dev/null
+++ b/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md
@@ -0,0 +1,59 @@
+# SimpleX Channels, SimpleX Network Consortium and Community Crowdfunding — to Preserve Freedom of Speech
+
+**Published:** Apr 30, 2026
+
+Freedom of speech needs infrastructure that protects it by design — not only the protocols and servers, but the governance and funding to support them.
+
+## SimpleX Channels — more public, more freedom, more private
+
+<img src="./images/20260430-channel.png" width="264" class="float-to-right">
+
+v6.5 release[^release] brings SimpleX Channels: a new model for online publishing built for participation privacy.
+
+Channel content is visible to chat relay operators. And each channel uses multiple relays, so no single relay can block the channel[^preset].
+
+But the real identities of channel owners and subscribers are unknown to relay operators, to each other, and to the network. This is important for freedom of speech and for our ability to say the truth[^wilde].
+
+This is the opposite of the usual approach: instead of trying (and failing [^public]) to hide publicly available content from operators while exposing participants, we designed the protocols to protect people. Anybody can join a public channel via its link and see what is sent, but not who sent it, and not who else is reading. This is win-win for both users and chat relays operators. Users' privacy is protected, operators can decide what content to deliver in public spaces, and anybody can run chat relays.
+
+This is only possible because SimpleX network was built without user profile identifiers of any kind. You can't add participation privacy to a network that identifies its users — as you can't add privacy to a messenger built on phone numbers.
+
+v6.5 is the first beta version of channels:
+- channel owners hold their own channel keys,
+- each channel uses multiple relays for reliability,
+- publishers can run their own chat relays,
+- channels can be added to our [SimpleX Directory](https://simplex.chat/directory/).
+
+This release is a beginning of a very important new layer of SimpleX Network. Read more about channels in [whitepaper](https://github.com/simplex-chat/simplex-chat/blob/master/docs/protocol/channels-overview.md): their purpose, architecture, security model and planned future work.
+
+## SimpleX Network Consortium — to preserve network independence
+
+No single company should control protocols and network that people depend on to speak freely. If a network is run by a single company, the network has a risk that business and users interests diverge — if it happens, users lose.
+
+To protect network neutrality and make sure its protocols and intellectual property are available to the users, we're launching [SimpleX Network Consortium](https://simplexnetwork.org) within a few months — the agreement between the new SimpleX Network Foundation and SimpleX Chat company that will govern protocols and licensing — perpetual, irrevocable, surviving if any party is sold or shut down. Other organizations will join.
+
+We are currently forming the board for SimpleX Network Foundation — initially, [Heather Meeker](https://heathermeeker.com/about-me/), who drafted the Consortium agreement, and several other people will join. We will announce the board soon.
+
+As the power over the network protocols moves away from the company, it cannot move back[^ulysses]. It is a structural guarantee — the same principle we applied to privacy.
+
+## Community Crowdfunding
+
+We've seen open-source privacy-focussed projects die without funding, or worse — being captured by their sponsors. We've seen "don't be evil" companies get lured off course by growth and board pressure. Neither pure ideology nor pure commerce survives the long run alone.
+
+So we're building both: a governance structure and a real business. The governance protects the network neutrality. The commercial model funds the network and makes our and other businesses on the network profitable, ensuring their independence. Neither works without the other.
+
+We recently published [a preliminary design of commercial model](https://simplex.chat/credits/) — private Community Credits that fund servers, development, and governance without surveillance or speculation.
+
+Aug 20, 2026: We now launched [equity crowdfunding on Wefunder](https://wefunder.com/simplex.chat?utm_source=blog). Please read [the next blog post](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md) about it.
+
+Join the channel for updates [simplex.chat/crowdfunding-news](https://simplex.chat/crowdfunding-news/).
+
+[^release]: v6.5 release also improved how new users make the first connection, increased security of sending web links, and has many other improvements — see *What's new* in the app or full release notes.
+
+[^preset]: Currently there is only one preset operator of chat relays in the app. It will change in the next release.
+
+[^wilde]: Oscar Wilde wrote: *"Man is least himself when he talks in his own person. Give him a mask, and he will tell you the truth"*. Privacy is essential for our ability to say the truth, and without truth we cannot survive as society.
+
+[^public]: From whitepaper: any channel joinable via a public link, whether encrypted or not, must be considered completely public — the cost of joining through automated means has collapsed with large language models. End-to-end encrypting such content provides no privacy; it only undermines users' security by creating false expectations and increases infrastructure operators' risks by making them unable to see what they deliver.
+
+[^ulysses]: Ulysses pact — adding constraints to reduce future options. Sé Reed used this analogy for the WordPress Foundation: tying the project to the mast before the siren songs of commercial capture (https://www.wpwatercooler.com/wpwatercooler/ep484-whose-wordpress-is-it-anyway/).
diff --git a/blog/20260722-simplex-public-names.html b/blog/20260722-simplex-public-names.html
index 1b5c86cd4d..75dcba9516 100644
--- a/blog/20260722-simplex-public-names.html
+++ b/blog/20260722-simplex-public-names.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20260722-simplex-public-names.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20260722-simplex-public-names.md b/blog/20260722-simplex-public-names.md
new file mode 100644
index 0000000000..7f049e6e65
--- /dev/null
+++ b/blog/20260722-simplex-public-names.md
@@ -0,0 +1,56 @@
+# SimpleX Public Names — a Name Nobody Can Take From You
+
+**Published:** Jul 22, 2026
+
+You can now give your channel or business a test SimpleX name that people can remember. Test names are available from v7-beta[^testing].
+
+## Public names for channels and businesses — without user IDs
+
+<img src="./images/20260722-phone-name.webp" width="19%" class="float-to-right dark:hidden">
+<img src="./images/20260722-phone-name-light.webp" width="19%" class="float-to-right hidden dark:block">
+
+Before names, the only way to bring people to your channel or business on SimpleX Network was a link — but you cannot use a link in a podcast or a poster: nobody would remember it.
+
+Every place where you could get a name so far belongs to someone else: Telegram can revoke your username, a registrar can suspend your domain.
+
+So we designed SimpleX names for no one to own the registry — on the Ethereum blockchain. If you register `example.simplex`, people type `#example` to join your channel, or `@example.simplex` to message you. If a server operator deletes your link, you can point the name to a new one. Only you control the name with the key in your wallet[^ens].
+
+And we did not add user identifiers to do it. Names are only for those who want to be found — channels, businesses, communities — and servers still cannot see who joined your channel or wrote to you.
+
+We plan to launch `.simplex` names later this year, and to provide the first names to [crowdfunding investors](#community-crowdfunding) as perks.
+
+## How to register a name
+
+<img src="./images/20260722-register-name.png" width="38%" class="float-to-right">
+
+To register a test name you need an Ethereum wallet, such as MetaMask, and your SimpleX address or channel link from the app.
+
+Setting up a name takes two steps. On the SimpleX Name Service [test webpage](https://testing-names.simplex.chat), search for the name you want — currently 6 characters or more — paste your address or channel link into the page, and complete the registration.
+
+In the app, you need to claim the name for your channel or contact address — it prevents connecting to your channel or address via any other name. Open your SimpleX address or channel page, tap **Get SimpleX name**, enter the name, and tap Save.
+
+See [this guide](https://simplex.chat/docs/guide/register-simplex-name.md) for more details.
+
+## How to connect via names
+
+<img src="./images/20260722-connect-name.png" width="288" class="float-to-right">
+
+Type the name into the search bar — `#example.testing` to join the channel, `@example.testing` to send direct messages. You can also send names in messages — they work as links.
+
+Connecting via a name is private. Unlike most applications accessing the chain through a centralized RPC service, SimpleX Chat app resolves names via two independent servers of SimpleX Network, so that no server can see both the name and the user's IP address.
+
+Read more about names in the [whitepaper](https://github.com/simplex-chat/simplex-chat/blob/master/docs/protocol/names-overview.md): their purpose, architecture, security model and planned future work.
+
+## Community Crowdfunding
+
+To ensure the long term success of SimpleX Network we established [SimpleX Network Consortium](https://simplexnetwork.org/consortium.html) — an agreement between a non-profit foundation created for protocol licensing and governance and SimpleX Chat, Inc.
+
+The commercial model for the network that we are building aims to make both our and other businesses on the network profitable. We recently [presented the technology design](https://www.youtube.com/watch?v=UhW8AuoRgxg) for this commercial model at Web3 Summit.
+
+Aug 20, 2026: We now launched [equity crowdfunding on Wefunder](https://wefunder.com/simplex.chat?utm_source=blog). Please read [the next blog post](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md) about it.
+
+Join the channel for updates [simplex.chat/crowdfunding-news](https://simplex.chat/crowdfunding-news/).
+
+[^testing]: Test names are free to register; you only need to pay the blockchain fee. The `.testing` namespace is temporary — test names will stop working in the app one month after `.simplex` name sales launch.
+
+[^ens]: SimpleX Name Service (SNS) is a fork of Ethereum Name Service (ENS), but without its centralized dependencies. ENS depends on an off-chain indexer and a hosted metadata service. SNS is fully decentralized — names are indexed and hosted on the blockchain. See [Differences from ENS](https://github.com/simplex-chat/simplex-chat/blob/master/docs/protocol/names-overview.md#differences-from-ens).
diff --git a/blog/20260819-simplex-chat-crowdfunding.html b/blog/20260819-simplex-chat-crowdfunding.html
index 5b2af88175..6a21a345d8 100644
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+++ b/blog/20260819-simplex-chat-crowdfunding.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20260819-simplex-chat-crowdfunding.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20260819-simplex-chat-crowdfunding.md b/blog/20260819-simplex-chat-crowdfunding.md
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@@ -0,0 +1,62 @@
+# Equity Crowdfunding Launched — You Can Get a Stake in SimpleX Chat
+
+**Published:** Aug 20, 2026
+
+SimpleX is the first and the only messaging network without user identifiers of any kind. Our equity crowdfunding round is now launched on Wefunder, so network users, and anybody else, can get a stake in SimpleX Chat.
+
+## A network that cannot know who you are, or who you talk to
+
+<img src="./images/20260819-growth-chart.png" width="40%" class="float-to-right">
+
+People found SimpleX without any paid marketing — the community spread it via hundreds of posts, videos, podcasts and talks.[^links] The app was downloaded more than 3 million times. About 480,000 people use it every month. Users, including Vitalik Buterin, donated $650,000. There are more than 1,000 community-run servers on the network. Trail of Bits audited it in 2022, 2024, and 2026 (to be published).
+
+SimpleX Network assigns no identifiers to users — no phone numbers, usernames, or even random numbers. Instead, random identifiers are assigned to conversations, and only users know who they talk to. This cannot be added to a network that already has identifiers; it has to be built this way from the start, as SimpleX Network was.
+
+All other messengers, even private ones, may hide your name but still tag you with some number or key. That identifier links your conversations together, and the pattern of who you talk to can reveal who you are, even without names, as a 2009 study showed.[^deanon]
+
+## Why it matters now
+
+There are three trends that increase the demand for identity-free messaging that no other existing network can provide.
+
+**Surveillance of private life**. Big centralized platforms are increasingly scanning private messages to train AI models. More people would move to use private messaging that can't know who they talk to.
+
+**Accelerating deplatforming**. Creators are removed from centralized platforms without due process, and an audience built over years can disappear with one policy change. Telegram alone blocked 44 million groups and channels in 2025.
+
+**AI agents**. Agents are beginning to act for people, handling logins and money. Whoever controls an agent's identity can shut it down, or turn it against the person it works for. The same AI can fake a real person too.[^arup] User-controlled IDs are a basic security for the agentic Internet.
+
+On SimpleX Network the users, not the network, control their identities, and it solves all three problems — users cannot be surveilled or deplatformed by the network, or attacked by somebody who they have no connection with.[^address] The only keys to user connections are held by the users themselves.
+
+## SimpleX is not just a messenger — it's a network to build on
+
+<img src="./images/20260819-developers.png" width="40%" class="float-to-right">
+
+SimpleX is used for private messaging, but it also brings together communities, creators, businesses, developers and server operators. Each group makes the network more valuable to the others.
+
+Most people want more from a messenger than to connect and send texts — they want to share experiences, and every messenger builds its own. That user experience is what prevents messaging apps from converging to one protocol, the way other networks did.[^network]
+
+The web solved this by letting anyone build any experience on one open platform. SimpleX Network is evolving into that kind of platform, and developers already build on it: moderation and AI bots, bridges, and more, with over 19,000 stars on GitHub. Soon it will be possible to build custom interfaces inside a chat. Every service developers build on SimpleX makes the network more useful and brings new people in, without locking them into a single provider.
+
+## Now you can get a stake
+
+<a href="https://wefunder.com/simplex.chat?utm_source=blog"><img src="./images/20260819-wefunder.jpg" width="40%" class="float-to-right"></a>
+
+SimpleX Chat is the company that builds SimpleX Network, and now you can invest from $100 and get a stake in the company.
+
+If you invest $500 or more, you receive [a public SimpleX name](https://simplex.chat/blog/20260722-simplex-public-names.md) on SimpleX Network:
+- for 7 years, if you invest by September 22,
+- for 5 years for early bird investors,
+- for 3 years after that.
+
+You may benefit from the company's growth, and you would help build a network that people own — where the communities and audiences you build stay yours, and no company can take them away.
+
+Read about how we plan to make SimpleX Chat and the network profitable, and about all the investment terms, on Wefunder: [https://wefunder.com/simplex.chat](https://wefunder.com/simplex.chat?utm_source=blog)
+
+[^links]: https://simplex.chat/links/
+
+[^deanon]: Narayanan & Shmatikov, *De-anonymizing Social Networks* (2009): a third of the users with accounts on both Twitter and Flickr were re-identified in the anonymised Twitter graph, from its structure alone, at a 12% error rate. Sources: [arXiv 0903.3276](https://arxiv.org/pdf/0903.3276), [Narayanan, 33 Bits of Entropy](https://33bits.wordpress.com/2009/03/19/de-anonymizing-social-networks/), [Princeton listing](https://collaborate.princeton.edu/en/publications/de-anonymizing-social-networks/).
+
+[^arup]: In 2024, a video call of deepfakes cost Arup $25 million.
+
+[^address]: SimpleX Network supports public addresses, for users who want to accept connections from anybody, e.g. for a business, but these addresses are opt-in. When users use only one-time connection links, nobody can connect to them.
+
+[^network]: All networks converged to a single protocol, starting from railroads, and ending to a World Wide Web. A single unified network can create more value that several disconnected networks.
diff --git a/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html b/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html
index 5e586f489e..d723dfa2f9 100644
--- a/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html
+++ b/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20260908-nick-rogers-why-i-backed-simplex-chat.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20260908-nick-rogers-why-i-backed-simplex-chat.md b/blog/20260908-nick-rogers-why-i-backed-simplex-chat.md
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@@ -0,0 +1,73 @@
+# Why I Backed SimpleX Chat in 2022, and Why I Doubled Down
+
+**Published:** Sep 08, 2026
+
+*By [Nick Rogers](https://x.com/nickwd), Early Investor and Advisor, SimpleX Chat | Founder, Fieldwork | former CPO & CTO, Stream (Wagestream)*
+
+---
+
+When I first met Evgeny at Wagestream (now Stream) back in 2020, he was one of the most unique people I had ever encountered in technology. 
+
+He was fiercely, relentlessly honest. In a tech industry where corporate diplomacy usually trumps candour, that honesty struck me as genuine bravery. Evgeny was never afraid to speak truth to authority, and he held an uncompromisingly high bar for technical truth.
+
+In late 2021, when he decided to step down as VP of Engineering to build a brand new messaging protocol from scratch, I took over as VP of Engineering. 
+
+I knew how massive the shoes were that I had to fill. But more than that, I knew that whatever Evgeny set out to build next, he would pursue with absolute conviction.
+
+Most people in software already know Evgeny without realizing it. He is the creator of **Ajv** (Another JSON Schema Validator), one of the most widely used open source libraries in the JavaScript ecosystem, downloaded over a billion times each month by virtually every major technology company on earth. When someone has already built foundational infrastructure that the entire web secretly depends on, you take notice when they turn their attention to a new problem.
+
+### The 2022 Bet: Backing a Protocol Before It Had Users
+
+When Evgeny first pitched me on **SimpleX Chat**, his ambition was enormous: build an alternative to WhatsApp and Telegram that fundamentally eliminated user identifiers.
+
+No phone numbers. No email addresses. No usernames. Not even a persistent public key or random user ID.
+
+My first thought was that competing with WhatsApp was wildly ambitious. But as an engineering leader, I also knew there was a massive, structural gap in the market. 
+
+People assume end-to-end encryption solves privacy. It does not. WhatsApp, Telegram, Signal, and Matrix still rely on centralized account registries or user identifiers. Even when the message payload is encrypted, the platforms still collect, analyze, and classify the metadata: who you are, who you talk to, at what time, and from where. Between on-device classification, advertising networks, and platform-level censorship, modern messaging is fundamentally broken at the protocol layer.
+
+When I wrote one of the first angel checks into SimpleX's SEIS round in early 2022 (at a $5M valuation), there were no mobile app store rankings. There was barely a user base. It was essentially a Haskell terminal prototype on GitHub and Evgeny's mathematical conviction that you could route messages over isolated, unidirectional queues without ever tracking who was talking to whom.
+
+I invested because I believed in the architectural insight, and because I knew Evgeny was stubborn enough to work on this until it succeeded.
+
+### Four Years Later: The Inflection Point
+
+Over the last four years, as an investor and advisor, I have watched that initial command-line prototype grow into a global network:
+
+* **Almost 500,000 Monthly Active Users** (up from zero when I invested).
+* **3 Million+ App Downloads** and **over 20 Million messages per day**.
+* **Zero paid marketing spend.**
+
+SimpleX has reached this size because it started with the people who need uncompromising privacy the most: journalists, whistleblowers, developers, cryptographers, and sovereign communities. 
+
+More importantly, it has evolved from a 1:1 private messenger into a platform for **sovereign publishing and broadcast channels**. Platforms like Telegram banned tens of millions of channels in 2025 alone, proving to creators and communities that they do not own their audience on centralized platforms. On SimpleX channels, publishers cannot be revoked, subscribers cannot be tracked, and content cannot be taken down centrally.
+
+### Why the Commercial Model Works: Scale, Low ARPU, and Organic Demand
+
+A common criticism of privacy tools is that they make great philosophical statements but terrible businesses. 
+
+I take the opposite view for two reasons:
+
+1. **Unsolicited willingness to pay:** Before SimpleX even introduced paid commercial tiers, users voluntarily gave over **$650,000 in unsolicited donations**. When a community gives you hundreds of thousands of dollars purely to support the software, you have a level of organic product love and willingness to pay that most consumer startups spend tens of millions of venture dollars trying to manufacture.
+2. **Viral dynamics and low ARPU:** Messaging apps are inherently viral networks. Once a protocol achieves scale, building a high-margin, profitable business is straightforward even at very low average revenue per user (ARPU).
+
+SimpleX is not monetizing through surveillance advertising. It is monetizing through core infrastructure utilities:
+* **SimpleX Domains (`.simplex` public names launching Dec 12):** Memorable names for public channels and contact addresses, providing recurring utility revenue.
+* **Paid Supporter Badges and Dedicated Relays:** High-throughput infrastructure for power users and enterprise teams.
+* **Enterprise Messaging:** Allowing businesses to talk to customers via their websites, without any privacy compromises of existing solutions like Intercom or Drift (especially important for sectors that require anonymity by law).
+
+### Why I Doubled Down, and Why You Should Join the Wefunder Round
+
+Messaging is the most fundamental layer of human communication on the internet. It should look more like email: an open, decentralized protocol that nobody owns, rather than a walled garden controlled by Big Tech.
+
+When Evgeny opened an insider round in mid-2026, I immediately wrote another check. And when he decided to take this round to **Wefunder** ([wefunder.com/simplexchat](https://wefunder.com/simplexchat?utm_source=nr_post)), I was proud to represent the community of investors backing him.
+
+In startup investing, you back two things: **the founder and the TAM**.
+
+The market for private, sovereign communications is enormous. And Evgeny is the rarest kind of founder: technically brilliant, relentlessly honest, and stubborn enough to see an audacious mission through to the end.
+
+If you believe that the future of communication should belong to individuals rather than centralized platforms, I encourage you to join us as an investor.
+
+👉 **Invest in SimpleX Chat on Wefunder:** [wefunder.com/simplexchat](https://wefunder.com/simplexchat?utm_source=nr_post)
+
+*(Note: Anyone investing $500 or more before September 22 secures their `.simplex` public name for 7 years prior to the public launch.)*
diff --git a/blog/20260919-simplex-supporter-badges.html b/blog/20260919-simplex-supporter-badges.html
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+++ b/blog/20260919-simplex-supporter-badges.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/blog/20260919-simplex-supporter-badges.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/blog/20260919-simplex-supporter-badges.md b/blog/20260919-simplex-supporter-badges.md
new file mode 100644
index 0000000000..b568be9297
--- /dev/null
+++ b/blog/20260919-simplex-supporter-badges.md
@@ -0,0 +1,55 @@
+# SimpleX Supporter Badges — Send Larger Files That Stay Available Longer, Without Being Identified
+
+**Published:** Sep 19, 2026
+
+You can now support SimpleX Chat and get a supporter badge, larger files and longer file storage — from v7.1 beta[^beta]. Watch <a href="https://youtu.be/7D1tI5sQWFU" target="_blank">how to buy a badge</a>.
+
+## A paid feature that cannot identify you
+
+<img src="./images/20260919-phone-supporter.png" width="19%" class="float-to-right dark:hidden">
+<img src="./images/20260919-phone-supporter-light.png" width="19%" class="float-to-right hidden dark:block">
+
+A supporter badge is shown on your profile to your contacts, group members and channel subscribers. With a badge you can send files up to 2GB, or 5GB with a legend badge, instead of 1GB, and servers keep your files for longer — 7 days with a supporter badge and 21 days with a legend badge.
+
+A badge is an anonymous credential stored in your profile on your device. The credential itself is not sent to anyone: to show the badge to a contact or to present it to a server, the app generates a new zero-knowledge proof that reveals only the badge type and the expiry date, and no two proofs can be linked to each other or to the purchase, by the badge service, your contacts or servers. Credentials are issued for one month at a time, and all badges expire on the same day of the week, so a badge places you among all supporters of that week and nothing more.
+
+This is only possible because the network has no user identifiers — in other messengers a paid feature is attached to the account, so the operator knows who paid and what they do with the feature.
+
+Read more about badges in the [whitepaper](https://github.com/simplex-chat/simplex-chat/blob/master/docs/protocol/badges-overview.md): what they grant, how they are issued and presented, and their privacy and security model.
+
+## How to get a badge
+
+<a href="https://youtu.be/7D1tI5sQWFU" target="_blank"><img src="./images/20260919-buy-badge.jpg" width="40%" class="float-to-right"></a>
+
+Buy a code on [simplex.chat/badges](https://simplex.chat/badges/), paying by card, Bitcoin or Monero, and redeem it in the app: open Settings, tap **Supporter perks**, and enter the code. The badge appears on your profile. The badge does not renew by itself, and no account is created.
+
+The v7.1 release will add purchases in the app: via the app store, or by card or cryptocurrency if you downloaded the app from GitHub or F-Droid.
+
+## What badges will do next
+
+The same mechanism will be used for other resources that cost the network more than the default. Two uses are coming:
+
+- **Backups.** A backup will be a link whose content the app updates in place, so the same link restores the latest state. A badge will extend how long the backup is kept on the servers — that is, how long the app can stay offline before the backup is lost.
+- **Better limits on servers.** Servers that verify the badge will apply higher rate limits for creating messaging queues, uploading file chunks, and registering notification tokens.
+
+## Community Crowdfunding
+
+<a href="https://wefunder.com/simplex.chat?utm_source=blog"><img src="./images/20260819-wefunder.jpg" width="40%" class="float-to-right"></a>
+
+Investors in our [equity crowdfunding on Wefunder](https://wefunder.com/simplex.chat?utm_source=blog) receive badges as perks:
+
+| Investment | Badge |
+|---|---|
+| $100 | supporter, 1 month |
+| $250 | supporter, 3 months |
+| $1,000 | supporter, 12 months, or legend, 1 month |
+| $2,500 | supporter, 12 months, or legend, 3 months |
+| $10,000 | legend, 12 months |
+
+If you invest $500 or more by November 22, you will also receive [a public SimpleX name](https://simplex.domains?utm_source=blog) for 5 years[^name].
+
+Learn more and invest on Wefunder: [https://wefunder.com/simplex.chat](https://wefunder.com/simplex.chat?utm_source=blog)
+
+[^name]: Investors of $500 or more by September 22 receive a name for 7 years, and after November 22 for 3 years — ahead of the public launch of names on December 12.
+
+[^beta]: v7.1 beta is available via [Play Store](https://play.google.com/store/apps/details?id=chat.simplex.app) (Android beta), [TestFlight](https://testflight.apple.com/join/DWuT2LQu) (iOS), our [F-Droid repo](https://simplex.chat/fdroid/) and [GitHub](https://github.com/simplex-chat/simplex-chat/releases) (Android and desktop).
diff --git a/blog/index.html b/blog/index.html
index 5bfc882ad1..e610303ef1 100644
--- a/blog/index.html
+++ b/blog/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/blog.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -2469,17 +2473,7 @@ and why this move feels like an essential learning opportunity.</p>
         
         
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-double-ratchet-algorithm" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Double ratchet algorithm</h4><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="double-ratchet-algorithm">Read more</button></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-double-ratchet-algorithm" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Double ratchet algorithm</h4><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="double-ratchet-algorithm">Read more</button></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/contact.md b/contact.md
new file mode 100644
index 0000000000..ecf1706558
--- /dev/null
+++ b/contact.md
@@ -0,0 +1,66 @@
+# You received an address to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received an address to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
diff --git a/contact/index.html b/contact/index.html
index c560415fa3..682f8e8a4f 100644
--- a/contact/index.html
+++ b/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received an address to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/credits.md b/credits.md
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+# SimpleX Crowdfunding to Build Community Credits: Strategy & Vision
+
+<a href="javascript:void(0);" data-show-overlay="mint-simplex-nft" class="open-overlay-btn"><img src="/img/design_3/simplex_nft_smpx.jpg" width="200" class="float-to-right" style="border-radius: 10px;"></a>
+
+SimpleX is a private and secure messaging network without user IDs where you own your identity, contacts, groups, and content — there are no ads, no tracking, and no central authority. It relies on open protocols and open-source code, enabling anyone to audit the code and to create alternative apps and servers. No single entity can control it.
+
+To scale for large groups and channels, without relying on any single entity, network needs a sustainable way to fund servers.
+
+Take money from advertisers and you become a surveillance company. Take money from a single large investor and you hand them the kill switch. Community Credits offer the solution — they are prepaid infrastructure credits for servers used by groups and channels.
+
+These credits are not tradable tokens or speculative assets — there will be no pre-sale or emission. It's a method to pay directly for the network infrastructure while maintaining privacy.
+
+## Crowdfunding to Build Community Credits
+
+Building Community Credits requires more capital than we have. So we will raise capital in the same way we designed the network: decentralized, community-funded, with no single point of capture. If you use SimpleX, you can own part of what you already help build. The crowdfunding is now live — you can [invest in SimpleX Chat](https://simplex.chat/crowdfunding/), and join [SimpleX Crowdfunding News](https://simplex.chat/crowdfunding-news/) for updates.
+
+## Why Community Credits?
+
+To pay for network infrastructure securely and privately.
+
+With "free" centralized platforms:
+- you lose security and privacy, because your data is used for advertising and sold.
+- they de-platform inconvenient users, often based on frivolous complaints.
+- you don't own all rights to your content.
+
+Paying for server capacity may be cheaper than "free" platforms.
+
+## How Will It Work?
+
+In short:
+
+<img src="/img/design_3/community_vouchers_light.jpg" width="38%" class="float-to-right dark:hidden">
+
+<img src="/img/design_3/community_vouchers_dark.jpg" width="38%" class="float-to-right hidden dark:block">
+
+- Buy Community Credits. Initially you would pay with a stablecoin (USDT/USDC). The goal is to allow using other popular cryptocurrencies (BTC/ETH/XMR) and also in-app payments - to make direct usage of blockchain optional for the end users.
+
+- Funds are locked in an autonomous smart contract not controlled by SimpleX Chat company or by anybody else.
+
+- Assign Community Credits to a group or channel you want, using its public address. This assignment is private, and group owners or server operators won't be able to link it to the purchase, thanks to zero-knowledge proofs.
+
+- Group or channel owners redeem the Credits to the server operators they use. The redemption is also private, and not linkable to the assignment or purchase.
+
+- Server operators receive up to 70% of the unlocked funds, with the rest being allocated to network development and governance.
+
+## Why Blockchain?
+
+It's the only way to make SimpleX network truly decentralized and secure:
+
+- Group and user names resistant to man-in-the-middle attacks.
+
+- Public registry of network operators, with their trust scores.
+
+- Private and secure payments based on zero-knowledge proofs in smart-contracts.
+
+We are currently evaluating several popular blockchains that have strong support for zero-knowledge proofs - technology that supports private operations on public blockchains.
+
+## Timeline & How to Get Involved
+
+**2025-26**:
+- evaluating blockchains,
+- drafting Community Credits whitepaper about system and cryptography design for Community Credits.
+- development of large groups and communities.
+
+We welcome your feedback on this proposal and any in-progress design documents.
+
+**2026-27**:
+- launch support for large groups and channels.
+- test version of Community Credits.
+- SimpleX network namespace v1.
+
+**Join in**:
+- Create a small group or channel using today's tech, and get it added to our experimental directory of groups.
+- Talk to us if you want to be a server operator to earn revenue and about any partnerships.
+
+## Community Credits FAQ
+
+**Will self-hosted servers still work?**
+
+Yes! Support for self-hosted servers will be improved, and they can be used together with paid servers, for better reliability and censorship-resistance.
+
+**Why not just use existing cryptocurrency?**
+
+Cryptocurrencies are:
+- Speculative and volatile.
+- Regulated as financial transactions.
+- BTC and XMR blockchains do not support smart contract logic, e.g. for locked funds.
+
+**How can it be private on a public blockchain?**
+
+High level of privacy is achieved by new address per purchase, proxied access to blockchain, and zero-knowledge proofs that make payment and usage unlinkable.
+
+**Can I sell or transfer Credits?**
+
+No, Community Credits cannot be sold or transferred. Once purchased and assigned to a group or channel, they can only be redeemed to server operators. They will expire in 12 months if not redeemed, with the funds released to network development and governance.
+
+**Free messaging limits?**
+
+Private chats and small groups remain free within fair use (up to 128 undelivered messages per contact, with up to 21 days storage, up to 1GB files stored for 2 days). Community Credits will be used to pay for large groups infrastructure and for memorable public names.
+
+**Who controls the smart contracts?**
+
+We will control them during testing. Once released for general access, the contracts that accept and hold funds will be autonomous and immutable.
+
+**How is revenue share of server operators determined?**
+
+Server operators will receive up to 70% of the infrastructure payments. A higher share will be allocated for:
+- identified operators, because knowing who runs the servers achieves better user privacy and security,
+- more reliable servers,
+- servers that operated for a longer time.
+
+**What is the technology design?**
+
+[The conceptual design](https://github.com/simplex-chat/simplex-chat/blob/master/docs/rfcs/2025-12-10-vouchers-2.md) for Community Credits uses zero-knowledge proofs, making the purchase, assigning credits to groups and their redemptions unlinkable.
+
+A whitepaper will be published in June 2026.
+
+
+## Disclaimer
+
+This design is evolving — please share your feedback.
+
+This is not an investment offer. All details are subject to legal review.
diff --git a/credits/index.html b/credits/index.html
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--- a/credits/index.html
+++ b/credits/index.html
@@ -57,6 +57,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg" />
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/credits.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/crowdfunding-news.md b/crowdfunding-news.md
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+# SimpleX Crowdfunding News
+
+The news about SimpleX Chat equity crowdfunding on Wefunder, published as a SimpleX channel. Join it in the SimpleX Chat app: [SimpleX Crowdfunding News](https://smp10.simplex.im/c#q09nMBmWFGz1m2TvgfZFaEOG5D2a7Ma9mSkl6pHXEsg). The crowdfunding memo: [simplex.chat/wefunder.md](https://simplex.chat/wefunder.md).
+
+Recent posts in JSON, with the channel profile and subscriber count, from any of the channel relays: [relay2.simplex.chat](https://relay2.simplex.chat/channel/JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI=.json), [relay3.simplex.chat](https://relay3.simplex.chat/channel/JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI=.json).
diff --git a/crowdfunding-news/index.html b/crowdfunding-news/index.html
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+        
+<link rel="alternate" type="text/markdown" href="/crowdfunding-news.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
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-        <html><head></head><body><div data-simplex-channel-preview="" data-channel-link="https://smp10.simplex.im/c#q09nMBmWFGz1m2TvgfZFaEOG5D2a7Ma9mSkl6pHXEsg" data-channel-id="JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI=" data-relay-domains="relay2.simplex.chat,relay3.simplex.chat" data-app-download-buttons="off" data-color-scheme="site" data-top-offset="54"></div>
+        <div data-simplex-channel-preview
+    data-channel-link="https://smp10.simplex.im/c#q09nMBmWFGz1m2TvgfZFaEOG5D2a7Ma9mSkl6pHXEsg"
+    data-channel-id="JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI="
+    data-relay-domains="relay2.simplex.chat,relay3.simplex.chat"
+    data-app-download-buttons="off"
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+></div>
+<template data-markdown>
+<p>The news about SimpleX Chat equity crowdfunding on Wefunder, published as a SimpleX channel. Join it in the SimpleX Chat app: <a href="https://smp10.simplex.im/c#q09nMBmWFGz1m2TvgfZFaEOG5D2a7Ma9mSkl6pHXEsg">SimpleX Crowdfunding News</a>. The crowdfunding memo: <a href="/wefunder.md">simplex.chat/wefunder.md</a>.</p>
+<p>Recent posts in JSON, with the channel profile and subscriber count, from any of the channel relays: <a href="https://relay2.simplex.chat/channel/JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI=.json">relay2.simplex.chat</a>, <a href="https://relay3.simplex.chat/channel/JDGvcD7DI4q8LPH1gGpG2MVHj6wdrETfbhl0ARVYJYI=.json">relay3.simplex.chat</a>.</p></template>
 <script src="/js/channel-preview.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/crowdfunding.md b/crowdfunding.md
new file mode 100644
index 0000000000..35beba63df
--- /dev/null
+++ b/crowdfunding.md
@@ -0,0 +1,168 @@
+# The only messaging network without any user identifiers
+
+SimpleX Chat is building a messaging network unlike every major platform — without phone numbers, usernames, emails, or user accounts.
+
+[Invest on Wefunder](https://wefunder.com/simplex.chat?utm_source=landing) [Subscribe for updates](https://simplex.chat/crowdfunding/#request)
+
+The full crowdfunding memo, in Markdown for AI assistants: [simplex.chat/wefunder.md](https://simplex.chat/wefunder.md)
+
+**3M**Downloads
+
+**600K**Monthly users
+
+[Subscribe for updates](https://simplex.chat/crowdfunding/#request)
+
+## Over 600,000 monthly users
+
+Organic growth: hundreds of user posts, podcasts and videos, and $650,000 in user donations, before any paid features.
+
+Only $1.7M investment over 4 years — more capital efficient than most startups.
+
+## Every other network can identify you
+
+Surveillance, censorship and online crime all depend on user identifiers. AI made all three affect everyone.
+
+Removing them by design, as SimpleX did, is the only solution — so you control who can reach you.
+
+[Why AI increases demand for privacy](https://simplex.chat/crowdfunding/#ai-privacy)
+
+Users
+
+**600,000** active monthly,
+
+organic growth
+
+Creators
+
+**1,000s** of public
+
+groups and channels
+
+Businesses
+
+**50+** offer customer
+
+support
+
+Developers
+
+**19K+** GitHub stars
+
+**1,000+** forks, bots,
+
+bridges, plugins
+
+Operators
+
+**~1,000**
+
+independent
+
+servers
+
+## SimpleX is a network, not an app
+
+All five kinds of users arrived on their own — the cold start problem solved.
+
+Each group makes the network more valuable to others, accelerating growth.
+
+## Pre-revenue stage ends this year
+
+Additional file capacity and SimpleX public names launch this year, followed by business messaging and paid servers for big channels.
+
+Demand is proven — users donated $650,000 while everything was free.
+
+## Design advantage that can't be copied
+
+Only SimpleX has every property in this comparison — together they need a network without user identifiers.
+
+A network with user IDs can't remove them — rivals would have to rebuild, and the ad giants would lose revenue that depends on user IDs.
+
+## A network others build on
+
+Developers already built many different services on SimpleX. In 2027, we plan to add support for user-created features inside chats.
+
+Features and services users build would bring new users and increase revenue.
+
+[How custom UX helps unify messaging](https://simplex.chat/crowdfunding/#one-protocol)
+
+# Get a stake in SimpleX Chat
+
+We are building a network that people own.
+We invite you to invest and become part of it.
+
+[Invest on Wefunder](https://wefunder.com/simplex.chat?utm_source=landing) [Subscribe for updates](https://simplex.chat/crowdfunding/#request)
+
+Invest $500+ during early bird terms and get a SimpleX public name for your channel or business for 5 years, ahead of public launch.
+
+This Regulation Crowdfunding offering is made available through Wefunder Portal LLC. This investment involves a high degree of risk, including the possible loss of your investment.
+
+[SimpleX Chat](https://simplex.chat/) [Privacy policy](https://simplex.chat/privacy) [Wefunder](https://wefunder.com/simplex.chat?utm_source=landing)
+
+[Invest on Wefunder](https://wefunder.com/simplex.chat?utm_source=landing)
+
+[Close](https://simplex.chat/crowdfunding/#identifiers)
+
+[Close](https://simplex.chat/crowdfunding/#identifiers)
+
+## AI increases demand for privacy
+
+Surveillance, deplatforming, and online fraud used to require human effort, so they were relatively rare — and most people thought they needed no protection.*
+
+AI removed the effort: it scans messages at scale, deplatforms automatically, and can fake any face, voice, or number. Anyone with a user identifier will now be targeted — so everyone will want protection.
+
+AI agents handling credentials and money increase demand further: an agent whose identity is controlled by a platform can be shut down or turned against its owner.
+
+**Everyone will want communication without user identifiers — and only SimpleX network can provide it.**
+
+* In 2021, 9% of 16+ year old US residents were victims of identity theft — [Bureau of Justice Statistics](https://bjs.ojp.gov/library/publications/victims-identity-theft-2021).
+
+[Close](https://simplex.chat/crowdfunding/#identifiers)
+
+[Close](https://simplex.chat/crowdfunding/#identifiers)
+
+## AI made everyone a target
+
+For 150 years, every network required a user identifier to reach you — a phone number, a username, or a key.
+
+This identifier is your fixed address that can be used to surveil, deplatform, or attack you. AI made it automatic and cheap, so everyone is affected now. SimpleX has no user identifiers at all, so users are protected from such attacks — it is the only network built this way.
+
+The AI agents now acting for people need the same — an identity no company can control, on a network without any user identifiers.
+
+[Close](https://simplex.chat/crowdfunding/#!)
+
+[Close](https://simplex.chat/crowdfunding/#!)
+
+## Subscribe for SimpleX Chat updates
+
+We will send the deck and updates about the crowdfunding.
+
+[Or connect to our team via SimpleX Chat](https://smp11.simplex.im/a#JxGcOA1_QhlmVFzYYabloMbvMZk5Y9d9iS3ITDnhzYo)
+
+We use Mailchimp to send emails.
+
+[Close](https://simplex.chat/crowdfunding/#!)
+
+[Close](https://simplex.chat/crowdfunding/#!)
+
+## Thank you for your interest in SimpleX Chat crowdfunding
+
+Please confirm your subscription by clicking the link in the email.
+
+This address is in the list — you will receive the updates.
+
+We could not confirm your subscription — Mailchimp’s response is below.
+
+[Download pitch deck](https://simplex.chat/img/crowdfunding/simplex-chat-pitch-deck.pdf)
+
+[Close](https://simplex.chat/crowdfunding/#build)
+
+[Close](https://simplex.chat/crowdfunding/#build)
+
+## How custom UX helps unify messaging
+
+Every network before messaging converged to one protocol — telephony, email, the web.
+
+Messaging is the exception, because each app's experience can't be reduced to a shared protocol.
+
+**Once we add custom user experiences in the chat, SimpleX might become the network messaging converges on.**
diff --git a/crowdfunding/index.html b/crowdfunding/index.html
index 576cf0b42c..c2b906e6b5 100644
--- a/crowdfunding/index.html
+++ b/crowdfunding/index.html
@@ -13,6 +13,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg" />
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/crowdfunding.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#050920">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -1070,7 +1074,7 @@
                 <div class="cf-hero-text">
                     <h1>The only<br>messaging network<br>without any <br class="cf-br-narrow">user identifiers</h1>
                     <p class="lead">SimpleX Chat is building a messaging network unlike every major platform &mdash; without phone numbers, usernames, emails, or user accounts.</p>
-                    <p class="lead lead-short">No phone numbers, emails, or accounts.</p>
+                    <p class="lead lead-short" data-markdown-skip>No phone numbers, emails, or accounts.</p>
                     <div class="cf-hero-cta">
                         <a class="cf-pill cf-primary" id="cf-hero-invest" href="https://wefunder.com/simplex.chat?utm_source=landing" target="_blank" rel="noopener" aria-label="Invest on Wefunder">
                             Invest on <svg width="120" height="33" viewBox="0 0 165 45" fill="none" xmlns="http://www.w3.org/2000/svg" aria-hidden="true">
@@ -1080,6 +1084,7 @@
                         </a>
                         <a class="cf-cta-link" id="cf-hero-subscribe" href="#request">Subscribe for updates</a>
                     </div>
+                    <template data-markdown><p>The full crowdfunding memo, in Markdown for AI assistants: <a href="/wefunder.md">simplex.chat/wefunder.md</a></p></template>
                     <div class="cf-stats">
                         <div class="cf-stat">
                             <img src="/img/crowdfunding/cloud-download.png" alt="">
diff --git a/cs/contact.md b/cs/contact.md
new file mode 100644
index 0000000000..f1e50d5f6f
--- /dev/null
+++ b/cs/contact.md
@@ -0,0 +1,65 @@
+# Byl vám zaslán odkaz pro připojení na SimpleX Chat
+
+## Naskenujte QR kód pomocí aplikace SimpleX Chat na svém telefonu nebo tabletu.
+
+Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+
+Ještě jste si nestáhli SimpleX Chat?
+
+Ke stažení aplikace použijte níže uvedené odkazy.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Naskenujte QR kód z mobilní aplikace
+
+# Byl vám zaslán odkaz pro připojení na SimpleX Chat
+
+K vytvoření připojení:
+
+Instalace aplikace SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid)
+
+1
+
+Se připojit v aplikaci
+
+Otevřete aplikaci SimpleX
+
+2
+
+Klepněte na tlačítko "připojit" v aplikaci
+
+3
+
+## Naskenujte QR kód pomocí aplikace SimpleX Chat
+
+Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+
+## Instalace SimpleX chat do terminálu
+
+Použijte tento příkaz:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Viz SimpleX Chat GitHub repozitář Pro návod, jak stáhnout nebo zkompilovat ze zdrojového kódu.
+
+---
+
+## Pokud jste již nainstalovali SimpleX Chat pro terminál
+
+Pokud jste již nainstalovali SimpleX Chat pro terminál v1.0.0+, Zkopírujte níže uvedený příkaz a použijte jej v chatu:
+
+## Připojit SimpleX
+
+Zveme vás k účasti na konverzaci
+
+[Připojte se ke komunitě REDDIT](https://www.reddit.com/r/SimpleXChat/) [Připojte se k nám na GitHubu](https://github.com/simplex-chat) [Přispějte zde a pomozte nám](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Přihlaste se k odběru novinek
+
+---
+
+Získat SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid)
diff --git a/cs/contact/index.html b/cs/contact/index.html
index 2aab58d6f7..649ca2a668 100644
--- a/cs/contact/index.html
+++ b/cs/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Byl vám zaslán odkaz pro připojení na SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Naskenujte QR kód pomocí aplikace SimpleX Chat na svém telefonu nebo tabletu.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+                Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť &mdash; jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ještě jste si nestáhli SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Ke stažení aplikace použijte níže uvedené odkazy.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instalace aplikace SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Naskenujte QR kód pomocí aplikace SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+                            Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť &mdash; jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalace SimpleX chat do terminálu</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repozitář</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Pokud jste již nainstalovali SimpleX Chat pro terminál</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Přihlaste se k odběru novinek</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="vložte svou e-mailovou adresu">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Získat SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/cs/fdroid.md b/cs/fdroid.md
new file mode 100644
index 0000000000..15ed10a819
--- /dev/null
+++ b/cs/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat přes F-Droid
+
+### SimpleX Chat repozitář
+
+Stabilní a beta verze vytvořené vývojáři
+
+Chcete-li jej přidat do vašeho F-Droid clienta, naskenujte QR kód nebo použijte tuto adresu URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Otisk podpisového klíče (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repozitář
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stabilní verze vytvořené F-Droid.org
+
+Vydání v tomto repozitáři se provádí o několik dní později.
+
+SimpleX Chat a F-Droid.org repozitáře jsou podepsané různými klíči. Chcete-li mezi nimi přejít, prosím [exportujte](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) chat databázi a přeinstalujte aplikaci.
diff --git a/cs/fdroid/index.html b/cs/fdroid/index.html
index e202ae8931..7e2b96e43a 100644
--- a/cs/fdroid/index.html
+++ b/cs/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat přes F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stabilní a beta verze vytvořené vývojáři</p>
                         <p>Chcete-li jej přidat do vašeho F-Droid clienta, <span class="hide-on-mobile">naskenujte QR kód nebo</span> použijte tuto adresu URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Otisk podpisového klíče (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repozitář</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stabilní verze vytvořené F-Droid.org</p>
                 <p class="mb-2">Vydání v tomto repozitáři se provádí o několik dní později.</p>
                 <p class="mb-2">SimpleX Chat a F-Droid.org repozitáře jsou podepsané různými klíči. Chcete-li mezi nimi přejít, prosím <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exportujte</a> chat databázi a přeinstalujte aplikaci.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/cs/file.md b/cs/file.md
new file mode 100644
index 0000000000..067e72c77e
--- /dev/null
+++ b/cs/file.md
@@ -0,0 +1,31 @@
+# SimpleX Přenos Souborů
+
+Přetáhněte soubor sem
+
+nebo
+
+Vyberte soubor
+
+Max. 100 MB - [SimpleX Chat aplikace](https://simplex.chat/downloads) podporuje soubory do 1 GB
+
+Odeslání souborů bezpečně s šifrováním end-to-end — žádné účty, žádné sledování.
+
+## Získejte SimpleX Chat — nejbezpečnější & soukromí komunikátor
+
+Přenos souborů, který jste právě použili, používá stejný protokol pro přenos dat jako SimpleX Chat. Aplikace má end-to-end šifrované zprávy, hlasové a video volání, skupiny a odesílání souborů. Žádný účet. Žádný telefon. Žádný e-mail. Žádné ID uživatelského profilu.
+
+# XFTP protokol: nejbezpečnější přenos souborů
+
+### Není nutný žádný účet
+
+Každá část souborů používá nový náhodný klíč. Datové směrovače nemají "uživatele" nebo "soubory" - přenášejí šifrované části souborů stejných velikostí.
+
+### Trojitě zašifrováno ve vašem prohlížeči
+
+Šifrovací klíč souboru je obsažen pouze v části hash adresy URL – váš prohlížeč jej nikdy neodesílá na server. Existují 3 úrovně šifrování: přenos přes protokol TLS, šifrování pro každého příjemce (jedinečný dočasný klíč pro každý přenos) a end-to-end šifrování souborů.
+
+### Nezávislé směrovače dat
+
+Když je soubor rozdělen na části, je odeslán přes síťové směrovače provozované nezávislými stranami. Žádný operátor nemůže vidět aktuální velikost nebo jméno souboru. I kdyby byl směrovač ohrožen, může vidět pouze šifrované části s pevně stanovenou velikosti. Části souboru jsou v mezipaměti síťových směrovačů uchovávány přibližně 48 hodin.
+
+[Přečtěte si specifikaci XFTP protokolu →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/cs/file/index.html b/cs/file/index.html
index 752d9c322c..5d16654297 100644
--- a/cs/file/index.html
+++ b/cs/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">SimpleX Přenos Souborů</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Přetáhněte soubor sem</p>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Získejte SimpleX Chat — nejbezpečnější &amp; soukromí komunikátor
+      Získejte SimpleX Chat &mdash; nejbezpečnější &amp; soukromí komunikátor
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       Přenos souborů, který jste právě použili, používá stejný protokol pro přenos dat jako SimpleX Chat. Aplikace má end-to-end šifrované zprávy, hlasové a video volání, skupiny a odesílání souborů. Žádný účet. Žádný telefon. Žádný e-mail. Žádné ID uživatelského profilu.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/cs/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/cs/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/cs/index.html b/cs/index.html
index 978bc8ca81..f712960449 100644
--- a/cs/index.html
+++ b/cs/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/cs/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/cs/fdroid" title="Stáhnout aplikaci SimpleX přes F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Beta verze SimpleX pro iOS na TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Beta verze SimpleX pro iOS na TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Bezpečnostní audity" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Nyní</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Červen 2027</span>
diff --git a/cs/index.md b/cs/index.md
new file mode 100644
index 0000000000..aa6f8323bb
--- /dev/null
+++ b/cs/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Žijte svobodně
+
+## Ve Své Síti
+
+První síť bez uživatelských ID.
+Vaše kontakty, skupiny a kanály patří vám.
+
+Invest in SimpleX Chat. [Další informace.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [Stáhnout aplikaci SimpleX přes F-Droid](https://simplex.chat/cs/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Bezpečnostní audity](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Bezpečnostní
+audity
+
+[Doporučení messengerů od Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [doporučení messengerů od Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publikace Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Rezence od Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Rozhovor v podcastu OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nikdo nevidí, s kým komunikujete
+
+Ani servery – všechny zprávy vypadají jako náhodný šum.
+
+Každý den je soukromě doručeno desítky milionů zpráv.
+
+[Zjistit více o zprávách v SimpleX](https://simplex.chat/cs/messaging)
+
+## Síť je vaše
+
+Každý kontakt a skupina jsou na vašem zařízení, ne v databázi serveru.
+
+Síť nekontroluje žádný subjekt – servery může provozovat kdokoli.
+
+[Proč ji vyvíjíme](https://simplex.chat/cs/why)
+
+## Financováno uživateli
+
+Pro zachování nezávislosti budou velké kanály a komunity platit za své servery.
+
+A uživatelé nyní mohou investovat do SimpleX Chat — crowdfunding je spuštěn!
+
+[Investovat do SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Plán SimpleX ke svobodnému internetu
+
+2026
+
+: Škálování pro velké komunity
+
+Odchod od centralizovaných platforem
+
+Červen 2027
+
+: Udržitelné komunity a servery
+
+Spuštění Community Credits
+
+Prosinec 2027
+
+: Pomozte své komunitě růst
+
+Nástroje na podporu vašich komunit
+
+[Uživatelské skupiny SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Zapojte se do komunit SimpleX
+
+Více než 2 miliony lidí si stáhly aplikace SimpleX.
+
+Najděte své kanály a komunity v katalogu a vytvořte si vlastní!
+
+[Zobrazit katalog SimpleX](https://simplex.chat/directory)
diff --git a/cs/invitation.md b/cs/invitation.md
new file mode 100644
index 0000000000..f1e50d5f6f
--- /dev/null
+++ b/cs/invitation.md
@@ -0,0 +1,65 @@
+# Byl vám zaslán odkaz pro připojení na SimpleX Chat
+
+## Naskenujte QR kód pomocí aplikace SimpleX Chat na svém telefonu nebo tabletu.
+
+Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+
+Ještě jste si nestáhli SimpleX Chat?
+
+Ke stažení aplikace použijte níže uvedené odkazy.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Naskenujte QR kód z mobilní aplikace
+
+# Byl vám zaslán odkaz pro připojení na SimpleX Chat
+
+K vytvoření připojení:
+
+Instalace aplikace SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid)
+
+1
+
+Se připojit v aplikaci
+
+Otevřete aplikaci SimpleX
+
+2
+
+Klepněte na tlačítko "připojit" v aplikaci
+
+3
+
+## Naskenujte QR kód pomocí aplikace SimpleX Chat
+
+Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+
+## Instalace SimpleX chat do terminálu
+
+Použijte tento příkaz:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Viz SimpleX Chat GitHub repozitář Pro návod, jak stáhnout nebo zkompilovat ze zdrojového kódu.
+
+---
+
+## Pokud jste již nainstalovali SimpleX Chat pro terminál
+
+Pokud jste již nainstalovali SimpleX Chat pro terminál v1.0.0+, Zkopírujte níže uvedený příkaz a použijte jej v chatu:
+
+## Připojit SimpleX
+
+Zveme vás k účasti na konverzaci
+
+[Připojte se ke komunitě REDDIT](https://www.reddit.com/r/SimpleXChat/) [Připojte se k nám na GitHubu](https://github.com/simplex-chat) [Přispějte zde a pomozte nám](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Přihlaste se k odběru novinek
+
+---
+
+Získat SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/cs/fdroid)
diff --git a/cs/invitation/index.html b/cs/invitation/index.html
index c3cc38eb12..9bf111e8a6 100644
--- a/cs/invitation/index.html
+++ b/cs/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Byl vám zaslán odkaz pro připojení na SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Naskenujte QR kód pomocí aplikace SimpleX Chat na svém telefonu nebo tabletu.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+                Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť &mdash; jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ještě jste si nestáhli SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Ke stažení aplikace použijte níže uvedené odkazy.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instalace aplikace SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Naskenujte QR kód pomocí aplikace SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť — jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
+                            Veřejné klíče a adresa fronty zpráv v tomto odkazu NEJSOU při zobrazení této stránky odesílány přes síť &mdash; jsou obsaženy ve fragmentu kontrolního součtu adresy URL odkazu.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalace SimpleX chat do terminálu</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repozitář</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Pokud jste již nainstalovali SimpleX Chat pro terminál</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Přihlaste se k odběru novinek</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="vložte svou e-mailovou adresu">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Získat SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/cs/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/cs/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/cs/messaging.md b/cs/messaging.md
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--- /dev/null
+++ b/cs/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Proč je SimpleX jedinečný
+
+### Máte naprosté soukromí
+
+SimpleX chrání soukromí vašeho profilu, kontaktů a metadat a skrývá je před servery SimpleX sítě a jakýmikoli pozorovateli.
+
+Na rozdíl od jakékoli jiné existující síti pro zasílání zpráv nemá SimpleX žádné identifikátory přiřazené uživatelům — **ani náhodná čísla**.
+
+### Jste chráněni před spamem a zneužitím
+
+Protože na SimpleX síti nemáte žádný identifikátor nebo pevnou adresu, nikdo vás nemůže kontaktovat pokud nenasdílíte jednorázovou nebo dočasnou uživatelskou adresu, jako QR kód nebo odkaz.
+
+### Vy kontrolujete vaše data
+
+SimpleX Chat ukládá všechna uživatelská data pouze na klientských zařízeních pomocí **přenosného šifrovaného databázového formátu**, který lze exportovat a přenést na jakékoli podporované zařízení.
+
+End-to-end šifrované zprávy jsou dočasně uchovávány na přenosových serverech SimpleX, dokud nejsou přijaty, poté jsou trvale odstraněny.
+
+### Vlastníte síť SimpleX
+
+Síť SimpleX je plně decentralizovaná a nezávislá na jakékoli kryptoměně nebo jakékoli jiné síti než internetu.
+
+SimpleX můžete **použít s vašimi vlastními servery** nebo s námi poskytovanými servery — a přesto se připojit k libovolnému uživateli.
+
+# Úplné soukromí vaší identity, profilu, kontaktů a metadat
+
+Na rozdíl od jiných sítí pro zasílání zpráv nemá SimpleX **žádné identifikátory přiřazené uživatelům**. Nespoléhá na telefonní čísla, adresy založené na doméně (jako e-mail nebo XMPP), uživatelská jména, veřejné klíče nebo dokonce náhodná čísla k identifikaci svých uživatelů — Operátoři SimpleX serverů neví, kolik lidí používá jejich servery.
+
+K doručování zpráv SimpleX používá [párové anonymní adresy](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) jednosměrných front zpráv, oddělených pro přijaté a odeslané zprávy, obvykle přes různé servery.
+
+Tento design chrání soukromí těch, s kým komunikujete, skrývá ho před servery sítě SimpleX a před jakýmikoli pozorovateli. Pro skrytí své IP adresy před servery, můžete se **připojit k serverům SimpleX přes Tor**.
+
+# Nejlepší ochrana před spamem a zneužitím
+
+Protože na síti SimpleX nemáte žádný identifikátor, nikdo vás nemůže kontaktovat pokud nenasdílíte jednorázovou nebo dočasnou uživatelskou adresu, jako QR kód nebo odkaz.
+
+Dokonce i s volitelnou uživatelskou adresou, kterou lze použít k zasílání spamových požadavků na kontakt, ji však můžete změnit nebo úplně odstranit, aniž byste ztratili jakékoli spojení.
+
+# Vlastnictví, kontrola a zabezpečení vašich dat
+
+SimpleX Chat ukládá všechna uživatelská data pouze na klientských zařízeních pomocí **přenosného šifrovaného databázového formátu**, který lze exportovat a přenést na jakékoli podporované zařízení.
+
+End-to-end šifrované zprávy jsou dočasně uchovávány na přenosových serverech SimpleX, dokud nejsou přijaty, poté jsou trvale odstraněny.
+
+Na rozdíl od serverů federovaných sítí (e-mail, XMPP nebo Matrix) servery SimpleX neukládají uživatelské účty, pouze předávají zprávy, čímž chrání soukromí obou stran.
+
+Mezi odeslaným a přijatým provozem serveru nejsou žádné společné identifikátory ani šifrovaný text — pokud to někdo pozoruje, nemůže snadno určit, kdo s kým komunikuje, i když je TLS kompromitován.
+
+# Plně decentralizované — uživatelé vlastní síť SimpleX
+
+Můžete **použít SimpleX se svými vlastními servery** a přesto komunikovat s lidmi, kteří používají přednastavené servery v aplikacích.
+
+SimpleX síť používá [otevřený protokol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) a poskytuje [SDK k vytváření chat botů](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), což umožní implementaci služeb, díky nimž boudou moci uživatelé komunikovat prostřednictvím aplikací SimpleX Chat — Opravdu se těšíme, jaké služby SimpleX vytvoříte.
+
+Pokud uvažujete o vývoji pro SimpleX síť, například chat bot pro uživatele aplikace SimpleX nebo integraci knihovny SimpleX chat do Vasí mobilní aplikace, prosím [buďte ve spojení](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) pro jakoukoli radu a podporu.
+
+## Funkce
+
+E2E šifrované zprávy s Markdown a editací
+
+E2E šifrované
+obrázky, videa a soubory
+
+E2E-šifrované decentralizované skupiny — pouze uživatelé vědí, že existují
+
+Hlasové zprávy šifrované E2E
+
+Mizící tajné konverzace
+
+E2E šifrované
+hlasové a videohovory
+
+Přenosné šifrované úložiště aplikace — přesuňte profil do jiného zařízení
+
+režim Inkognito —
+Unikátní pro SimpleX Chat
+
+## Co dělá SimpleX soukromým
+
+### Dočasné anonymní párové identifikátory
+
+SimpleX používá dočasné anonymní párové adresy a pověření pro každého uživatele nebo člena skupiny.
+
+Umožňuje doručovat zprávy bez identifikátoru uživatelských profilů, což poskytuje lepší soukromí metadat než alternativy.
+
+### Out-of-band výměna klíčů
+
+Mnoho komunikačních sítí je zranitelných vůči útokům MITM ze strany serverů nebo poskytovatelů sítí.
+
+Aby se tomu zabránilo, aplikace SimpleX předávají jednorázové klíče mimo pásmo, když sdílíte adresu jako odkaz nebo QR kód.
+
+### 2-vrstvé end-to-end šifrování
+
+Double-ratchet protokol —
+OTR zprávy s perfect forward secrecy a obnovou po narušení.
+
+NaCL kryptobox v každé frontě, aby se zabránilo korelaci provozu mezi frontami zpráv, pokud je ohroženo TLS.
+
+### Ověření integrity zprávy
+
+Aby byla zaručena integrita, jsou zprávy postupně číslovány a obsahují kontrolní součet předchozí zprávy.
+
+Pokud je jakákoli zpráva přidána, odstraněna nebo změněna, příjemce bude upozorněn.
+
+### Další vrstva šifrování serveru
+
+Další vrstva šifrování serveru pro doručení příjemci, aby se zabránilo korelaci mezi přijatým a odeslaným serverovým provozem, pokud je protokol TLS ohrožen.
+
+### Smíchání zpráv ke snížení korelace
+
+Servery SimpleX fungují jako smíšené uzly s nízkou latencí — příchozí a odchozí zprávy mají různá pořadí.
+
+### Zabezpečený ověřený přenos TLS
+
+Pro připojení klient-server se používá pouze protokol TLS 1.2/1.3 se silnými algoritmy.
+
+Otisk serveru a vazba kanálu zabraňují útokům MITM a replay.
+
+Obnovení připojení je zakázáno, k zabránění útokům na relace.
+
+### Volitelný přístup přes Tor
+
+Pro ochranu vaší IP adresy můžete přistupovat k serverům přes Tor nebo jinou transportní překryvnou síť.
+
+Pro použití SimpleX přes Tor prosím nainstalujte [Orbot aplikaci](https://guardianproject.info/apps/org.torproject.android/) a povolte SOCKS5 proxy (nebo VPN [na iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Jednosměrné fronty zpráv
+
+Každá fronta zpráv předává zprávy v jednom směru s různými adresami pro odesílání a přijímání.
+
+Snižuje vektory útoku ve srovnání s tradičními zprostředkovateli zpráv a dostupnými metadaty.
+
+### Více vrstev odsazení obsahu
+
+SimpleX používá odsazení obsahu pro každou šifrovací vrstvu, aby zmařil útoky na velikost zprávy.
+
+Díky tomu vypadají zprávy různých velikostí pro servery a síťové pozorovatele stejně.
+
+## SimpleX Síť
+
+SimpleX Chat poskytuje nejlepší soukromí tím, že kombinuje výhody P2P a federovaných sítí.
+
+### Na rozdíl od P2P sítí
+
+Všechny zprávy se odesílají přes servery, což zajišťuje lepší soukromí metadat a spolehlivé asynchronní doručování zpráv, přičemž se zamezuje mnoha .
+
+# Srovnání s protokoly zpráv P2P
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) protokoly a aplikace pro zasílání zpráv mají různé problémy, které je činí méně spolehlivými než SimpleX, složitějšími na analýzu a zranitelnými vůči několika typům útoků.
+
+1. P2P sítě spoléhají na varianty [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) pro směrování zpráv. Tyto implementace DHT musí vyvážit záruku dodávky a latenci. SimpleX má lepší záruku doručení a nižší latenci než P2P, protože zpráva může být zároveň předávána přes několik serverů, které si příjemce vybere. V P2P sítích je zpráva předávána přes uzly *O(log N)* postupně/sekvenčně pomocí uzlů vybraných algoritmem.
+2. SimpleX, na rozdíl od většiny P2P sítí, nemá žádné globální uživatelské identifikátory jakéhokoli druhu, dokonce ani dočasné, a používá pouze dočasné párové identifikátory, které poskytují lepší anonymitu a ochranu metadat.
+3. P2P neřeší problém [MITM útoku](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) a většina existujících implementací nepoužívá out-of-band zprávy pro počáteční výměnu klíčů. SimpleX používá out-of-band zprávy nebo v některých případech již existující zabezpečená a důvěryhodná připojení pro počáteční výměnu klíčů.
+4. Implementace P2P mohou být některými poskytovateli internetu blokovány (například [BitTorrent](https://cs.wikipedia.org/wiki/BitTorrent)). SimpleX je transportně nezávislý — může pracovat přes standardní webové protokoly, např. WebSockety.
+5. Všechny známé P2P sítě mohou být zranitelné vůči [Sybil útoku](https://en.wikipedia.org/wiki/Sybil_attack), protože každý uzel je zjistitelný a síť funguje jako celek. Známá opatření ke zmírnění tohoto problému vyžadují buď centralizovanou součást, nebo drahé [prokázání práce](https://en.wikipedia.org/wiki/Proof_of_work). Síť SimpleX nemá možnost zjistitelnosti serveru, je fragmentovaná a funguje jako několik izolovaných podsítí, což znemožňuje útoky v celé síti.
+6. Sítě P2P mohou být zranitelné vůči útoku [DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), kdy klienti mohou znovu vysílat a zesílit provoz, což vede k odmítnutí služby v celé síti. SimpleX klienti pouze přenášejí provoz ze známých spojení a nemohou být zneužiti útočníkem k zesílení provozu v celé síti.
+
+---
+
+### Na rozdíl od federovaných sítí
+
+Přenosové servery SimpleX NEUKLADAJÍ uživatelské profily, kontakty a doručené zprávy, NEPŘIPOJUJÍ se k sobě a NEEXISTUJE ŽÁDNÝ adresář serverů.
+
+---
+
+### SimpleX síť
+
+servery poskytují jednosměrné fronty pro připojení uživatelů, ale nemají žádnou viditelnost grafu síťového připojení — pouze uživatelé mají.
+
+## SimpleX vysvětlení
+
+1. Co vidí uživatel
+
+2. Jak to funguje
+
+3. Co vidí servery
+
+1. Co vidí uživatel
+
+Můžete vytvářet kontakty a skupiny a vést obousměrné konverzace, stejně jako v jakémkoli jiném messengeru.
+
+Jak může pracovat s jednosměrnými frontami a bez identifikátorů profilu uživatele?
+
+2. Jak to funguje
+
+Pro každé připojení používáte dvě samostatné fronty zasílání zpráv k odesílání a přijímání zpráv prostřednictvím různých serverů.
+
+Servery předávají zprávy jednosměrně, aniž by měly úplný obraz o konverzacích nebo spojeních uživatele.
+
+3. Co vidí servery
+
+Servery mají samostatné anonymní přihlašovací údaje pro každou frontu a nevědí, ke kterým uživatelům patří.
+
+Uživatelé mohou dále zlepšit soukromí z pohledu metadat tím, že budou přistupovat k serverům skrze Tor, což zabrání korelaci podle IP adresy.
+
+## Srovnání s jinými protokoly
+
+|  |  | Signál, velké platformy | XMPP, Matrix | P2P protokoly |
+| --- | --- | --- | --- | --- |
+| Vyžaduje globální identitu | Ne - soukromý | Ano [1] | Ano [2] | Ano [3] |
+| Možnost MITM útoku | Ne - bezpečný [4] | Ano [5] | Ano | Ano |
+| Závislost na DNS | Ne - odolný | Ano | Ano | Ne |
+| Jedna nebo centralizovaná síť | Ne – decentralizovaný | Ano | Ne - federovaný [6] | Ano [7] |
+| Centrální součást nebo jiný celosíťový útok | Ne - odolný | Ano | Ano [2] | Ano [8] |
+
+---
+
+1. Založeném obvykle na telefonním čísle a v některých případech uživatelském jménu
+2. Adresy založené na DNS
+3. Veřejný klíč nebo jiné globálně jedinečné ID
+4. SimpleX relé nemůže ohrozit šifrování e2e. Ověřte bezpečnostní kód, který zmírňuje mimo pásmový útok na kanál
+5. Pokud jsou servery operátora kompromitovány. Ověřte bezpečnostní kód v Signálu a nějaké jiné aplikaci ke zmírnění
+6. Nechrání soukromí metadat uživatelů
+7. Zatímco P2P jsou distribuovány, nejsou federované — fungují jako jediná síť
+8. P2P sítě mají buď centrální autoritu, nebo může být ohrožena celá síť — [viz zde](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Porovnání bezpečnosti koncového šifrování (end-to-end) v různých messengerech
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Doplnění zpráv | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Možnost popřít autorství zprávy | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Ochrana minulých zpráv při úniku klíčů | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Bezpečnost po kompromitaci | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Dvoufaktorová výměna klíčů | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Hybridní šifrování odolné vůči kvantovým počítačům | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar zarovnává velikost zpráv na 1024 bajtů, zatímco Signal na 160 bajtů
+2. Popiratelnost se netýká komunikace mezi klientem a serverem.
+3. Použití kryptografických podpisů může oslabit popiratelnost, ale tato otázka vyžaduje další upřesnění.
+4. Podpora více zařízení může oslabit post-kompromitační bezpečnost protokolu Double Ratchet — [viz zde](https://eprint.iacr.org/2021/626.pdf).
+5. Dvoufaktorovou výměnu klíčů lze volitelně aktivovat pomocí ověření bezpečnostním kódem.
+6. Postkvantová dohoda o klíči je omezená — chrání pouze některé kroky ratchet mechanismu.
diff --git a/cs/messaging/index.html b/cs/messaging/index.html
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Máte naprosté soukromí</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jste chráněni<br>před spamem a zneužitím</h3>
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@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vy kontrolujete vaše data</h3>
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@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vlastníte síť SimpleX</h3>
                             </div>
 
@@ -1071,7 +1075,7 @@ window.addEventListener('click',(e)=>{
     SimpleX síť používá <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">otevřený protokol</a> a poskytuje <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK k vytváření chat botů</a>, což umožní implementaci služeb, díky nimž boudou moci uživatelé komunikovat prostřednictvím aplikací SimpleX Chat — Opravdu se těšíme, jaké služby SimpleX vytvoříte.
 </p>
 <p>
-    Pokud uvažujete o vývoji pro SimpleX síť, například chat bot pro uživatele aplikace SimpleX nebo integraci knihovny SimpleX chat do Vasí mobilní aplikace, prosím <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
+    Pokud uvažujete o vývoji pro SimpleX síť, například chat bot pro uživatele aplikace SimpleX nebo integraci knihovny SimpleX chat do Vasí mobilní aplikace, prosím <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">buďte ve spojení</a> pro jakoukoli radu a podporu.
 </p>
 
                         </div>
@@ -1079,68 +1083,20 @@ window.addEventListener('click',(e)=>{
                 
 
                 
-                    <div class=" max-w-[448px]"="">
-                        </a></p><div class="flex items-center justify-center"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                    <div class="max-w-[448px]">
+                        <div class="flex items-center justify-center">
                             <img class="w-full max-w-[448px] min-w-[300px] dark:hidden" src="/img/new/unique-section-4.png" alt="">
                             <img class="w-full max-w-[448px] min-w-[300px] hidden dark:block" src="/img/new/unique-section-4-dark.png" alt="">
-                        </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
                         </div>
                     </div>
                 
-
-                
-                    <div class=" max-w-[448px]"="">
-                    </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-                
-            </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+            </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
                 <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
             </svg>
-        </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-    </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+        </div>
+    </div>
 
     
 
@@ -1235,44 +1191,12 @@ window.addEventListener('click',(e)=>{
 </section>
 
 
-</a><section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-    </a><div class="container scale-100"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+<section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
+    <div class="container scale-100">
         <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Co dělá SimpleX <span class="gradient-text">soukromým</span></h2>
 
-        </a><div class="swiper private-swiper overflow-hidden px-4 py-2"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-            </a><div class="swiper-wrapper mb-16"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+        <div class="swiper private-swiper overflow-hidden px-4 py-2">
+            <div class="swiper-wrapper mb-16">
 
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
@@ -1289,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Umožňuje doručovat zprávy bez identifikátoru uživatelských profilů, což poskytuje lepší soukromí metadat než alternativy.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1307,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Aby se tomu zabránilo, aplikace SimpleX předávají jednorázové klíče mimo pásmo, když sdílíte adresu jako odkaz nebo QR kód.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1325,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL kryptobox v každé frontě, aby se zabránilo korelaci provozu mezi frontami zpráv, pokud je ohroženo TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1343,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pokud je jakákoli zpráva přidána, odstraněna nebo změněna, příjemce bude upozorněn.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1359,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Další vrstva šifrování serveru pro doručení příjemci, aby se zabránilo korelaci mezi přijatým a odeslaným serverovým provozem, pokud je protokol TLS ohrožen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1375,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Servery SimpleX fungují jako smíšené uzly s nízkou latencí — příchozí a odchozí zprávy mají různá pořadí.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1395,57 +1319,25 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Obnovení připojení je zakázáno, k zabránění útokům na relace.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
-                </a><div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
                         <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
                         <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
                     </div>
-                    </a><div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                    <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Volitelný<br>přístup přes Tor</h3>
-                        </a><div class="flex-1 py-3 flex flex-col gap-3"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                        <div class="flex-1 py-3 flex flex-col gap-3">
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pro ochranu vaší IP adresy můžete přistupovat k serverům přes Tor nebo jinou transportní překryvnou síť.</p>
                             
-                            </a><p class="text-grey-black dark:text-white text-[14px] text-center"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">Pro použití SimpleX přes Tor prosím nainstalujte </a><a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot aplikaci</a> a povolte SOCKS5 proxy (nebo VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">na iOS</a>).</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Pro použití SimpleX přes Tor prosím nainstalujte <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot aplikaci</a> a povolte SOCKS5 proxy (nebo VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">na iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1463,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Snižuje vektory útoku ve srovnání s tradičními zprostředkovateli zpráv a dostupnými metadaty.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1481,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Díky tomu vypadají zprávy různých velikostí pro servery a síťové pozorovatele stejně.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
                     </div>
                 </div>
                 
@@ -1963,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-</div><div id="tooltip-address-portability" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Address portability</h4><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div></div><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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+<link rel="describedby" href="/llms.txt"/>
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Máte naprosté soukromí</h3>
                             </div>
 
@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jste chráněni<br>před spamem a zneužitím</h3>
                             </div>
 
@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vy kontrolujete vaše data</h3>
                             </div>
 
@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vlastníte síť SimpleX</h3>
                             </div>
 
@@ -1452,7 +1456,7 @@ window.addEventListener('click',(e)=>{
     SimpleX síť používá <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">otevřený protokol</a> a poskytuje <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK k vytváření chat botů</a>, což umožní implementaci služeb, díky nimž boudou moci uživatelé komunikovat prostřednictvím aplikací SimpleX Chat — Opravdu se těšíme, jaké služby SimpleX vytvoříte.
 </p>
 <p>
-    Pokud uvažujete o vývoji pro SimpleX síť, například chat bot pro uživatele aplikace SimpleX nebo integraci knihovny SimpleX chat do Vasí mobilní aplikace, prosím <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
+    Pokud uvažujete o vývoji pro SimpleX síť, například chat bot pro uživatele aplikace SimpleX nebo integraci knihovny SimpleX chat do Vasí mobilní aplikace, prosím <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">buďte ve spojení</a> pro jakoukoli radu a podporu.
 </p>
 
                         </div>
@@ -1460,68 +1464,20 @@ window.addEventListener('click',(e)=>{
                 
 
                 
-                    <div class=" max-w-[448px]"="">
-                        </a></p><div class="flex items-center justify-center"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                    <div class="max-w-[448px]">
+                        <div class="flex items-center justify-center">
                             <img class="w-full max-w-[448px] min-w-[300px] dark:hidden" src="/img/new/unique-section-4.png" alt="">
                             <img class="w-full max-w-[448px] min-w-[300px] hidden dark:block" src="/img/new/unique-section-4-dark.png" alt="">
-                        </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
                         </div>
                     </div>
                 
-
-                
-                    <div class=" max-w-[448px]"="">
-                    </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-                
-            </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+            </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
                 <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
             </svg>
-        </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-    </a></div><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+        </div>
+    </div>
 
     
 
@@ -1616,44 +1572,12 @@ window.addEventListener('click',(e)=>{
 </section>
 
 
-</a><section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-    </a><div class="container scale-100"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+<section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
+    <div class="container scale-100">
         <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Co dělá SimpleX <span class="gradient-text">soukromým</span></h2>
 
-        </a><div class="swiper private-swiper overflow-hidden px-4 py-2"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
-            </a><div class="swiper-wrapper mb-16"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+        <div class="swiper private-swiper overflow-hidden px-4 py-2">
+            <div class="swiper-wrapper mb-16">
 
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
@@ -1780,50 +1704,18 @@ window.addEventListener('click',(e)=>{
                     </div>
                 </div>
                 
-                </a><div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
                         <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
                         <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
                     </div>
-                    </a><div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                    <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Volitelný<br>přístup přes Tor</h3>
-                        </a><div class="flex-1 py-3 flex flex-col gap-3"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">
+                        <div class="flex-1 py-3 flex flex-col gap-3">
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pro ochranu vaší IP adresy můžete přistupovat k serverům přes Tor nebo jinou transportní překryvnou síť.</p>
                             
-                            </a><p class="text-grey-black dark:text-white text-[14px] text-center"><a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank>buďte ve spojení</a> pro jakoukoli radu a podporu.
-</p>
-
-                        </div>
-                    </div>
-                
-
-                
-                    <div class=" max-w-[448px]"="">Pro použití SimpleX přes Tor prosím nainstalujte </a><a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot aplikaci</a> a povolte SOCKS5 proxy (nebo VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">na iOS</a>).</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Pro použití SimpleX přes Tor prosím nainstalujte <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot aplikaci</a> a povolte SOCKS5 proxy (nebo VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">na iOS</a>).</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">Klepnutím zavřete</p>
@@ -2271,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-</div><div id="tooltip-address-portability" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Address portability</h4><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div></div><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/cs/why.md b/cs/why.md
new file mode 100644
index 0000000000..dea45334ab
--- /dev/null
+++ b/cs/why.md
@@ -0,0 +1,19 @@
+# Narodili jste se bez účtu.
+
+Nikdo nesledoval vaše konverzace. Nikdo nevytvořil mapu, kde jste byli. Soukromí nikdy nebylo funkcí — byl to způsob života.
+
+Pak jsme se přesunuli na internet a každá platforma chtěla o vás něco vědět — vaše jméno, vaše číslo, vaše přátele. Smířili jsme se s tím, že cenou za komunikaci s ostatními je dát někomu vědět, s kým mluvíme. Každá generace, lidská i technická, to tak měla — telefon, e-mail, komunikátory, sociální sítě. Zdálo se, že je to jediný možný způsob.
+
+Existuje i jiný způsob. Síť bez telefonních čísel. Bez uživatelských jmen. Bez účtů. Bez jakékoli uživatelské identity. Síť, která spojuje lidi a přenáší šifrované zprávy, aniž by bylo známo, kdo je připojen.
+
+Nejde o to mít lepší zámek na dveřích někoho jiného. Ani o to mít nájemce, který respektuje vaše soukromí, ale vede evidenci všech vašich návštěvníků. Nejste host. Jste doma. Ani král k vám nemůže vstoupit — jste suverén.
+
+Vaše konverzace patří vám, jako tomu bylo vždy před internetem. Síť není místo, které navštěvujete. Je to místo, které vytváříte a vlastníte. A nikdo vám ho nemůže vzít, ať už je soukromé, nebo veřejné.
+
+Nejstarší lidská svoboda — mluvit s druhým člověkem, aniž by byl sledován — postavena na infrastruktuře, která ji nemůže zradit.
+
+Protože jsme zničili sílu vědět, kdo jste. Aby vám *vaši* moc nikdo nemohl vzít.
+
+Buďte svobodní ve své síti.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/cs/why/index.html b/cs/why/index.html
index 94c0e395be..a14fa2d529 100644
--- a/cs/why/index.html
+++ b/cs/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/cs/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Buďte svobodní ve své síti.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/css/tailwind.css b/css/tailwind.css
index 09a0b8530d..d98681ae11 100644
--- a/css/tailwind.css
+++ b/css/tailwind.css
@@ -2486,6 +2486,10 @@ video {
     margin-bottom: 2rem;
   }
 
+  .md\:mt-14 {
+    margin-top: 3.5rem;
+  }
+
   .md\:mt-6 {
     margin-top: 1.5rem;
   }
diff --git a/de/contact.md b/de/contact.md
new file mode 100644
index 0000000000..691ee0620c
--- /dev/null
+++ b/de/contact.md
@@ -0,0 +1,66 @@
+# Sie haben eine Adresse zur Verbindung mit SimpleX Chat erhalten
+
+## Scannen Sie den QR-Code mit der SimpleX Chat-App auf Ihrem Mobilgerät oder Tablet.
+
+Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen — sie sind in dem Hash-Fragment der Link-URL enthalten.
+
+SimpleX Chat noch nicht heruntergeladen?
+
+Nutzen Sie die unten genannten Links, um die Applikation herunterzuladen.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scannen Sie den QR-Code aus der mobilen Applikation
+
+# Sie haben eine Adresse zur Verbindung mit SimpleX Chat erhalten
+
+Um eine Verbindung zu starten:
+
+Installieren Sie die SimpleX-App
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid)
+
+1
+
+Verbinden Sie sich in der Applikation
+
+Öffnen Sie die SimpleX-App
+
+2
+
+Drücken Sie die „Verbinden“-Taste in der Applikation
+
+3
+
+## Scannen Sie den QR-Code mit der SimpleX Chat-App
+
+Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen —
+sie sind in dem Hash-Fragment der Link-URL enthalten.
+
+## Installation von SimpleX-Chat im Terminal
+
+Benutzen Sie dieses Kommando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Siehe SimpleX-Chat GitHub-Repository Für die Anleitungen, wie Sie es herunterladen oder aus dem Quellcode kompilieren.
+
+---
+
+## Wenn Sie den SimpleX-Chat schon für das Terminal installiert haben
+
+Wenn Sie es schon installiert haben SimpleX-Chat für das Terminal v1.0.0+, Kopieren Sie sich das unten genannte Kommando und nutzen Sie es im Chat:
+
+## Nutzen Sie SimpleX
+
+Wir laden Sie ein, sich an der Diskussion zu beteiligen
+
+[Treten Sie der Reddit-Gruppe bei](https://www.reddit.com/r/SimpleXChat/) [Schließen Sie sich uns bei GitHub an](https://github.com/simplex-chat) [Spenden Sie, um uns zu unterstützen](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Melden Sie sich an, um Updates von uns zu erhalten
+
+---
+
+Laden Sie sich SimpleX herunter [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid)
diff --git a/de/contact/index.html b/de/contact/index.html
index b5a2033c1f..3be6e3ca16 100644
--- a/de/contact/index.html
+++ b/de/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Sie haben eine Adresse zur Verbindung mit SimpleX Chat erhalten</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scannen Sie den QR-Code mit der SimpleX Chat-App auf Ihrem Mobilgerät oder Tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen — sie sind in dem Hash-Fragment der Link-URL enthalten.
+                Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen &mdash; sie sind in dem Hash-Fragment der Link-URL enthalten.
             </p>
             <p class="text-grey-black dark:text-white text-base">SimpleX Chat noch nicht heruntergeladen?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Nutzen Sie die unten genannten Links, um die Applikation herunterzuladen.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installieren Sie die SimpleX-App</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scannen Sie den QR-Code mit der SimpleX Chat-App</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen —<br> sie sind in dem Hash-Fragment der Link-URL enthalten.
+                            Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen &mdash;<br> sie sind in dem Hash-Fragment der Link-URL enthalten.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installation von SimpleX-Chat im Terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-Repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Wenn Sie den SimpleX-Chat schon für das Terminal installiert haben</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Melden Sie sich an, um Updates von uns zu erhalten</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Geben Sie Ihre Mail-Adresse ein">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Laden Sie sich SimpleX herunter <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/fdroid.md b/de/fdroid.md
new file mode 100644
index 0000000000..76728cdeb6
--- /dev/null
+++ b/de/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX-Chat per F-Droid
+
+### SimpleX Chat-Repository
+
+Von den Entwicklern erstellte stabile und Beta-Versionen
+
+Um es Ihrem F-Droid-Client hinzuzufügen, scannen Sie den QR-Code oder nutzen Sie diese URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Fingerabdruck des Signaturschlüssels (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org-Repository
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Von F-Droid.org erstellte stabile Versionen
+
+Die Versionen für dieses Repository werden einige Tage später erstellt.
+
+SimpleX Chat- und F-Droid.org-Repositorys signieren ihre Builds mit verschiedenen Schlüsseln. Zum Umschalten bitte [die Chat-Datenbank exportieren](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) und die App neu installieren.
diff --git a/de/fdroid/index.html b/de/fdroid/index.html
index ea4ccb0a5a..ccbb088c2f 100644
--- a/de/fdroid/index.html
+++ b/de/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX-Chat per F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Von den Entwicklern erstellte stabile und Beta-Versionen</p>
                         <p>Um es Ihrem F-Droid-Client hinzuzufügen, <span class="hide-on-mobile">scannen Sie den QR-Code oder</span> nutzen Sie diese URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Fingerabdruck des Signaturschlüssels (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org-Repository</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Von F-Droid.org erstellte stabile Versionen</p>
                 <p class="mb-2">Die Versionen für dieses Repository werden einige Tage später erstellt.</p>
                 <p class="mb-2">SimpleX Chat- und F-Droid.org-Repositorys signieren ihre Builds mit verschiedenen Schlüsseln. Zum Umschalten bitte <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">die Chat-Datenbank exportieren</a> und die App neu installieren.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/file.md b/de/file.md
new file mode 100644
index 0000000000..cbe6523a12
--- /dev/null
+++ b/de/file.md
@@ -0,0 +1,31 @@
+# SimpleX Dateiübertragung
+
+Datei per Drag & Drop hinzufügen
+
+oder
+
+Datei auswählen
+
+Max. 100 MB — die [SimpleX Chat App](https://simplex.chat/downloads) unterstützt Dateien bis zu 1 GB
+
+Versenden Sie Dateien via Ende-zu-Ende-Verschlüsselung — ohne Benutzerkonten und ohne Tracking.
+
+## Laden Sie sich die SimpleX Chat App herunter — die sicherste & private Messenger-App
+
+Die Dateiübertragung, die Sie gerade verwendet haben, nutzt dasselbe Datenweiterleitungsprotokoll wie SimpleX Chat. Die App bietet Ende‑zu‑Ende‑verschlüsselte Nachrichten, Sprach‑ und Videoanrufe, Gruppen sowie das Senden von Dateien. Kein Benutzerkonto. Keine Telefonnummer. Keine E‑Mail. Keine Benutzerprofil‑IDs.
+
+# XFTP-Protokoll: Der sicherste Dateitransfer
+
+### Es wird kein Benutzerkonto benötigt
+
+Jedes Dateifragment verwendet einen neuen zufälligen Schlüssel. Datenrouter kennen keine "Benutzer" oder "Dateien" — sie übertragen nur verschlüsselte Dateifragmente fester Größe.
+
+### Dreifach direkt in Ihrem Browser verschlüsselt
+
+Der für die Dateiverschlüsselung genutzte Schlüssel befindet sich ausschließlich im Hash‑Fragment der URL — Ihr Browser sendet ihn niemals an einen Server. Es gibt drei Verschlüsselungsebenen: TLS‑Transport, empfängerbezogene Verschlüsselung (ein eindeutiger, flüchtiger Schlüssel pro Transfer) und Ende‑zu‑Ende‑Verschlüsselung der Datei.
+
+### Unabhängig voneinander arbeitende Datenrouter
+
+Wenn die Datei in Fragmente aufgeteilt wurde, wird sie über Netzwerkrouter übertragen, die von unabhängigen Parteien betrieben werden. Kein Betreiber kann die tatsächliche Dateigröße oder den Dateinamen sehen. Selbst wenn ein Router kompromittiert wird, sieht er nur verschlüsselte Fragmente fester Größe. Die Fragmente werden von den Netzwerkroutern für etwa 48 Stunden zwischengespeichert.
+
+[Lesen Sie sich die XFTP‑Protokollspezifikation durch →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/de/file/index.html b/de/file/index.html
index 673359720b..6c14d23771 100644
--- a/de/file/index.html
+++ b/de/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,13 +665,13 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">SimpleX Dateiübertragung</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
-          <p>Datei per Drag &amp; Drop hinzufügen</p>
+          <p>Datei per Drag & Drop hinzufügen</p>
           <p class="hint">oder</p>
           <span class="btn">Datei auswählen</span>
-          <p class="hint">Max. 100 MB — die <a href="/downloads">SimpleX Chat App</a> unterstützt Dateien bis zu 1 GB</p>
+          <p class="hint">Max. 100 MB &mdash; die <a href="/downloads">SimpleX Chat App</a> unterstützt Dateien bis zu 1 GB</p>
         </div>
       </div>
     </div>
@@ -675,7 +682,7 @@ window.addEventListener('click',(e)=>{
           <p>File available</p>
           <button class="btn">Herunterladen</button>
           <div class="security-note">
-            <p>Diese Datei ist verschlüsselt — Datenrouter sehen weder Inhalt, Namen noch Größe der Datei.</p>
+            <p>Diese Datei ist verschlüsselt &mdash; Datenrouter sehen weder Inhalt, Namen noch Größe der Datei.</p>
             <p>Der für die Verschlüsselung genutzte Schlüssel befindet sich im Hash‑Fragment des Links und wird niemals an einen Server übertragen.</p>
             <p>Für noch mehr Sicherheit verwenden Sie die <a href="https://simplex.chat/downloads">SimpleX Chat App</a>.</p>
           </div>
@@ -685,7 +692,7 @@ window.addEventListener('click',(e)=>{
     <script>if(location.hash.length>50){var a=document.getElementById("app"),t=document.getElementById("dl-placeholder");if(a&&t)a.replaceChildren(t.content.cloneNode(true))}</script>
     <script type="module" src="/file-assets/index.js"></script>
 
-    <p class="text-base text-center text-grey-black dark:text-white mt-10 max-w-[600px]">Versenden Sie Dateien via Ende-zu-Ende-Verschlüsselung — ohne Benutzerkonten und ohne Tracking.</p>
+    <p class="text-base text-center text-grey-black dark:text-white mt-10 max-w-[600px]">Versenden Sie Dateien via Ende-zu-Ende-Verschlüsselung &mdash; ohne Benutzerkonten und ohne Tracking.</p>
     <a href="javascript:void(0)" data-show-overlay="xftp-protocol" class="open-overlay-btn file-proto-link mt-3 block text-center">Erfahren Sie mehr über das XFTP-Protokoll</a>
   </div>
 </section>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Laden Sie sich die SimpleX Chat App herunter — die sicherste &amp; private Messenger-App
+      Laden Sie sich die SimpleX Chat App herunter &mdash; die sicherste &amp; private Messenger-App
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       Die Dateiübertragung, die Sie gerade verwendet haben, nutzt dasselbe Datenweiterleitungsprotokoll wie SimpleX Chat. Die App bietet Ende‑zu‑Ende‑verschlüsselte Nachrichten, Sprach‑ und Videoanrufe, Gruppen sowie das Senden von Dateien. Kein Benutzerkonto. Keine Telefonnummer. Keine E‑Mail. Keine Benutzerprofil‑IDs.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/de/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/de/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -720,11 +727,11 @@ window.addEventListener('click',(e)=>{
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <div>
   <h3 class="font-bold text-lg mb-2">Es wird kein Benutzerkonto benötigt</h3>
-  <p>Jedes Dateifragment verwendet einen neuen zufälligen Schlüssel. Datenrouter kennen keine "Benutzer" oder "Dateien" — sie übertragen nur verschlüsselte Dateifragmente fester Größe.</p>
+  <p>Jedes Dateifragment verwendet einen neuen zufälligen Schlüssel. Datenrouter kennen keine "Benutzer" oder "Dateien" &mdash; sie übertragen nur verschlüsselte Dateifragmente fester Größe.</p>
 </div>
 <div>
   <h3 class="font-bold text-lg mb-2">Dreifach direkt in Ihrem Browser verschlüsselt</h3>
-  <p>Der für die Dateiverschlüsselung genutzte Schlüssel befindet sich ausschließlich im Hash‑Fragment der URL — Ihr Browser sendet ihn niemals an einen Server. Es gibt drei Verschlüsselungsebenen: TLS‑Transport, empfängerbezogene Verschlüsselung (ein eindeutiger, flüchtiger Schlüssel pro Transfer) und Ende‑zu‑Ende‑Verschlüsselung der Datei.</p>
+  <p>Der für die Dateiverschlüsselung genutzte Schlüssel befindet sich ausschließlich im Hash‑Fragment der URL &mdash; Ihr Browser sendet ihn niemals an einen Server. Es gibt drei Verschlüsselungsebenen: TLS‑Transport, empfängerbezogene Verschlüsselung (ein eindeutiger, flüchtiger Schlüssel pro Transfer) und Ende‑zu‑Ende‑Verschlüsselung der Datei.</p>
 </div>
 <div>
   <h3 class="font-bold text-lg mb-2">Unabhängig voneinander arbeitende Datenrouter</h3>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/index.html b/de/index.html
index 3a5a87dbfc..69c53b2e06 100644
--- a/de/index.html
+++ b/de/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/de/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/de/fdroid" title="SimpleX-App über das F-Droid-Repository"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Öffentlicher iOS-Preview auf TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Öffentlicher iOS-Preview auf TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security-Gutachten" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Jetzt</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Juni 2027</span>
diff --git a/de/index.md b/de/index.md
new file mode 100644
index 0000000000..62da4757eb
--- /dev/null
+++ b/de/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Sei frei
+
+## In Deinem Netzwerk
+
+Das erste Netzwerk ohne Benutzer-IDs.
+Ihre Kontakte, Gruppen und Kanäle gehören Ihnen.
+
+Investieren Sie in SimpleX Chat. [Erfahren Sie mehr darüber.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX-App über das F-Droid-Repository](https://simplex.chat/de/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security-Gutachten](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security-
+Audits
+
+[Messenger-Empfehlungen von Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix - Empfehlungen für Messenger](https://www.whonix.org/wiki/Chat#Recommendation) [Veröffentlichungen von Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Überprüfung von Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Podcast-Interview von OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Niemand kann sehen, mit wem Sie kommunizieren
+
+Alle Nachrichten sehen aus wie zufälliges Rauschen - auch für die Server.
+
+Täglich werden Dutzende Millionen Nachrichten privat zugestellt.
+
+[Lernen Sie mehr über SimpleX-Messaging](https://simplex.chat/de/messaging)
+
+## Das Netzwerk gehört Ihnen
+
+Jeder Kontakt und jede Gruppe wird auf Ihrem Gerät gespeichert, nicht in einer Server-Datenbank.
+
+Keine einzelne Instanz kontrolliert das Netzwerk – jeder kann Server betreiben.
+
+[Warum wir es erschaffen haben](https://simplex.chat/de/why)
+
+## Finanziert von seinen Nutzern
+
+Um unabhängig zu bleiben, werden große Kanäle und Communitys für ihre Server bezahlen.
+
+Und die Nutzer können jetzt in SimpleX Chat investieren — das Crowdfunding ist gestartet!
+
+[In SimpleX Chat investieren](https://simplex.chat/crowdfunding/)
+
+## SimpleX - Der Weg zum freien Internet
+
+2026
+
+: Skalierung auf große Communitys
+
+Ausstieg aus zentralisierten Plattformen
+
+Juni 2027
+
+: Nachhaltige Communitys & Server
+
+Einführung von Community-Credits
+
+Dez 2027
+
+: Lassen Sie Ihre Communitys wachsen
+
+Tools zur Förderung Ihrer Communitys
+
+[SimpleX-Nutzergruppe](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Treten Sie SimpleX-Communitys bei
+
+Mehr als 2 Millionen Nutzer haben schon SimpleX-Apps heruntergeladen.
+
+Finden Sie Kanäle und Communitys im Verzeichnis oder erstellen Sie Ihre Eigenen!
+
+[SimpleX-Verzeichnis anzeigen](https://simplex.chat/directory)
diff --git a/de/invitation.md b/de/invitation.md
new file mode 100644
index 0000000000..17542951cf
--- /dev/null
+++ b/de/invitation.md
@@ -0,0 +1,66 @@
+# Sie haben einen Einmal-Link zur Verbindung mit SimpleX Chat erhalten
+
+## Scannen Sie den QR-Code mit der SimpleX Chat-App auf Ihrem Mobilgerät oder Tablet.
+
+Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen — sie sind in dem Hash-Fragment der Link-URL enthalten.
+
+SimpleX Chat noch nicht heruntergeladen?
+
+Nutzen Sie die unten genannten Links, um die Applikation herunterzuladen.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scannen Sie den QR-Code aus der mobilen Applikation
+
+# Sie haben einen Einmal-Link zur Verbindung mit SimpleX Chat erhalten
+
+Um eine Verbindung zu starten:
+
+Installieren Sie die SimpleX-App
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid)
+
+1
+
+Verbinden Sie sich in der Applikation
+
+Öffnen Sie die SimpleX-App
+
+2
+
+Drücken Sie die „Verbinden“-Taste in der Applikation
+
+3
+
+## Scannen Sie den QR-Code mit der SimpleX Chat-App
+
+Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen —
+sie sind in dem Hash-Fragment der Link-URL enthalten.
+
+## Installation von SimpleX-Chat im Terminal
+
+Benutzen Sie dieses Kommando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Siehe SimpleX-Chat GitHub-Repository Für die Anleitungen, wie Sie es herunterladen oder aus dem Quellcode kompilieren.
+
+---
+
+## Wenn Sie den SimpleX-Chat schon für das Terminal installiert haben
+
+Wenn Sie es schon installiert haben SimpleX-Chat für das Terminal v1.0.0+, Kopieren Sie sich das unten genannte Kommando und nutzen Sie es im Chat:
+
+## Nutzen Sie SimpleX
+
+Wir laden Sie ein, sich an der Diskussion zu beteiligen
+
+[Treten Sie der Reddit-Gruppe bei](https://www.reddit.com/r/SimpleXChat/) [Schließen Sie sich uns bei GitHub an](https://github.com/simplex-chat) [Spenden Sie, um uns zu unterstützen](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Melden Sie sich an, um Updates von uns zu erhalten
+
+---
+
+Laden Sie sich SimpleX herunter [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/de/fdroid)
diff --git a/de/invitation/index.html b/de/invitation/index.html
index 9f2f016c80..75b5e7e25d 100644
--- a/de/invitation/index.html
+++ b/de/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Sie haben einen Einmal-Link zur Verbindung mit SimpleX Chat erhalten</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scannen Sie den QR-Code mit der SimpleX Chat-App auf Ihrem Mobilgerät oder Tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen — sie sind in dem Hash-Fragment der Link-URL enthalten.
+                Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen &mdash; sie sind in dem Hash-Fragment der Link-URL enthalten.
             </p>
             <p class="text-grey-black dark:text-white text-base">SimpleX Chat noch nicht heruntergeladen?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Nutzen Sie die unten genannten Links, um die Applikation herunterzuladen.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installieren Sie die SimpleX-App</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scannen Sie den QR-Code mit der SimpleX Chat-App</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen —<br> sie sind in dem Hash-Fragment der Link-URL enthalten.
+                            Die öffentlichen Schlüssel und die Adresse der Nachrichtenwarteschlange in diesem Link werden NICHT über das Netzwerk gesendet, wenn Sie diese Seite aufrufen &mdash;<br> sie sind in dem Hash-Fragment der Link-URL enthalten.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installation von SimpleX-Chat im Terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-Repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Wenn Sie den SimpleX-Chat schon für das Terminal installiert haben</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Melden Sie sich an, um Updates von uns zu erhalten</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Geben Sie Ihre Mail-Adresse ein">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Laden Sie sich SimpleX herunter <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/de/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/de/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/messaging.md b/de/messaging.md
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--- /dev/null
+++ b/de/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Warum ist SimpleX einmalig
+
+### Sie erhalten eine vollumfängliche Privatsphäre
+
+SimpleX schützt die Privatsphäre Ihres Profils, Ihrer Kontakte und Metadaten und verbirgt sie vor den SimpleX Netzwerk-Servern und weiteren möglichen Beobachtern.
+
+Im Gegensatz zu allen anderen bestehenden Messaging-Netzwerken werden den Nutzern von SimpleX keine Kennungen zugewiesen — **nicht einmal Zufallszahlen**.
+
+### Sie sind geschützt vor Spam und Missbrauch
+
+Da Sie keine Kennung oder feste Adresse im SimpleX-Netzwerk haben, kann Sie niemand kontaktieren, es sei denn, Sie geben eine einmalige oder vorübergehende Benutzeradresse in Form eines QR-Codes oder Links weiter.
+
+### Sie haben die Kontrolle über Ihre Daten
+
+SimpleX speichert Benutzerdaten nur auf den Endgeräten und das in einem **portablen, verschlüsselten Datenbankformat** — welches auf ein anderes Gerät übertragen werden kann.
+
+Ende-zu-Ende verschlüsselte Nachrichten werden vorübergehend auf SimpleX Relay-Servern gespeichert, bis sie vom Endgerät empfangen und danach endgültig gelöscht werden.
+
+### Sie besitzen das SimpleX-Netzwerk
+
+Das SimpleX-Netzwerk ist vollständig dezentralisiert und unabhängig von Kryptowährungen oder anderen Netzwerken außer dem Internet.
+
+Sie können **SimpleX mit eigenen Servern** oder mit den von uns zur Verfügung gestellten Servern verwenden — und sich trotzdem mit jedem Benutzer verbinden.
+
+# Komplette Privatsphäre für Ihre Identität, ihr Profil, Ihre Kontakte und Metadaten
+
+Im Gegensatz zu anderen Nachrichten-Netzwerken weist SimpleX **den Benutzern keine Kennungen** zu. Es verlässt sich nicht auf Telefonnummern, domänenbasierte Adressen (wie E-Mail oder XMPP), Benutzernamen, öffentliche Schlüssel oder Zufallszahlen, um seine Benutzer zu identifizieren — selbst SimpleX Server-Betreiber wissen nicht, wie viele Personen deren Server verwenden.
+
+Um Nachrichten auszuliefern nutzt SimpleX [paarweise anonyme Adressen](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) aus unidirektionalen Nachrichten-Warteschlangen, die für empfangene und gesendete Nachrichten separiert sind und gewöhnlich über verschiedene Server gesendet werden.
+
+Dieses Design schützt die Privatsphäre von Ihnen und der Nutzer, mit denen Sie kommunizieren, und verbirgt die Verbindungen vor den SimpleX Netzwerk-Servern und möglichen Beobachtern. Um Ihre IP-Adresse vor den Servern zu verbergen, können Sie sich **per Tor mit den SimpleX-Servern verbinden**.
+
+# Der beste Schutz vor Spam und Missbrauch
+
+Da Sie im SimpleX-Netzwerk keine Kennungen haben, kann Sie niemand kontaktieren, es sei denn, Sie geben eine einmalige oder vorübergehende Benutzeradresse in Form eines QR-Codes oder eines Links weiter.
+
+Auch wenn die optionale Benutzeradresse zum Versenden von Spam-Kontaktanfragen verwendet werden kann, können Sie sie ändern oder ganz löschen, ohne dass Ihre Verbindungen verloren gehen.
+
+# Besitz, Kontrolle und Sicherheit Ihrer Daten
+
+SimpleX Chat speichert alle Benutzerdaten ausschließlich auf den Endgeräten in einem **portablen und verschlüsselten Datenbankformat**, welches exportiert und auf jedes unterstützte Gerät übertragen werden kann.
+
+Ende-zu-Ende verschlüsselte Nachrichten werden vorübergehend auf SimpleX Relay-Servern gespeichert, bis sie vom Endgerät empfangen und danach endgültig gelöscht werden.
+
+Im Gegensatz zu föderierten Netzwerkservern (wie z.B. Mail, XMPP oder Matrix) speichern die SimpleX-Server keine Benutzerkonten, sondern leiten Nachrichten nur weiter, so dass die Privatsphäre der beteiligten Parteien geschützt ist.
+
+Zwischen dem gesendeten und dem empfangenen Serververkehr gibt es keine gemeinsamen Kennungen oder Chiffriertexte — sodass ein Beobachter nicht ohne weiteres feststellen kann, wer mit wem kommuniziert, selbst wenn TLS kompromittiert wurde.
+
+# Voll dezentralisiert — Die Nutzer besitzen das SimpleX-Netzwerk
+
+Sie können **SimpleX mit eigenen Servern verwenden** und trotzdem mit Nutzern kommunizieren, welche die vorkonfigurierten Server der App verwenden.
+
+Das SimpleX-Netzwerk verwendet ein [offenes Protokoll](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) und bietet ein [SDK zur Erstellung von Chatbots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript) an. Dies ermöglicht die Erstellung von Diensten, mit denen Nutzer über SimpleX Chat-Apps interagieren können — wir freuen uns sehr darauf zu sehen, welche SimpleX-Dienste Sie entwickeln werden.
+
+Falls Sie Interesse daran haben, aktiv bei der Entwicklung des SimpleX-Netzwerks mitzuhelfen, z.B. einen Chatbot für SimpleX App-Nutzer zu entwickeln oder die Integration der SimpleX Chat-Bibliothek in mobile Apps voranzutreiben, [kontaktieren Sie uns bitte](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) für eine weitere Beratung und Unterstützung.
+
+## Funktionen
+
+Ende-zu-Ende-verschlüsselte Nachrichten mit Markdowns und Bearbeitungsmöglichkeiten
+
+Ende-zu-Ende-verschlüsselte
+Bilder, Videos und Dateien
+
+Ende-zu-Ende-verschlüsselte dezentralisierte Gruppen — Nur die Nutzer wissen, dass diese überhaupt existieren
+
+Ende-zu-Ende-verschlüsselte Sprachnachrichten
+
+Verschwindende geheime Unterhaltungen
+
+Ende-zu-Ende-verschlüsselte Sprach- und Videoanrufe
+
+Portable und verschlüsselte App-Datenspeicherung — verschieben Sie das komplette Profil einfach auf ein anderes Gerät
+
+Inkognito-Modus —
+Einzigartig in SimpleX Chat
+
+## Was macht SimpleX vertraulich
+
+### Temporäre, anonyme paarweise Kennungen
+
+SimpleX nutzt für jeden Nutzer-Kontakt oder jedes Gruppenmitglied eigene temporäre, anonyme und paarweise Adressen und Berechtigungsnachweise.
+
+SimpleX ermöglicht die Zustellung von Nachrichten ohne Nutzerprofil-Kennungen und bietet dabei bessere Metadaten-Privatsphäre als andere Alternativen.
+
+### Out-of-Band- Schlüsselaustausch
+
+Viele Kommunikations-Netzwerke sind für MITM-Angriffe durch Server oder Netzwerk-Anbieter anfällig.
+
+Um das zu verhindern, werden von SimpleX Einmal-Schlüssel Out-of-Band weitergeleitet, wenn Sie eine Adresse als Link oder QR-Code teilen.
+
+### Zwei Schichten der Ende-zu-Ende-Verschlüsselung
+
+Double-Ratchet-Protokoll —
+Off-the-Record-Nachrichten mit Perfect Forward Secrecy, Abstreitbarkeit und Wiederherstellung nach einer Kompromittierung.
+
+NaCL-Kryptobox in jeder Warteschlange, um eine Korrelation des Datenverkehrs zwischen Nachrichtenwarteschlangen zu verhindern, falls TLS kompromittiert wurde.
+
+### Nachrichten-Integritäts- Überprüfung
+
+Um die Integrität von Nachrichten sicherzustellen, werden sie sequentiell durchnummeriert und beinhalten den Hash der vorhergehenden Nachricht.
+
+Der Empfänger wird alarmiert, sobald eine Nachricht ergänzt, entfernt oder verändert wird.
+
+### Zusätzliche Schicht der Server-Verschlüsselung
+
+Zusätzliche Server-Verschlüsselungs-Schicht für die Zustellung an den Empfänger, um eine Korrelation zwischen empfangenen und gesendeten Server-Daten zu vermeiden, falls TLS kompromittiert wurde.
+
+### Mischen von Nachrichten, um Korrelationen zu reduzieren
+
+Die SimpleX-Server arbeiten als Mix-Knoten mit geringer Verzögerung — eingehende und ausgehende Nachrichten haben eine unterschiedliche Reihenfolge.
+
+### Sichere authentifizierte TLS-Transportschicht
+
+Für Client-Server-Verbindungen wird nur TLS 1.2/1.3 mit starken Algorithmen verwendet.
+
+Server-Fingerabdrücke und Kanalbindung verhindern MITM- und Replay-Angriffe.
+
+Die Wiederaufnahme von Verbindungen ist deaktiviert, um Sitzungs-Angriffe zu verhindern.
+
+### Optionaler Zugang per Tor
+
+Um Ihre IP-Adresse zu schützen, können Sie per Tor oder irgendeinem anderen Transportschichten-Netzwerk auf Server zugreifen.
+
+Um SimpleX per Tor zu nutzen, installieren Sie unter Android bitte die [Orbot-App](https://guardianproject.info/apps/org.torproject.android/) und aktivieren Sie den SOCKS5-Proxy oder [unter iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone) per VPN.
+
+### Unidirektionale Nachrichten-Warteschlangen
+
+Jede Nachrichten-Warteschlange leitet Nachrichten mit unterschiedlichen Sende- und Empfängeradressen jeweils nur in einer Richtung weiter.
+
+Verglichen mit traditionellen Nachrichten-Brokern, werden mögliche Angriffs-Vektoren und vorhandene Metadaten reduziert.
+
+### Mehrere Schichten der Inhalteauffüllung
+
+SimpleX nutzt Inhalteauffüllung für jede Verschlüsselungs-Schicht, um Angriffe auf die Nachrichtengröße zu vereiteln.
+
+Erzeugt Nachrichten mit unterschiedlichen Größen, die für Server und Netzwerk-Beobachter identisch aussehen.
+
+## SimpleX-Netzwerk
+
+Durch die Kombination der Vorteile von P2P und föderierten Netzwerken stellt SimpleX Chat die bestmögliche Privatsphäre zur Verfügung.
+
+### Im Gegensatz zu P2P-Netzwerken
+
+Alle Nachrichten werden über Server versandt, was sowohl einen besseren Schutz der Metadaten als auch eine zuverlässigere asynchrone Nachrichtenübermittlung ermöglicht und dabei Vieles vermeidet .
+
+# Vergleich mit P2P-Nachrichten-Protokollen
+
+[Peer-to-Peer](https://en.wikipedia.org/wiki/Peer-to-peer)-Nachrichten-Protokolle und -Applikationen haben verschiedene Probleme, die diese weniger vertrauenswürdig, die Analyse wesentlich komplexer und anfälliger gegen verschiedene Arten von Angriffen, als bei SimpleX machen.
+
+1. P2P-Netzwerke vertrauen auf Varianten von [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table), um Nachrichten zu routen. DHT-Designs müssen zwischen Zustellungsgarantie und Latenz ausgleichen. Verglichen mit P2P bietet SimpleX sowohl eine bessere Zustellungsgarantie als auch eine niedrigere Latenz, weil eine Nachricht redundant und parallel über mehrere Server gesendet werden kann, wobei die durch den Empfänger ausgewählten Server genutzt werden. In P2P-Netzwerken werden Nachrichten sequentiell über *O(log N)*-Knoten gesendet, wobei die Knoten durch einen Algorithmus ausgewählt werden.
+2. Das SimpleX-Design hat, im Gegensatz zu den meisten P2P-Netzwerken, keinerlei globalen Benutzerkennungen, auch keine temporären. Es nutzt ausschließlich temporäre paarweise Kennungen, die bessere Anonymität und Metadaten-Schutz bieten.
+3. P2P löst nicht das Problem des [MITM-Angriffs](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) und die meisten bestehenden Implementierungen nutzen für den initialen Schlüsselaustausch keine Out-of-Band-Nachrichten. Im Gegensatz hierzu nutzt SimpleX für den initialen Schlüsselaustausch Out-of-Band-Nachrichten oder zum Teil schon bestehende sichere und vertrauenswürdige Verbindungen.
+4. ——P2P-Implementierungen können durch Internetanbieter blockiert werden, wie beispielweise [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX ist transportunabhängig — es kann über Standard-Web-Protokolle, wie beispielsweise WebSockets, arbeiten.
+5. Alle bekannten P2P-Netzwerke können anfällig für [Sybil-Angriffe](https://en.wikipedia.org/wiki/Sybil_attack) sein, da jeder Knoten ermittelbar ist und das Netzwerk als Ganzes funktioniert. Bekannte Maßnahmen zur Verhinderung erfordern entweder eine zentralisierte Komponente oder einen teuren [Ausführungsnachweis](https://en.wikipedia.org/wiki/Proof_of_work). Das SimpleX-Netzwerk bietet keine Ermittlung der Server, ist fragmentiert und arbeitet mit mehreren isolierten Subnetzwerken, wodurch netzwerkweite Angriffe unmöglich werden.
+6. P2P-Netzwerke können anfällig für [DRDoS-Angriffe](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) sein, wenn die Clients den Datenverkehr erneut senden und verstärken können, was zu einem netzwerkweiten Denial-of-Service führt. SimpleX-Clients leiten nur Datenverkehr von bekannten Verbindungen weiter und können von einem Angreifer nicht dazu verwendet werden, den Datenverkehr im gesamten Netzwerk zu verstärken.
+
+---
+
+### Im Gegensatz zu föderierten Netzwerken
+
+SimpleX Relay-Server speichern KEINE Benutzerprofile, Kontakte und zugestellte Nachrichten und stellen KEINE Verbindungen untereinander her, und es gibt KEIN Serververzeichnis.
+
+---
+
+### SimpleX-Netzwerk
+
+Die Server stellen unidirektionale Warteschlangen zur Verfügung, um die Benutzer miteinander zu verbinden. Sie haben aber keinen Einblick in den Verbindungs-Graphen des Netzwerks — Diesen haben nur die Benutzer selbst.
+
+## SimpleX erklärt
+
+1. Wie es die Nutzer erleben
+
+2. Wie es funktioniert
+
+3. Was die Server sehen
+
+1. Wie es die Nutzer erleben
+
+Sie können Kontakte und Gruppen erstellen und haben Zwei-Wege-Kommunikation wie in jedem anderen Messenger.
+
+Wie funktioniert das mit den unidirektionalen Warteschlangen und ohne Profilkennungen?
+
+2. Wie es funktioniert
+
+Für jede Verbindung nutzen Sie zwei separate Nachrichten-Warteschlangen, um die Nachrichten über verschiedene Server zu senden und zu empfangen.
+
+Die Server leiten Nachrichten immer nur in eine Richtung weiter, ohne den vollständigen Verlauf der Nutzer-Unterhaltungen oder seiner Verbindungen zu kennen.
+
+3. Was die Server sehen
+
+Die Server nutzen für jede Warteschlange separate, anonyme Anmeldeinformationen und wissen nicht, welchem Nutzer diese gehören.
+
+Durch die Verwendung von Tor-Zugangsservern können Nutzer ihre Metadaten-Privatsphäre weiter verbessern und Korrelationen von IP-Adressen verhindern.
+
+## Vergleich mit anderen Protokollen
+
+|  |  | Signal, große Plattformen | XMPP / Matrix | P2P-Protokolle |
+| --- | --- | --- | --- | --- |
+| Benötigt eine globale Kennung | Nein – vertraulich | Ja [1] | Ja [2] | Ja [3] |
+| Möglichkeit eines MITM-Angriffs | Nein – sicher [4] | Ja [5] | Ja | Ja |
+| Abhängigkeit vom DNS-System | Nein – widerstandsfähig | Ja | Ja | Nein |
+| Einzelnes oder zentralisiertes Netzwerk | Nein – dezentralisiert | Ja | Nein – föderiert [6] | Ja [7] |
+| Zentrale Komponente oder andere Netzwerk-weite Angriffe | Nein – widerstandsfähig | Ja | Ja [2] | Ja [8] |
+
+---
+
+1. Normalerweise auf der Grundlage einer Telefonnummer, in einigen Fällen auf der Grundlage von Benutzernamen
+2. DNS-basierte Adressen
+3. Öffentlicher Schlüssel oder eine andere weltweit eindeutige ID
+4. SimpleX-Relais können die E2E-Verschlüsselung nicht kompromittieren. Überprüfen Sie den Sicherheitscode, um einen möglichen Angriff auf den Out-of-Band-Kanal zu entschärfen
+5. Wenn die Server des Betreibers kompromittiert werden. In Signal und weiteren Apps kann der Sicherheitscode überprüft werden, um dies zu entschärfen
+6. Die Privatsphäre-Metadaten des Nutzers werden nicht geschützt
+7. P2P sind zwar verteilt, aber nicht föderiert — sie arbeiten als ein einziges Netzwerk
+8. P2P-Netzwerke haben entweder eine zentrale Verwaltung oder das gesamte Netzwerk kann kompromittiert werden — [Siehe hier](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Sicherheitsvergleich der Ende-zu-Ende-Verschlüsselung in verschiedenen Messengern
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Nachrichten-Inhalteauffüllung | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Glaubhafte Abstreitbarkeit | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward Secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Sicherheit nach Kompromittierung | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-Faktor-Schlüsselaustausch | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-Quanten-Hybridkryptografie | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar verwendet Inhalteauffüllung, um Nachrichten auf eine Länge von mindestens 1024 Byte aufzurunden; Signal - auf 160 Byte
+2. Abstreitbarkeit gilt nicht für die Client-Server-Verbindung.
+3. Es scheint, dass die Verwendung kryptografischer Signaturen die Abstreitbarkeit beeinträchtigt, aber dies muss noch geklärt werden.
+4. Die Multi-Geräte-Implementierung beeinträchtigt die Sicherheit nach Kompromittierung des Double Ratchet-Algorithmus — [Siehe hier](https://eprint.iacr.org/2021/626.pdf).
+5. Ein 2-Faktor-Schlüsselaustausch ist optional und kann über die Überprüfung eines Sicherheitscodes erfolgen.
+6. Die Schlüsselvereinbarung per Post-Quanten-Security ist nicht durchgängig — Sie schützt lediglich ausgewählte Schritte innerhalb des Ratchet-Prozesses.
diff --git a/de/messaging/index.html b/de/messaging/index.html
index 6bb8e7cb38..24971ec894 100644
--- a/de/messaging/index.html
+++ b/de/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie erhalten eine vollumfängliche Privatsphäre</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie sind geschützt vor<br>Spam und Missbrauch</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie haben die Kontrolle über Ihre Daten</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie besitzen das SimpleX-Netzwerk</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX ermöglicht die Zustellung von Nachrichten ohne Nutzerprofil-Kennungen und bietet dabei bessere Metadaten-Privatsphäre als andere Alternativen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Um das zu verhindern, werden von SimpleX Einmal-Schlüssel Out-of-Band weitergeleitet, wenn Sie eine Adresse als Link oder QR-Code teilen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL-Kryptobox in jeder Warteschlange, um eine Korrelation des Datenverkehrs zwischen Nachrichtenwarteschlangen zu verhindern, falls TLS kompromittiert wurde.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Der Empfänger wird alarmiert, sobald eine Nachricht ergänzt, entfernt oder verändert wird.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Zusätzliche Server-Verschlüsselungs-Schicht für die Zustellung an den Empfänger, um eine Korrelation zwischen empfangenen und gesendeten Server-Daten zu vermeiden, falls TLS kompromittiert wurde.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Die SimpleX-Server arbeiten als Mix-Knoten mit geringer Verzögerung — eingehende und ausgehende Nachrichten haben eine unterschiedliche Reihenfolge.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Die Wiederaufnahme von Verbindungen ist deaktiviert, um Sitzungs-Angriffe zu verhindern.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Um SimpleX per Tor zu nutzen, installieren Sie unter Android bitte die <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot-App</a> und aktivieren Sie den SOCKS5-Proxy oder <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">unter iOS</a> per VPN.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Verglichen mit traditionellen Nachrichten-Brokern, werden mögliche Angriffs-Vektoren und vorhandene Metadaten reduziert.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Erzeugt Nachrichten mit unterschiedlichen Größen, die für Server und Netzwerk-Beobachter identisch aussehen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Zum Schließen drücken</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/old/index.html b/de/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie erhalten eine vollumfängliche Privatsphäre</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie sind geschützt vor<br>Spam und Missbrauch</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie haben die Kontrolle über Ihre Daten</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sie besitzen das SimpleX-Netzwerk</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/de/why.md b/de/why.md
new file mode 100644
index 0000000000..e5f1caa282
--- /dev/null
+++ b/de/why.md
@@ -0,0 +1,19 @@
+# Sie wurden ohne ein Benutzerkonto geboren.
+
+Niemand verfolgte Ihre Gespräche. Niemand erstellte eine Karte, wo Sie sich aufgehalten haben. Privatsphäre war nie ein Feature — sie war selbstverständlich.
+
+Dann sind wir online gegangen, und jede Plattform wollte Etwas von Ihnen — Ihren Namen, Ihre Nummer, Ihre Freunde. Wir akzeptierten, dass es der Preis mit Anderen zu kommunizieren ist, Jemandem preiszugeben, mit wem und wie wir miteinander kommunizieren. Jede Generation, Menschen und Technologien, kannten es nur so — Telefon, E-Mail, Messenger, soziale Medien. Es schien der einzig mögliche Weg zu sein.
+
+Es gibt einen anderen Weg. Ein Netzwerk ohne Telefonnummern, ohne Benutzerkonten, ohne Benutzerkennungen und ohne jegliche Benutzeridentität. Ein Netzwerk, welches Menschen verbindet und verschlüsselte Nachrichten überträgt, ohne zu wissen, wer mit wem verbunden ist.
+
+Nicht ein besseres Schloss an der Tür eines Anderen. Kein freundlicher Vermieter, der Ihre Privatsphäre respektiert, aber dennoch jeden Besucher registriert. Sie sind kein Gast. Sie sind zu Hause. Kein Vermieter, kein Fremder kann es betreten — Sie sind souverän.
+
+Ihre Kommunikation gehört Ihnen, so wie es immer war, bevor es das Internet gab. Das Netzwerk ist kein Ort, den Sie besuchen. Es ist ein Ort, den Sie erschaffen und besitzen und Niemand kann es Ihnen nehmen, egal ob Sie es privat oder öffentlich machen.
+
+Die älteste Freiheit des Menschen — mit einem anderen Menschen sprechen zu können, ohne beobachtet zu werden — gestützt auf einer Infrastruktur, die Sie nicht verraten kann.
+
+Weil wir die Macht zerstört haben, zu wissen, wer Sie sind. Damit *Ihnen Ihre* Macht niemals genommen werden kann.
+
+Genießen Sie die Freiheit in Ihrem Netzwerk.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/de/why/index.html b/de/why/index.html
index cb21d66568..8e85a04efd 100644
--- a/de/why/index.html
+++ b/de/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/de/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Genießen Sie die Freiheit in Ihrem Netzwerk.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/directory.md b/directory.md
new file mode 100644
index 0000000000..8e098b8094
--- /dev/null
+++ b/directory.md
@@ -0,0 +1,9 @@
+# SimpleX Directory
+
+Welcome to the selected users' communities that you can join via [SimpleX Chat app](https://simplex.chat/downloads).
+
+SimpleX Directory is also available as a [SimpleX chat bot](https://smp4.simplex.im/a#lXUjJW5vHYQzoLYgmi8GbxkGP41_kjefFvBrdwg-0Ok).
+
+Read about [how to add](https://simplex.chat/docs/directory.html) your community.
+
+All listed groups and channels in JSON, with names, descriptions, member counts, join links and activity times: [directory.simplex.chat/data/listing.json](https://directory.simplex.chat/data/listing.json).
diff --git a/directory/index.html b/directory/index.html
index 3c332dcbaf..1dc65c1c42 100644
--- a/directory/index.html
+++ b/directory/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/directory.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+<script src="/js/flag-anchor.js"></script>
 
 
 <style>
@@ -732,13 +739,14 @@ window.addEventListener('click',(e)=>{
   }
 </style>
 
-</head><body><section class="py-10 px-5 mt-[66px] dark:text-white">
+<section class="py-10 px-5 mt-[66px] dark:text-white">
   <div class="container">
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">SimpleX Directory</h1>
     <p>Welcome to the selected users' communities that you can join via <a href="/downloads">SimpleX Chat
         app</a>.</p>
     <p>SimpleX Directory is also available as a <a href="https://smp4.simplex.im/a#lXUjJW5vHYQzoLYgmi8GbxkGP41_kjefFvBrdwg-0Ok" target="_blank">SimpleX chat bot</a>.</p>
     <p>Read about <a href="/docs/directory.html">how to add</a> your community.</p>
+    <template data-markdown><p>All listed groups and channels in JSON, with names, descriptions, member counts, join links and activity times: <a href="https://directory.simplex.chat/data/listing.json">directory.simplex.chat/data/listing.json</a>.</p></template>
     <div class="search-container">
       <input id="search" autocomplete="off">
       <div id="top-pagination" class="pagination">
@@ -753,17 +761,7 @@ window.addEventListener('click',(e)=>{
 </section>
 
 <script src="/js/directory.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/docs.md b/docs.md
new file mode 100644
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--- /dev/null
+++ b/docs.md
@@ -0,0 +1,46 @@
+# SimpleX documentation
+
+All documentation pages in Markdown. The same pages in HTML are at the same addresses with `.html` instead of `.md`.
+
+- [About us](https://simplex.chat/about.md)
+- [Accessing files in Android app](https://simplex.chat/docs/android.md)
+- [SimpleX for business](https://simplex.chat/docs/business.md)
+- [Hosting your own Chat Relay](https://simplex.chat/docs/chat-relay.md)
+- [Terminal CLI](https://simplex.chat/docs/cli.md)
+- [Code of Conduct](https://simplex.chat/docs/code_of_conduct.md)
+- [Contributing guide](https://simplex.chat/docs/contributing.md)
+- [SimpleX Directory](https://simplex.chat/docs/directory.md)
+- [Glossary](https://simplex.chat/docs/glossary.md)
+- [App settings](https://simplex.chat/docs/guide/app-settings.md)
+- [Audio & video Calls](https://simplex.chat/docs/guide/audio-video-calls.md)
+- [Channel webpage](https://simplex.chat/docs/guide/channel-webpage.md)
+- [Chat profiles](https://simplex.chat/docs/guide/chat-profiles.md)
+- [Making connections](https://simplex.chat/docs/guide/making-connections.md)
+- [Managing data](https://simplex.chat/docs/guide/managing-data.md)
+- [Privacy & security](https://simplex.chat/docs/guide/privacy-security.md)
+- [Quick start](https://simplex.chat/docs/guide/readme.md)
+- [Registering a SimpleX name](https://simplex.chat/docs/guide/register-simplex-name.md)
+- [Secret groups](https://simplex.chat/docs/guide/secret-groups.md)
+- [Sending messages](https://simplex.chat/docs/guide/send-messages.md)
+- [SimpleX Supporter Badges](https://simplex.chat/docs/protocol/badges-overview.md)
+- [Badge service RPC protocol](https://simplex.chat/docs/protocol/badges-rpc.md)
+- [SimpleX Channels: stateful information delivery and management](https://simplex.chat/docs/protocol/channels-overview.md)
+- [SimpleX Channels Protocol](https://simplex.chat/docs/protocol/channels-protocol.md)
+- [SimpleX Public Names for Channels and Businesses](https://simplex.chat/docs/protocol/names-overview.md)
+- [SimpleX Chat Protocol](https://simplex.chat/docs/protocol/simplex-chat.md)
+- [Hosting your own SMP Server](https://simplex.chat/docs/server.md)
+- [SimpleX platform](https://simplex.chat/docs/simplex.md)
+- [App color themes](https://simplex.chat/docs/themes.md)
+- [SimpleX Chat Trademark Policy](https://simplex.chat/docs/trademark.md)
+- [Contributing SimpleX app translations](https://simplex.chat/docs/translations.md)
+- [Using custom WebRTC ICE servers](https://simplex.chat/docs/webrtc.md)
+- [Why we are building SimpleX Network](https://simplex.chat/docs/why.md)
+- [Hosting your own XFTP Server](https://simplex.chat/docs/xftp-server.md)
+- [Please support us with donations](https://simplex.chat/donate.md)
+- [Download SimpleX apps](https://simplex.chat/downloads.md)
+- [Frequently Asked Questions](https://simplex.chat/faq.md)
+- [Join SimpleX Chat team](https://simplex.chat/jobs.md)
+- [Verify and reproduce builds](https://simplex.chat/reproduce.md)
+- [Security Policy](https://simplex.chat/security.md)
+- [Transparency Reports](https://simplex.chat/transparency.md)
+
diff --git a/docs/android.html b/docs/android.html
index 242972af32..e42ad286d4 100644
--- a/docs/android.html
+++ b/docs/android.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/android.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/android.md b/docs/android.md
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--- /dev/null
+++ b/docs/android.md
@@ -0,0 +1,52 @@
+| 07.02.2023 | EN, [CZ](https://simplex.chat/docs/lang/cs/android.html), [FR](https://simplex.chat/docs/lang/fr/android.html), [PL](https://simplex.chat/docs/lang/pl/android.html) |
+
+# Accessing files in Android app
+
+SimpleX uses databases and stores its preferences inside private data directory in Android. The directory contains:
+- databases
+- sent and received files
+- temporary files that will be deleted when not needed
+- user preferences.
+
+
+If you want to view what's stored inside SimpleX data directory you need to have:
+- Unix-based operating system (or [MinGW](https://www.mingw-w64.org/downloads/) on Windows)
+- ADB (Android Debug Bridge) tool installed on a computer ([download it here](https://developer.android.com/studio/releases/platform-tools) and install)
+- your device connected via USB or Wi-Fi to the computer.
+
+## The process:
+
+- open SimpleX, go to `Database passphrase & export`, enable `App data backup`. This will make other steps working
+- _optional_: if you want to view database contents, change database passphrase from random to yours. To do this, stop a chat in `Database passphrase & export` screen, open `Database passphrase`, enter new passphrase and confirm it, then update it. Do not forget it, otherwise you'll lose all your data in case passphrase will be asked again later
+- open a terminal emulator (Windows CMD/Powershell will not work) and change directory to the one you want to use for storing the backup:
+
+```bash
+cd /tmp  # just an example
+```
+Then run the following:
+```bash
+adb -d backup -f chat.ab -noapk chat.simplex.app && 
+tail -n +5 chat.ab > chat.dat && 
+printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" | cat - chat.dat > chat.gz && 
+tar -xvzf chat.gz
+```
+
+Now unlock the device and confirm a backup operation without using a password for encryption, otherwise the commands will not work.
+
+After that the backup should be ended. If you see an error saying `tar: Error is not recoverable: exiting now` but before that you have printed some file names, don't worry, it's ok.
+
+Now the backed-up files will be inside `./apps/chat.simplex.app/`.
+
+Please, note, that if you use a modern version of SimpleX, the databases will be encrypted, and you'll not be able to view contents of them without using `sqlcipher` application and without knowing decryption passphrase (you need to change it to yours from randomly generated in the app firstly).
+
+## Decrypting databases
+
+In order to view database data you need to decrypt it first. Install `sqlcipher` using your favorite package manager and run the following commands in the directory with databases:
+```bash
+sqlcipher files_chat.db
+pragma key="yourDecryptionPassphrase";
+# Ensure it works fine
+select * from users;
+```
+
+If you see `Parse error: no such table: users`, make sure you entered correct passphrase, and you have changed passphrase from random in Android app (if you got this database from Android device, of course).
diff --git a/docs/business.html b/docs/business.html
index 92f06e5bcd..eaf0f08ccc 100644
--- a/docs/business.html
+++ b/docs/business.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/business.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/business.md b/docs/business.md
new file mode 100644
index 0000000000..386b334adf
--- /dev/null
+++ b/docs/business.md
@@ -0,0 +1,122 @@
+# Using SimpleX Chat in business
+
+SimpleX Chat (aka SimpleX) is a decentralized communication network that provides private and secure messaging. Its users are rapidly growing, and providing customer services via SimpleX can offer you a unique opportunity to engage people who are the most enthusiastic about trying out early stage technology products and services.
+
+This document aims to help you make the best use of SimpleX Chat if you choose to engage with its users.
+
+## Communicate with customers via business address
+
+In the same way you can connect to our "SimpleX Chat team" profile via the app, you can provide the address for your existing and prospective customers:
+- to buy your product and services via chat,
+- to ask any questions, make suggestions and provide feedback,
+- to discover more information about your business.
+
+Customers who value privacy and security, and want to engage with you without sharing any personal data and minimizing any metadata that is shared with you, will be really happy to use this communication channel.
+
+From v6.2 SimpleX Chat supports business addresses. Their design allows you to accept requests from multiple customers, with the app creating a new business chat with each of them.
+
+Business chats operate in a way similar to dedicated customer support systems by combining features of direct conversations and groups, and the only widely used messenger that provides such functionality is WeChat with Chinese business accounts.
+
+When a customer connects to your business via the business contact address, a new conversation is created. Similarly to how direct chats work, the customer will see the name and logo of your business, and you will see the name and avatar of your customer.
+
+But the business conversation works as a group - once the customer is connected, other people from the business can be added to the conversation, and the customers will see who are they talking with. This can be used to transfer business conversation to another person, or for escalation - in the same way as with the dedicated support systems.
+
+SimpleX Chat profile with the business address can be used in one of these ways:
+- for small teams it can be managed by one person running the app on their desktop computer, who would respond to customer questions and manually add to the conversation other people in the business, as required.
+- if you have multiple support agents, you can run business profile in CLI client running in cloud VM or on any machine with high speed Internet (see Technical advice below), and they can connect to this client from desktop client, in turns. This is how we use our business profile ourselves, even though it requires some configuration. You can manage 100s of thousands of connected customers in this way.
+- For larger teams, it would be appropriate to have this profile managed by chat bot that can reply to some simple questions, and to add support agents, based on their availability and the questions asked. These scenarios would require programming a chat bot, and we are currently working to simplify it.
+
+In any case, it is important that the client application remains running and connected to the Internet for you to receive support requests.
+
+## Customer broadcasts
+
+While currently supported only via CLI clients (or via chat console in desktop and mobile clients), it can be used to broadcast important announcements to all connected customers. We will be adding this feature to desktop clients soon. We use it to broadcast release updates to a very large number of users who are connected to our own support profile.
+
+## Community groups and promotion in group directory
+
+In addition to providing support to clients individually, you can create a community group, and promote it via our experimental and growing [directory of public groups](https://simplex.chat/docs/directory.md). Community groups require ongoing moderation.
+
+## Limitations
+
+With all advantages in privacy and security of e2e encryption in SimpleX Chat, there are some important limitations:
+- **protecting your data from loss is your responsibility**. This is the price of privacy - if you lose your device, or database passphrase, there is absolutely no way we would be able to support you to recover access. There are ways to work around these limitations.
+- **you cannot access the same profile from multiple devices**. For all communication products it's a basic expectation, and yet there is not a single one that delivered it without some very serious privacy and security compromises. Better solutions are possible, and we will be implementing it, but reasonably secure approach is much more complex to implement than what is affordable at the current stage. You can access mobile or CLI profile from desktop, and the latter allows to use one profile by multiple people in turns, as we explain below.
+- **your owner role in the groups cannot be restored if you lose the device**. The solution is to create owner profiles on multiple devices for all your important groups. This way if you lose device or data for one of profiles, you won't lose control of the group, and you can add a new one. Think about it as about keys to your cryptowallet.
+- **current groups are highly experimental**. Message delivery can be delayed or fail in some cases, lists of members can be out of sync. There are approaches to make them more stable we use for our groups.
+
+## Technical advice
+
+### Running SimpleX Chat in the cloud
+
+To install SimpleX Chat CLI in the cloud, follow this:
+
+1. Create dedicated user for CLI:
+
+   ```sh
+   useradd -m -s /bin/bash simplex-cli
+   ```
+
+2. Create new tmux session
+
+   ```sh
+   tmux new -s simplex-cli
+   ```
+
+3. Login to dedicated user:
+
+   ```sh
+   su - simplex-cli
+   ```
+
+4. Install CLI:
+
+   ```sh
+   curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+   ```
+
+5. Run the CLI:
+
+   ```sh
+   simplex-chat
+   ```
+
+To detach from a running CLI, simply press `Ctrl+B` and then `D`.
+
+To reattach back to CLI, run: `tmux attach -t simplex-cli`.
+
+### Using remote profiles via Desktop app
+
+To use CLI from Desktop app, follow this:
+
+1. Enable Developer tools in desktop app.
+
+2. In the Desktop app, click - `Linked mobile` -> `+ Link a mobile`, choose local address `127.0.0.1`, enter some fixed port (can be any free port, e.g. 12345), and copy the link.
+
+3. In the same machine where Desktop app is running, execute:
+
+   Change `PORT` to port, chosen in the previous step in Desktop app and `SERVER_IP` to your server.
+
+   ```sh
+   ssh -R PORT:127.0.0.1:PORT -N root@SERVER_IP
+   ```
+
+4. In the CLI on the server:
+
+   Change `LINK` to link, copied in the first step and enter the following:
+
+   ```sh
+   /crc LINK
+   ```
+
+   CLI will print verification code:
+
+   ```sh
+   Compare session code with controller and use:
+   /verify remote ctrl ...
+   ```
+  
+   Simply copy the whole line starting with `/verify ...` from the terminal and paste it. Now you can control the CLI from your Desktop app.
+
+## Organizations using SimpleX Chat for customer service, support and sales
+
+Please let us know if you use SimpleX Chat to communicate with your customers and want to be included in this list.
diff --git a/docs/chat-relay.html b/docs/chat-relay.html
index 2cd1553562..c19f78014e 100644
--- a/docs/chat-relay.html
+++ b/docs/chat-relay.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/chat-relay.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/chat-relay.md b/docs/chat-relay.md
new file mode 100644
index 0000000000..c53b1992a0
--- /dev/null
+++ b/docs/chat-relay.md
@@ -0,0 +1,321 @@
+# Hosting your own Chat Relay
+
+Chat relays are used to deliver channel messages in SimpleX Network. Read more about channels in this [whitepaper](https://github.com/simplex-chat/simplex-chat/blob/master/docs/protocol/channels-overview.md) and this [blog post](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html).
+
+A chat relay is the SimpleX Chat CLI (`simplex-chat`) running in relay mode (`--relay`). It has its own profile (a display name and a picture), its own address, and in addition to delivering messages, it can generate data for web previews of the channels it delivers.
+
+This guide explains how to set up a chat relay on a Linux server, how to run it, and (optionally) how to configure [Caddy](https://caddyserver.com) to serve data for channel web previews.
+
+> **Please note**: This guide applies only to SimpleX Chat v7.0.0-beta.4 and later.
+
+## Table of Contents
+
+- [Install the CLI](#install-the-cli)
+- [Run the relay](#run-the-relay)
+   - [Relay options](#relay-options)
+   - [Get the relay address](#get-the-relay-address)
+   - [Run relay commands](#run-relay-commands)
+- [Run with Docker](#run-with-docker)
+- [Channel web previews](#channel-web-previews)
+   - [Relay web options](#relay-web-options)
+   - [Serve the previews with Caddy](#serve-the-previews-with-caddy)
+   - [Reload CORS automatically](#reload-cors-automatically)
+   - [Verify](#verify)
+
+## Install the CLI
+
+The relay is the standard `simplex-chat` CLI binary. Install or update it with the install script:
+
+```sh
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+```
+
+Other options (manual binary download, building from source) are in the [CLI guide](https://simplex.chat/docs/cli.md#download-chat-client).
+
+Copy the installed `simplex-chat` binary to `/usr/local/bin/simplex-chat-relay`. The guide uses that name so the relay is separate from any interactive `simplex-chat` you also run on the server.
+
+Create a dedicated user for the relay (called `relay` below), so it does not run as root and keeps its database in one place:
+
+```sh
+sudo useradd -m relay
+```
+
+The `useradd -m` flag creates its home directory `/home/relay`, where the guide keeps the database and picture. Run the relay commands (the `-e` commands below) as this user, for example with `sudo -u relay ...`; run the `systemd` and Caddy steps as root.
+
+## Run the relay
+
+Run the relay as a `systemd` service. With `--headless` it starts without any interactive prompts. It creates its profile and address on the first start, and writes its output to the journal.
+
+Create a run script `/usr/local/bin/relay-run`:
+
+```sh
+#!/bin/sh
+exec /usr/local/bin/simplex-chat-relay \
+  --relay \
+  --headless \
+  --user-display-name "My Relay" \
+  --user-image-file /home/relay/avatar.png \
+  -d /home/relay/relay
+```
+
+```sh
+chmod +x /usr/local/bin/relay-run
+```
+
+Create `/etc/systemd/system/simplex-relay.service`:
+
+```ini
+[Unit]
+Description=SimpleX Chat relay
+After=network.target
+
+[Service]
+User=relay
+ExecStart=/usr/local/bin/relay-run
+Restart=always
+StandardInput=null
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable and start it:
+
+```sh
+systemctl daemon-reload
+systemctl enable --now simplex-relay
+```
+
+The first start creates the relay profile (with the given name and picture) and its address; later starts reuse them. Both are written to the journal:
+
+```
+Current user: My Relay
+Chat relay address is created:
+https://smp4.simplex.im/r#73iEnnvCqPTVGArCAWUcRaj5hxRb7TbPCSZ2JY2VjCQ
+```
+
+### Relay options
+
+| Option | Purpose |
+| --- | --- |
+| `--relay` | Run as a chat relay. Required. |
+| `--headless` | Don't ask interactive questions; create the profile and address automatically. On first start it also needs `--user-display-name`. |
+| `--user-display-name NAME` | The relay's display name. Creates the profile on first start; on later starts it must match the existing profile. |
+| `--user-image-file FILE` | The relay's picture, from a `.png`, `.jpg` or `.jpeg` file. Applied **only when the profile is created**; ignored afterwards. |
+| `--relay-address-server SERVER` | Create the relay address on a specific SMP server, e.g. `smp://<fingerprint>@smp.example.com`. By default a preset server is used. Requires `--relay`. |
+
+### Get the relay address
+
+The address is created and logged on the first start. Read it from the journal at any time:
+
+```sh
+journalctl -u simplex-relay | grep -A1 "address is created"
+```
+
+### Run relay commands
+
+The service runs headless, so there is no attached terminal to type into. To run a one-off command, stop the service, run the command against the relay's database with `-e`, then start it again. For example, to change the picture (`--user-image-file` only sets it when the profile is first created):
+
+```sh
+systemctl stop simplex-relay
+simplex-chat-relay -d /home/relay/relay -e "/set profile image file /home/relay/new-avatar.png"
+systemctl start simplex-relay
+```
+
+## Run with Docker
+
+The relay can also be built and run with Docker Compose, using PostgreSQL for storage. The files are in [`scripts/relay`](https://github.com/simplex-chat/simplex-chat/tree/master/scripts/relay).
+
+1. Clone the repository and switch to the relay directory:
+
+   ```sh
+   git clone https://github.com/simplex-chat/simplex-chat
+   cd simplex-chat/scripts/relay
+   ```
+
+2. Copy the example environment file, then set `RELAY_NAME`, `RELAY_WEB_DOMAIN` and `POSTGRES_PASSWORD` in it:
+
+   ```sh
+   cp .env.example .env
+   ```
+
+3. Create the directory for the previews and the CORS file, owned by the container's user (UID `1000`):
+
+   ```sh
+   mkdir -p /var/www/relay-web-channels/channel
+   chown -R 1000:1000 /var/www/relay-web-channels
+   chmod 0755 /var/www/relay-web-channels
+   ```
+
+4. Create the output directory for the relay address, then build and start:
+
+   ```sh
+   mkdir -p out && chown 1000:1000 out
+   docker compose build
+   docker compose up -d
+   ```
+
+   The first build compiles from source and takes a while.
+
+5. Read the relay address, written on the first start:
+
+   ```sh
+   cat out/relay-address.txt
+   ```
+
+To give the relay a picture, put a small `.png`/`.jpg`/`.jpeg` file (large images are rejected) next to the compose file and add a `docker-compose.override.yml`:
+
+```yaml
+services:
+  relay:
+    environment:
+      RELAY_IMAGE_FILE: /avatar.png
+    volumes:
+      - ./avatar.png:/avatar.png:ro
+```
+
+To run a one-off command against the relay's database, override the entrypoint:
+
+```sh
+docker compose run --rm --entrypoint sh relay -c \
+  'simplex-chat-relay -d "$DB_CONN" -e "/set profile image file /avatar.png"'
+```
+
+Relay metrics from the database are published by [sql_exporter](https://github.com/burningalchemist/sql_exporter) on `127.0.0.1:9399/metrics`, with the queries in `sql_exporter.yml`.
+
+Relay database live in PostgreSQL docker volume. To print the full path to PostgreSQL database, execute in the host:
+
+```sh
+docker volume inspect simplex-chat-relay_pgdata --format '{{.Mountpoint}}'
+```
+
+## Channel web previews
+
+Chat relays can render recent messages of its public channels as JSON files, which can be served over HTTPS using a web server to create channel web previews. This is optional.
+
+### Relay web options
+
+Add these to the run script (`--relay-web-domain` and `--relay-web-dir` must be given together):
+
+```sh
+  --relay-web-domain relay.example.com \
+  --relay-web-dir /var/www/relay-web-channels/channel \
+  --relay-web-cors-file /var/www/relay-web-channels/cors.conf \
+  --relay-web-interval 30 \
+```
+
+| Option | Purpose |
+| --- | --- |
+| `--relay-web-domain DOMAIN` | Domain the previews are served from. |
+| `--relay-web-dir DIR` | Directory the relay writes channel JSON files to. |
+| `--relay-web-cors-file FILE` | File the relay writes the generated Caddy CORS config to. |
+| `--relay-web-interval SECONDS` | How often previews are regenerated (default `300`). |
+| `--relay-web-item-count COUNT` | Recent messages per channel preview (default `50`). |
+
+Create the web directory, owned by the relay user:
+
+```sh
+mkdir -p /var/www/relay-web-channels/channel
+chmod 0755 /var/www/relay-web-channels
+chown -R relay:relay /var/www/relay-web-channels
+```
+
+Restart the relay so the new flags take effect:
+
+```sh
+systemctl restart simplex-relay
+```
+
+### Serve the previews with Caddy
+
+This section uses [Caddy](https://caddyserver.com) as the web server. Install it (Debian/Ubuntu):
+
+```sh
+sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl &&\
+curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg &&\
+curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list &&\
+sudo apt update && sudo apt install caddy
+```
+
+The relay writes files to `/var/www/relay-web-channels/channel/<id>.json`. Serve them, and import the relay's generated CORS rules, in your `Caddyfile`:
+
+```
+relay.example.com {
+  encode zstd gzip
+
+  handle /channel/* {
+    root * /var/www/relay-web-channels    # files resolve to .../channel/<id>.json
+    file_server
+    import /etc/caddy/simplex-cors.conf
+  }
+}
+```
+
+Keep `root` at the parent directory with a non-stripping `handle`. That is what makes `/channel/<id>.json` resolve to `.../channel/<id>.json`. Do not point `root` at the `channel` subdirectory: the relay's generated CORS matchers are `/channel/*.json`, which only match when the prefix is kept.
+
+```sh
+touch /etc/caddy/simplex-cors.conf      # so the import doesn't fail before the first write
+usermod -aG relay caddy                 # let caddy read the relay user's files
+systemctl restart caddy                 # restart (not reload) to pick up the group
+```
+
+### Reload CORS automatically
+
+The relay updates its CORS file as channels change. Copy it into Caddy's config and reload Caddy whenever it changes.
+
+Create `/usr/local/bin/simplex-cors-sync.sh`:
+
+```sh
+#!/bin/sh
+set -eu
+SRC=/var/www/relay-web-channels/cors.conf
+DST=/etc/caddy/simplex-cors.conf
+[ -f "$SRC" ] || exit 0
+cmp -s "$SRC" "$DST" 2>/dev/null && exit 0
+install -m 0644 "$SRC" "$DST"
+systemctl reload caddy
+logger -t simplex-cors "reloaded caddy"
+```
+
+Create `/etc/systemd/system/simplex-cors-sync.service`:
+
+```ini
+[Unit]
+Description=Sync SimpleX relay CORS config to Caddy
+StartLimitIntervalSec=0
+[Service]
+Type=oneshot
+ExecStart=/usr/local/bin/simplex-cors-sync.sh
+```
+
+Create `/etc/systemd/system/simplex-cors-sync.path` to run the service whenever the relay's CORS file changes:
+
+```ini
+[Unit]
+Description=Watch SimpleX relay CORS config
+After=caddy.service
+[Path]
+PathChanged=/var/www/relay-web-channels/cors.conf
+Unit=simplex-cors-sync.service
+TriggerLimitIntervalSec=0
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable it:
+
+```sh
+chmod +x /usr/local/bin/simplex-cors-sync.sh
+systemctl daemon-reload
+systemctl enable --now simplex-cors-sync.path
+```
+
+### Verify
+
+```sh
+systemctl status simplex-cors-sync.path              # active (waiting)
+ls /var/www/relay-web-channels/channel               # a JSON file appears once a public channel renders
+curl -sI https://relay.example.com/channel/<id>.json | grep -i access-control
+```
+
+The `curl` should return `access-control-*` headers, and the channel link should open a web preview in a browser.
diff --git a/docs/cli.html b/docs/cli.html
index f80fee6a7a..e28d6ff482 100644
--- a/docs/cli.html
+++ b/docs/cli.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/cli.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/cli.md b/docs/cli.md
new file mode 100644
index 0000000000..8d52067e16
--- /dev/null
+++ b/docs/cli.md
@@ -0,0 +1,240 @@
+| Updated 31.01.2023 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/cli.html), [CZ](https://simplex.chat/docs/lang/cs/cli.html), [PL](https://simplex.chat/docs/lang/pl/cli.html) |
+
+# SimpleX Chat terminal (console) app for Linux/MacOS/Windows
+
+## Table of contents
+
+- [Terminal chat features](#terminal-chat-features)
+- [Installation](#🚀-installation)
+  - [Download chat client](#download-chat-client)
+    - [Linux and MacOS](#linux-and-macos)
+    - [Windows](#windows)
+  - [Build from source](#build-from-source)
+    - [Using Docker](#using-docker)
+    - [Using Haskell in any OS](#in-any-os)
+- [Usage](#usage)
+  - [Running the chat client](#running-the-chat-client)
+  - [Access messaging servers via Tor](#access-messaging-servers-via-tor-beta)
+  - [How to use SimpleX chat](#how-to-use-simplex-chat)
+  - [Groups](#groups)
+  - [Sending files](#sending-files)
+  - [User contact addresses](#user-contact-addresses)
+  - [Access chat history](#access-chat-history)
+
+## Terminal chat features
+
+- 1-to-1 chat with multiple people in the same terminal window.
+- Group messaging.
+- Sending files to contacts and groups.
+- User contact addresses - establish connections via multiple-use contact links.
+- Messages persisted in a local SQLite database.
+- Auto-populated recipient name - just type your messages to reply to the sender once the connection is established.
+- Demo SMP servers available and pre-configured in the app - or you can [deploy your own server](https://github.com/simplex-chat/simplexmq#using-smp-server-and-smp-agent).
+- No global identity or any names visible to the server(s), ensuring full privacy of your contacts and conversations.
+- Two layers of E2E encryption (double-ratchet for duplex connections, using X3DH key agreement with ephemeral Curve448 keys, and NaCl crypto_box for SMP queues, using Curve25519 keys) and out-of-band passing of recipient keys (see [How to use SimpleX chat](#how-to-use-simplex-chat)).
+- Message integrity validation (via including the digests of the previous messages).
+- Authentication of each command/message by SMP servers with automatically generated Ed448 keys.
+- TLS 1.3 transport encryption.
+- Additional encryption of messages from SMP server to recipient to reduce traffic correlation.
+
+Public keys involved in key exchange are not used as identity, they are randomly generated for each contact.
+
+See [Encryption Primitives Used](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md#encryption-primitives-used) for technical details.
+
+<a name="🚀-installation"></a>
+
+## 🚀 Installation
+
+### Download chat client
+
+#### Linux and MacOS
+
+To **install** or **update** `simplex-chat`, you should run the install script. To do that, use the following cURL or Wget command:
+
+```sh
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+```
+
+```sh
+wget -qO- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+```
+
+Once the chat client downloads, you can run it with `simplex-chat` command in your terminal.
+
+Alternatively, you can manually download the chat binary for your system from the [latest stable release](https://github.com/simplex-chat/simplex-chat/releases) and make it executable as shown below.
+
+```sh
+chmod +x <binary>
+mv <binary> ~/.local/bin/simplex-chat
+```
+
+(or any other preferred location on `PATH`).
+
+On MacOS you also need to [allow Gatekeeper to run it](https://support.apple.com/en-us/HT202491).
+
+#### Windows
+
+```sh
+move <binary> %APPDATA%/local/bin/simplex-chat.exe
+```
+
+### Build from source
+
+> **Please note:** to build the app use source code from [stable branch](https://github.com/simplex-chat/simplex-chat/tree/stable).
+
+#### Using Docker
+
+On Linux, you can build the chat executable using [docker build with custom output](https://docs.docker.com/engine/reference/commandline/build/#custom-build-outputs):
+
+```shell
+git clone git@github.com:simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+DOCKER_BUILDKIT=1 docker build --output ~/.local/bin .
+```
+
+> **Please note:** If you encounter `` version `GLIBC_2.28' not found `` error, rebuild it with `haskell:8.10.7-stretch` base image (change it in your local [Dockerfile](https://github.com/simplex-chat/simplex-chat/blob/stable/Dockerfile)).
+
+#### In any OS
+
+1. Install [Haskell GHCup](https://www.haskell.org/ghcup/), GHC 9.6.3 and cabal 3.10.1.0:
+
+```shell
+curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+```
+
+You can use `ghcup tui` to check or add GHC and cabal versions.
+
+2. Clone the source code:
+
+```shell
+git clone git@github.com:simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+# or to build a specific version:
+# git checkout v5.3.0-beta.8
+```
+
+`master` is a development branch, it may contain unstable code.
+
+3. Prepare the system:
+
+On Linux:
+
+```shell
+apt-get update && apt-get install -y build-essential libgmp3-dev zlib1g-dev
+cp scripts/cabal.project.local.linux cabal.project.local
+```
+
+On Mac:
+
+```
+brew install openssl@3.0
+cp scripts/cabal.project.local.mac cabal.project.local
+```
+
+You may need to amend cabal.project.local to point to the actual openssl location.
+
+4. Build the app:
+
+```shell
+cabal update
+cabal install simplex-chat
+```
+
+## Usage
+
+### Running the chat client
+
+To start the chat client, run `simplex-chat` from the terminal.
+
+By default, app data directory is created in the home directory (`~/.simplex`, or `%APPDATA%/simplex` on Windows), and two SQLite database files `simplex_v1_chat.db` and `simplex_v1_agent.db` are initialized in it.
+
+To specify a different file path prefix for the database files use `-d` command line option:
+
+```shell
+$ simplex-chat -d alice
+```
+
+Running above, for example, would create `alice_v1_chat.db` and `alice_v1_agent.db` database files in current directory.
+
+Three default SMP servers are hosted on Linode - they are [pre-configured in the app](https://github.com/simplex-chat/simplex-chat/blob/stable/src/Simplex/Chat/Options.hs#L42).
+
+If you deployed your own SMP server(s) you can configure client via `-s` option:
+
+```shell
+$ simplex-chat -s smp://LcJUMfVhwD8yxjAiSaDzzGF3-kLG4Uh0Fl_ZIjrRwjI=@smp.example.com
+```
+
+Base64url encoded string preceding the server address is the server's offline certificate fingerprint which is validated by client during TLS handshake.
+
+You can still talk to people using default or any other server - it only affects the location of the message queue when you initiate the connection (and the reply queue can be on another server, as set by the other party's client).
+
+Run `simplex-chat -h` to see all available options.
+
+### Access messaging servers via Tor
+
+Install Tor and run it as SOCKS5 proxy on port 9050, e.g. on Mac you can:
+
+```
+brew install tor
+brew services start tor
+```
+
+Use `-x` option to access servers via Tor:
+
+```
+simplex-chat -x
+```
+
+You can also use option `--socks-proxy=ipv4:port` or `--socks-proxy=:port` to configure host and port of your SOCKS5 proxy, e.g. if you are running it on some other host or port.
+
+### How to use SimpleX chat
+
+Once you have started the chat, you will be prompted to specify your "display name" and an optional "full name" to create a local chat profile. Your display name is an alias for your contacts to refer to you by - it is not unique and does not serve as a global identity. If some of your contacts chose the same display name, the chat client adds a numeric suffix to their local display name.
+
+The diagram below shows how to connect and message a contact:
+
+<div align="center">
+  <img align="center" src="../images/how-to-use-simplex.svg">
+</div>
+
+Once you've set up your local profile, enter `/c` (for `/connect`) to create a new connection and generate an invitation. Send this invitation to your contact via any other channel.
+
+You are able to create multiple invitations by entering `/connect` multiple times and sending these invitations to the corresponding contacts you'd like to connect with.
+
+The invitation can only be used once and even if this is intercepted, the attacker would not be able to use it to send you the messages via this queue once your contact confirms that the connection is established. See agent protocol for explanation of [invitation format](https://github.com/simplex-chat/simplexmq/blob/master/protocol/agent-protocol.md#connection-request).
+
+The contact who received the invitation should enter `/c <invitation>` to accept the connection. This establishes the connection, and both parties are notified.
+
+They would then use `@<name> <message>` commands to send messages. You may also just start typing a message to send it to the contact that was the last.
+
+Use `/help` in chat to see the list of available commands.
+
+### Groups
+
+To create a group use `/g <group>`, then add contacts to it with `/a <group> <name>`. You can then send messages to the group by entering `#<group> <message>`. Use `/help groups` for other commands.
+
+![simplex-chat](https://simplex.chat/images/groups.gif)
+
+> **Please note**: the groups are not stored on any server, they are maintained as a list of members in the app database to whom the messages will be sent.
+
+### Sending files
+
+You can send a file to your contact with `/f @<contact> <file_path>` - the recipient will have to accept it before it is sent. Use `/help files` for other commands.
+
+![simplex-chat](https://simplex.chat/images/files.gif)
+
+You can send files to a group with `/f #<group> <file_path>`.
+
+### User contact addresses
+
+As an alternative to one-time invitation links, you can create a long-term address with `/ad` (for `/address`). The created address can then be shared via any channel, and used by other users as a link to make a contact request with `/c <user_contact_address>`.
+
+You can accept or reject incoming requests with `/ac <name>` and `/rc <name>` commands.
+
+User address is "long-term" in a sense that it is a multiple-use connection link - it can be used until it is deleted by the user, in which case all established connections would still remain active (unlike how it works with email, when changing the address results in people not being able to message you).
+
+Use `/help address` for other commands.
+
+![simplex-chat](https://simplex.chat/images/user-addresses.gif)
diff --git a/docs/code_of_conduct.html b/docs/code_of_conduct.html
index 8a592f98cf..29546c7042 100644
--- a/docs/code_of_conduct.html
+++ b/docs/code_of_conduct.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/code_of_conduct.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/code_of_conduct.md b/docs/code_of_conduct.md
new file mode 100644
index 0000000000..a5283c1459
--- /dev/null
+++ b/docs/code_of_conduct.md
@@ -0,0 +1,19 @@
+# Code of Conduct
+
+We’re building great software through **engineering excellence**, **prioritizing users’ needs**, and **collaboration based on merit and respect**.
+
+Everyone is welcome to contribute by following these guidelines:
+
+**Contribution Acceptance**: We evaluate contributions iteratively based on quality, user needs, and project goals. Discuss plans early to align efforts, as acceptance depends on refinement guided by maintainers’ feedback.
+
+**Equal Treatment**: All contributors are valued equally, regardless of background or beliefs. Discrimination or policies favoring specific groups are not allowed.
+
+**Constructive Criticism**: Share clear, evidence-based and respectful criticism to improve the project.
+
+**Focus on Work**: Avoid fear, uncertainty, doubt (FUD), or personal attacks.
+
+**Relevant Discussions**: Stick to software and project goals, avoiding politics, ideology, or unrelated topics.
+
+Violations may lead to warnings, temporary bans, or removal, at maintainers’ discretion.
+
+Let’s create great software together!
diff --git a/docs/contributing.html b/docs/contributing.html
index efbfa64f02..4c7cfbdd6e 100644
--- a/docs/contributing.html
+++ b/docs/contributing.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/contributing.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/contributing.md b/docs/contributing.md
new file mode 100644
index 0000000000..771e123f86
--- /dev/null
+++ b/docs/contributing.md
@@ -0,0 +1,155 @@
+| Updated 25.07.2025 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/contributing.html), [CZ](https://simplex.chat/docs/lang/cs/contributing.html), [PL](https://simplex.chat/docs/lang/pl/contributing.html) |
+
+# Contributing guide
+
+## Focus on user problems
+
+We do not make code changes to improve code - any change must address a specific user problem or request.
+
+## Discuss the plans as early as possible
+
+Please discuss the problem you want to solve and your detailed implementation plan with the project team prior to contributing, to avoid wasted time and additional changes. Acceptance of your contribution depends on your willingness and ability to iterate the proposed contribution to achieve the required quality level, coding style, test coverage, and alignment with user requirements as they are understood by the project team.
+
+## Follow project structure, coding style and approaches
+
+./contributing/PROJECT.md has information about the structure of this `simplex-chat` repository.
+
+./contributing/CODE.md has details about general requirements common for `simplexmq` and `simplex-chat` repositories.
+
+These files can be used with LLM prompts, e.g. if you use Claude Code you can create CLAUDE.md file in project root importing content from these files:
+
+```markdown
+@README.md
+@docs/CONTRIBUTING.md
+@docs/contributing/PROJECT.md
+@docs/contributing/CODE.md
+```
+
+For Android/Desktop and iOS apps you can additionally import `apps/multiplatform/README.md` and `apps/ios/README.md`.
+
+## Compiling with SQLCipher encryption enabled
+
+Add `cabal.project.local` to project root with the location of OpenSSL headers and libraries and flag setting encryption mode:
+
+```
+cp scripts/cabal.project.local.mac cabal.project.local
+# or
+# cp scripts/cabal.project.local.linux cabal.project.local
+```
+
+## OpenSSL on MacOS
+
+MacOS comes with LibreSSL as default, OpenSSL must be installed to compile SimpleX from source.
+
+OpenSSL can be installed with `brew install openssl@3.0`
+
+You will have to add `/opt/homebrew/opt/openssl@3.0/bin` to your PATH in order to have things working properly
+
+
+## Project branches
+
+**In simplex-chat repo**
+
+- `stable` - stable release of the apps, can be used for updates to the previous stable release (GHC 9.6.3).
+
+- `stable-android` - used to build stable Android core library with Nix (GHC 8.10.7) - only for Android armv7a.
+
+- `master` - branch for beta version releases (compatible with both GHC 9.6.3 and 8.10.7).
+
+- `master-android` - used to build beta Android core library with Nix (GHC 8.10.7) - only for Android armv7a.
+
+**In simplexmq repo**
+
+- `master` - compatible with both GHC 9.6.3 and 8.10.7.
+
+## Development & release process
+
+1. Make PRs to `master` branch _only_ for both simplex-chat and simplexmq repos.
+
+2. To build core libraries for Android, iOS and Windows:
+- merge `master` branch to `master-android` branch.
+- push to GitHub.
+
+3. All libraries should be built from `master` branch, Android armv7a - from `master-android` branch.
+
+4. To build Desktop and CLI apps, make tag in `master` branch, APK files should be attached to the release.
+
+5. After the public release to App Store and Play Store, merge:
+- `master` to `stable`
+- `master` to `master-android` (and compile/update code)
+- `master-android` to `stable-android`
+
+6. Independently, `master` branch of simplexmq repo should be merged to `stable` branch on stable releases.
+
+## Branches and PRs
+
+Use change scope (or comma separated scopes) as the first word in the PR names, followed by the colon. Commit name itself should be lowercase, in present tense.
+
+The PR names in simplex-chat repo are used in release notes, they should describe the solved problem and not the change. Possible PR scopes:
+- ios
+- android
+- desktop
+- core
+- docs
+- website
+- ci
+
+We squash PRs, do not rewrite branch history after the review.
+
+For some complex features we create feature branches that will be merged once ready - do not make commits directly to them, make PRs to feature branches.
+
+## Differences between GHC 8.10.7 and GHC 9.6.3
+
+1. The main difference is related to `DuplicateRecordFields` extension.
+
+It is no longer possible in GHC 9.6.3 to specify type when using selectors, instead OverloadedRecordDot extension and syntax are used that need to be removed in GHC 8.10.7:
+
+```haskell
+{-# LANGUAGE DuplicateRecordFields #-}
+-- use this in GHC 9.6.3 when needed
+{-# LANGUAGE OverloadedRecordDot #-}
+
+-- GHC 9.6.3 syntax
+let x = record.field
+
+-- GHC 8.10.7 syntax removed in GHC 9.6.3
+let x = field (record :: Record)
+```
+
+It is still possible to specify type when using record update syntax, use this pragma to suppress compiler warning:
+
+```haskell
+-- use this in GHC 9.6.3 when needed
+{-# OPTIONS_GHC -fno-warn-ambiguous-fields #-}
+
+let r' = (record :: Record) {field = value}
+```
+
+2. Most monad functions now have to be imported from `Control.Monad`, and not from specific monad modules (e.g. `Control.Monad.Except`).
+
+```haskell
+-- use this in GHC 9.6.3 when needed
+import Control.Monad
+```
+
+[This PR](https://github.com/simplex-chat/simplex-chat/pull/2975/files) has all the differences.
+
+
+## Improving compatibility between versions for remote desktop connection
+
+UI already can handle failed JSON conversions of chats and chat items, and it helps both debugging and downgrading.
+
+While we can increase versions for remote connections to make different versions incompatible, it degrades remote connection UX, as in many cases users can't upgrade mobile or desktop apps at the same time because of different release cycles.
+
+It is especially problematic for Android app users, as they can only downgrade via Export/Import - older version can't be installed on top of newer version.
+
+PR #6105 improved it by:
+- adding CInfoInvalidJSON constructor, so that chats that cannot be parsed will show as "invalid chat" via remote connection (as when UI has field not present in API),
+- changing JSON parsing for CIContent, so that it falls back to CIInvalidJSON in platform-specific JSON parser.
+
+To avoid "invalid" chats in the list we need to maintain forward compatibility on JSON encoding level of AChat type and subtypes:
+- add new fields as optional to these types,
+- add `omittedField` method to FromJSON instances of types of new fields to provide a default value, where appropriate,
+- define primitive non-optional fields as newtype with `omittedField` in JSON instance.
+
+To avoid fallback to invalid JSON in chat items we should do the same for ChatItem type and subtypes. It's especially important when adding fields to types used for all CIContent, as otherwise all items will be broken.
diff --git a/docs/directory.html b/docs/directory.html
index 9a809a0dd6..4bd39a0258 100644
--- a/docs/directory.html
+++ b/docs/directory.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/directory.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/directory.md b/docs/directory.md
new file mode 100644
index 0000000000..e0ec12fa43
--- /dev/null
+++ b/docs/directory.md
@@ -0,0 +1,93 @@
+# SimpleX Directory
+
+You can use SimpleX Directory to discover the groups created and registered by other users.
+
+## Searching for groups
+
+SimpleX Directory is available at [simplex.chat/directory](https://simplex.chat/directory/) or via this [onion link](http://isdb4l77sjqoy2qq7ipum6x3at6hyn3jmxfx4zdhc72ufbmuq4ilwkqd.onion/directory/).
+
+You can also connect to SimpleX Directory via [this address](https://smp4.simplex.im/a#lXUjJW5vHYQzoLYgmi8GbxkGP41_kjefFvBrdwg-0Ok) and send the message containing the words you want to find in the group name or welcome message. You will receive up to 10 groups with the largest number of members in the response, together with the links to join these groups.
+
+Please note that your search queries can be kept by the bot as the conversation history, but you can use incognito mode when connecting to the bot, to avoid correlation with any other communications. See [Privacy policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md) for more details.
+
+## Adding groups to the directory
+
+
+### How to add a group
+
+To add a group you must be its owner. Once you connect to the directory service and send `/help`, the service will guide you through the process.
+
+1. Invite SimpleX Service Directory to the group as `admin` member. You can also set the role to `admin` after inviting the directory service. The member who invited the directory service will be the owner of the group record in the directory service.
+
+The directory service needs to be `admin` to provide a good user experience of joining the group, as it will create a new link to join the group, which is expected to be online 99% of the time.
+
+2. The group will need to be approved by the directory service admins. The directory service creates the link to join the group when the group is approved, and sends it to you.
+
+The group is usually approved within 24 hours. Please see below which groups can be added.
+
+Once the group is approved, it will appear in search results together with the link to join it. We recommend adding this link to the group welcome message - adding or removing it does not require a new approval.
+
+You can list all the groups you submitted by sending `/list` to the directory service.
+
+### How to remove the group from the directory
+
+Changing the group profile (e.g., the group name, image, or the text of the welcome message) will remove the group from the search results until the group is approved again by the directory service admins. Adding or removing the directory link in the welcome message does not require a new approval.
+
+If it is undesirable that the service cannot be found in search during this time, please coordinate the time of this change with the directory service admins for quick approval.
+
+Changing the role of the directory service will temporarily remove the group from the search results, and unless you changed the role to the `owner`, it will also permanently disrupt the members that were in the process of connecting to other members via the directory service.
+
+To remove the group from the directory, send `/delete <ID>:<name>` to the directory service, with the ID and name shown by `/list`. You can also remove the directory service from the group - the group will be permanently removed from the search results.
+
+Removing the group does not prevent you from registering the group again in the future.
+
+### Why limit which groups can be added
+
+The reason to restrict the acceptable content is to have a better experience for a wider range of the users, and to comply with the content policies of app distribution channels (App Store, Play Store, etc.), once the directory service is available via the app without additional configuration. To achieve that, the content in the listed groups should be restricted to be generally appropriate.
+
+Doesn't it go against the idea of decentralization and freedom of speech?
+
+We believe it does not, because:
+
+1. The service only restricts the content in the groups that you choose to register – we have no register of all existing groups, and no access to their content.
+2. The service itself is open-source, and can be self-hosted, so anybody can run an alternative directory service with the different content policies, or without any policies at all.
+3. Freedom of speech should respect legal rights and freedoms of others, so agreeing some boundaries seems necessary.
+
+### Which groups can be added
+
+The below is not the final policy, it is a work in progress.
+
+Currently, the group registration is limited and manual, as we have limited resources to evaluate the content of the groups, so the initial content policy is quite restrictive - we believe it is better to be able to extend what is allowed, than to have to reduce it.
+
+To be "listed in the directory" <sup>\*</sup>, the group must have at least 10 members. Both the group and group owner profiles must include relevant, appropriate, non-offensive avatar images, that do not use the existing trademarks.
+
+Please ONLY submit the groups on the following subjects:
+- communications solutions and providers (messengers, social networks, Internet, etc.)
+- privacy and security
+- cryptocurrencies
+- product and software development
+- science and technology
+- media and entertainment: books, music, movies and games
+- politics, society, culture and education
+
+The content in the group must be "appropriate" for the general audience, starting from 12 years old.
+
+The content in the listed groups must:
+- be legal for the jurisdiction you are in.
+- NOT contain spam and advertising.
+- NOT contain violence, calls for violence, calls for public demonstrations, or any other disturbing content.
+- NOT contain pornography, nudity, erotic or any sex-related content.
+- NOT contain racism, hate speech, or any other content that promotes discrimination.
+- NOT contain information about drugs, alcohol, or any other substances.
+- NOT contain [NSFW](https://en.wikipedia.org/wiki/Not_safe_for_work) content.
+- NOT be offensive – this needs to be clarified.
+
+Group owners are expected to moderate the content in the groups, if members post inappropriate or excessive amount of content and group owners do not moderate it, the group is likely to be removed from the directory.
+
+We reserve the right to not accept the group listing in the directory or cancel its listing, and there may be cases when we can't provide an explanation. We will certainly try to avoid it by communicating with the group owners first.
+
+The combination of display name and full name has to be unique for the listed groups. If a group uses the name or logo of SimpleX, SimpleX network or SimpleX Chat it must be consistent with [Permitted Uses of SimpleX trademark](https://simplex.chat/docs/trademark.md).
+
+Once the group is listed in the directory, the bot will invite you to join the group of the group owners, where you can send any ideas or suggestions for how the groups functionality should evolve, and help steer both the product and the policies.
+
+<sup>\*</sup> "listed" means discoverable via search or any other directory service functions by any connected users other than the user who submitted the registration
diff --git a/docs/glossary.html b/docs/glossary.html
index 5ae47af48b..07be96037b 100644
--- a/docs/glossary.html
+++ b/docs/glossary.html
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+# Glossary
+
+Choosing a private messenger requires the understanding of many technical terms, that many users, even quite technical, often misunderstand. This list is aiming to fill this knowledge gap. Please suggest any changes or additions.
+
+While this glossary aims to be factual and objective, it is not completely unbiased. We designed SimpleX to be the most private, secure and resilient communication network, and some definitions reflect this view.
+
+## 2-factor key exchange
+
+The ability of communication service to ensure the security of the [key agreement protocol](#key-agreement-protocol) against [man-in-the-middle](#man-in-the-middle-attack).
+
+## Address portability
+
+Similarly to [phone number portability](https://en.wikipedia.org/wiki/Local_number_portability) (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many [federated networks](#federated-network) support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.
+
+## Anonymous credentials
+
+The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.
+
+[Digital credential on Wikipedia](https://en.wikipedia.org/wiki/Digital_credential)
+
+## Blockchain
+
+In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of [Merkle directed acyclic graphs](#merkle-directed-acyclic-graph).
+
+In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some [consensus protocol](https://en.wikipedia.org/wiki/Consensus_(computer_science)).
+
+[Wikipedia](https://en.wikipedia.org/wiki/Blockchain)
+
+## Break-in recovery
+
+[Post-compromise security](#post-compromise-security).
+
+## Centralized network
+
+Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.
+
+## Content padding
+
+[Message padding](#message-padding).
+
+## Decentralized network
+
+Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.
+
+The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.
+
+## Defense in depth
+
+Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.
+
+In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.
+
+SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:
+- double ratchet algorithm for [end-to-end encryption](#end-to-end-encryption) with [perfect forward secrecy](#forward-secrecy) and [post-compromise security](#post-compromise-security),
+- additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,
+- TLS with only strong ciphers allowed,
+- mitigation of [man-in-the-middle attack](#man-in-the-middle-attack) on client-server connection via server offline certificate verification,
+- mitigation of replay attacks via signing over transport channel binding,
+- multiple layers of [message padding](#message-padding) to reduce efficiency of traffic analysis,
+- mitigation of [man-in-the-middle attack](#man-in-the-middle-attack) on client-client out-of-band channel when sending the invitation,
+- rotation of delivery queues to reduce efficiency of traffic analysis,
+- etc.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Defence_in_depth)
+
+## Double ratchet algorithm
+
+It is used by two parties to exchange [end-to-end encrypted](#end-to-end-encryption) messages. The parties will use some [key agreement protocol](#key-agreement-protocol) to agree on the initial shared secret key.
+
+Double Ratchet algorithm provides [perfect forward secrecy](#forward-secrecy) and [post-compromise security](#post-compromise-security). It is [designed by Signal](https://signal.org/docs/specifications/doubleratchet), and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.
+
+## End-to-end encryption
+
+A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.
+
+End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See [key agreement protocol](#key-agreement-protocol). This key exchange can be compromised via [man-in-the-middle attack](#man-in-the-middle-attack), particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.
+
+[Wikipedia](https://en.wikipedia.org/wiki/End-to-end_encryption)
+
+## Federated network
+
+Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.
+
+The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no [address portability](#address-portability), 3) the security and privacy are inevitably worse than with the centralized networks.
+
+[Federation on Wikipedia](https://en.wikipedia.org/wiki/Federation_(information_technology))
+
+## Forward secrecy
+
+Also known as perfect forward secrecy, it is a feature of a [key agreement protocol](#key-agreement-protocol) that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Forward_secrecy)
+
+## Key agreement protocol
+
+Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for [end-to-end encryption](#end-to-end-encryption) to work. Unless it is possible to secure the key exchange via [some second factor](#2-factor-key-exchange), e.g. security code verification, it can be vulnerable to [man-in-the-middle attack](#man-in-the-middle-attack).
+
+[Wikipedia](https://en.wikipedia.org/wiki/Key-agreement_protocol)
+
+## Key exchange
+
+[Key agreement protocol](#key-agreement-protocol).
+
+## Man-in-the-middle attack
+
+The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.
+
+This attack can be used to compromise [end-to-end encryption](#end-to-end-encryption) by intercepting public keys during [key exchange](#key-agreement-protocol), substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.
+
+Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.
+
+To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Man-in-the-middle_attack).
+
+## Merkle directed acyclic graph
+
+Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.
+
+This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with [blockchain](#blockchain).
+
+The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in [IPFS](https://en.wikipedia.org/wiki/InterPlanetary_File_System) and will be used in decentralized SimpleX groups.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Merkle_tree).
+
+## Message padding
+
+Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Padding_(cryptography)).
+
+## Onion routing
+
+A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.
+
+The most widely used onion network is [Tor](https://en.wikipedia.org/wiki/Tor_(network)).
+
+Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Onion_routing)
+
+## Overlay network
+
+Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.
+
+SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Overlay_network)
+
+## Non-repudiation
+
+The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to [repudiation](#repudiation). While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Non-repudiation)
+
+## Pairwise pseudonymous identifier
+
+Generalizing [the definition](https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier) from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.
+
+In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.
+
+## Peer-to-peer
+
+Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.
+
+The advantage is that the participants do not depend on any servers. There are [multiple downsides](https://simplex.chat/docs/simplex.md#comparison-with-p2p-messaging-protocols) to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with [proxied P2P](#proxied-peer-to-peer) architecture.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Peer-to-peer).
+
+## Perfect forward secrecy
+
+[Forward secrecy](#forward-secrecy).
+
+## Post-compromise security
+
+The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. [Double-ratchet algorithm](#double-ratchet-algorithm) has this quality.
+
+## Post-quantum cryptography
+
+Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is *proven* to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Post-quantum_cryptography)
+
+## Privacy
+
+Someone's right to keep (or the state when they keep) their personal matters and relationships secret (e.g., [Cambridge dictionary](https://dictionary.cambridge.org/dictionary/english/privacy)). Privacy of communication systems should include the privacy of connections and meta-data, not only the privacy of the content of messages. [End-to-end encryption](#end-to-end-encryption) on its own does not provide privacy, as it only protects message content and not connections or meta-data.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Privacy)
+
+## Proxied peer-to-peer
+
+Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.
+
+## Recovery from compromise
+
+[Post-compromise security](#post-compromise-security).
+
+## Repudiation
+
+The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.
+
+See also [non-repudiation](#non-repudiation).
+
+## User identity
+
+In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see [this comparison](https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols).
diff --git a/docs/guide/app-settings.html b/docs/guide/app-settings.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/app-settings.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
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+# App settings
+
+## Opening the app settings
+
+To open app settings:
+
+- Open the app.
+- Tap on your user profile image in the upper left-hand of the screen.
+- If you have more than one profile, tap the current profile again or choose Settings.
+
+## Your profile settings
+
+This section is labelled **"You"** in the app settings.
+
+### Your active profile
+
+Tap on your avatar/name to update your current profile names and avatar.
+
+Display name cannot have any spaces and it is recommended to use latin characters and numbers to make it easier to type these names to the users who use [SimpleX Chat for the terminal](https://simplex.chat/docs/cli.md) (CLI).
+
+**Please note**: When you save your profile, the update will be sent to all your contacts (excluding the contacts with whom your incognito profiles were shared). If you have a large number of contacts it can take several seconds.
+
+### Your chat profiles
+
+This page allows adding and configuring your chat profiles. Please see [Your chat profiles](https://simplex.chat/docs/guide/chat-profiles.md) for more details.
+
+### Incognito
+
+This feature is unique to SimpleX Chat – it is independent from chat profiles.
+
+When "Incognito” is turned on, your current profile name and image are NOT shared with your new contacts. It allows connections with other people without any shared data – when you make new connections or join groups via a link a new random profile name will be generated for each contact or group.
+
+Please read more in [this post](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#incognito-mode).
+
+### Your SimpleX contact address
+
+<img src="../../blog/images/20221108-address1.png" width="288">    <img src="../../blog/images/20221108-address2.png" width="288">
+
+This page allows you to create a long term address that can be used by other people to connect with you. Unlike 1-time invitation links, these addresses can be used many times, that makes them good to share online, e.g. on other social media platforms.
+
+When people connect to you via this address, you will receive a connection request that you can accept or reject. You can configure an automatic acceptance of connection request and an automatic welcome message that will be sent to the new contacts.
+
+If you start receiving too many requests via this address it is always safe to remove it – all the connections you created via this address will remain active, as this address is not used to deliver the messages.
+
+See the comparison with [1-time invitation links](https://simplex.chat/docs/guide/making-connections.md#comparison-of-1-time-invitation-links-and-simplex-contact-addresses).
+
+Read more in [this post](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md#auto-accept-contact-requests).
+
+### Chat preferences
+
+This page allows to configure the chat preferences that would apply to all contacts - they can be changed separately for each contact:
+
+- _disappearing messages_ - to allow disappearing messages in the conversations with you, only if your contacts allow them.
+- _delete for everyone_ - to allow irreversible message deletion (by default messages are marked as deleted, not fully deleted). "Yes" setting would allow it only if they allow it for you, and "Always" - even if they don't allow.
+- _voice messages_ - to allow sending voice messages.
+
+To set chat preferences in each contact, tap contact name on top of the conversation and then choose "Contact preferences".
+
+Group owners can set similar preferences for their groups, when the group is created or later: tap group name on top of the conversation and then choose "Group preferences".
+
+## Your app settings
+
+This section is labelled **"Settings"** in the app settings.
+
+### Notifications
+
+This page allows to configure the notifications mode: instant, periodic or only when the app is running. There are some differences in how these options work on iOS and Android. Please read more in [this post](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md) about how notifications work.
+
+You can also configure whether the message preview is shown when the message arrives.
+
+**Please note**: For instant and periodic notifications to work on Android, you need to disable power optimization when prompted by the app, or later via the settings. Also, some variants of Android system require additional settings, for example MIU system on Xiaomi phones requires to enable "Auto start" for the app for the notification service to work. Please read [Don't kill my app](https://dontkillmyapp.com/) guide for any settings that may be required on your device.
+
+Also, currently instant notifications have the highest battery consumption - we are working to reduce it to be less or the same as for periodic notifications.
+
+### Network & servers
+
+This page allows to configure your own SMP relays and change other network settings.
+
+<img src="../../blog/images/20230204-transport.png" width="288">
+
+#### SMP servers
+
+<img src="../../blog/images/20221206-server1.png" width="288">    <img src="../../blog/images/20221206-server2.png" width="288">    <img src="../../blog/images/20221206-server3.png" width="288">
+
+By default, the app has preset relays configured – you can change them to your own.
+
+This page also allows testing the connection with the servers.
+
+Read more in [this post](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#smp-servers-configuration-and-password).
+
+#### Use SOCKS proxy (Android only)
+
+This option makes the app connect via a SOCKS proxy that should be provided by some other app running on your device.
+
+The most typical use for this is to run Orbot app that provides a SOCKS proxy to connect via Tor network, but it can be some other app and it can proxy connections via some other overlay network.
+
+#### Use .onion hosts
+
+##### Android
+
+**Use .onion hosts** option is only available when **Use SOCKS proxy** is enabled. You can choose:
+
+- _no_: never use .onion hosts. Choose this option if your SOCKS proxy does not connect via Tor network.
+- _when available_ (default): when SOCKS proxy is enabled the app assumes that it provides connections via Tor network and use .onion host addresses when SMP relays include them in their configuration.
+- _required_: always use .onion hosts. Choose this option if your SOCKS proxy connects via Tor network and you want to avoid connections without Tor. In this case, if the SMP relay address does not include .onion host, the connection will fail.
+
+##### iOS
+
+<img src="../../blog/images/20220901-onion1.png" width="330">   <img src="../../blog/images/20220901-onion2.png" width="330">
+
+While iOS does not support SOCKS proxies, you can install Orbot app that works as VPN provider. You can choose:
+
+- _no_ (default): do not use .onion hosts. Choose this option if you do not use Orbot or if you use VPN that proxies connections via some other overlay network.
+- _when available_: use .onion host addresses when SMP relays include them in their configuration. Orbot VPN must be enabled for this option to work.
+- _required_: always use .onion hosts. Choose this option if you use Orbot VPN and you want to avoid connections without Tor. In this case, if the SMP relay address does not include .onion host, the connection will fail. If you use this option, you can enable "Disable Orbot for non-onion traffic" option in Orbot settings making the rest of your device traffic to not use Tor.
+
+**Please note** VPN on iOS can send some traffic to the usual network, if, for example, VPN app crashes. You can configure enable always-on VPN mode on managed iOS devices, but this is not applicable to most individual devices.
+
+#### Transport isolation (BETA)
+
+This option is only available if you have enabled developer tools.
+
+Please read the details in [this post](https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md#transport-isolation).
+
+#### Advanced network settings
+
+<img src="../../blog/images/20220808-network.png" width="330">
+
+If your network is slow, and connections to the servers keep failing (you would see a spinner on your contacts), please increase TCP and protocol timeouts in this page.
+
+### Privacy and security
+
+#### SimpleX Lock
+
+SimpleX Lock when enabled requires to pass the device authentication when you open the app or use some security- or privacy-sensitive features.
+
+You will be offered to enable it after you open the app a few times.
+
+To enable it later:
+
+- [Open the app settings](#opening-the-app-settings).
+- Tap on "Privacy & security".
+- Toggle on "SimpleX Lock" slider.
+- Confirm your phone credentials.
+
+Done! Now you will be required to authenticate when you start or resume the app after 30 seconds in background.
+
+#### Protect app screen
+
+<img src="../../blog/images/20221206-protect.png" width="330">
+
+This option hides the app screen in recent apps - it is enabled by default. On Android it also prevents screenshots.
+
+#### Auto Accept Images
+
+Auto-accepting images may reduce privacy – your contacts will know you are online.
+
+- [Open the app settings](#opening-the-app-settings).
+- Tap on "Privacy & security".
+- Toggle on "Auto-accept images".
+
+#### Send Link Previews
+
+Enabling sending link previews may reduce privacy – your app will be loading link preview from the website.
+
+- [Open the app settings](#opening-the-app-settings).
+- Tap on "Privacy & security".
+- Toggle on "Send link previews".
+
+#### SimpleX Links
+
+This option affects how the links to connect to other SimpleX users or to join groups are shown in the conversations. You can choose between:
+
+- _description_ (default): only the link description and server host name are shown. The link won't be opened in the browser.
+- _full link_: the full link is shown. The link will still not be opened in the browser.
+- _via browser_: the full link is shown, and it will be opened in the browser. In this case, if the link domain is different from simplex.chat, the link will be shown in red color, as it might be malicious.
+
+Read more about [SimpleX Links security](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#privacy-and-security-of-simplex-invitation-links).
+
+### Appearance
+
+This page allows configuring:
+
+- interface language
+- app icon
+- accent color
+
+### Database passphrase & export
+
+This page allows to change the database passphrase, export and import the database and configure the message retention period.
+
+Read more in [Managing Your Data](https://simplex.chat/docs/guide/managing-data.md) page.
+
+## Help & feedback
+
+This section has information on how to use the app and the links to connect to the team. Please use [Send questions and ideas](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion) to connect to us via the chat to ask any questions, make any suggestions and report any issues.
+
+## Support SimpleX Chat
+
+- contribute - the link to the information about how to contribute and to donate to the project.
+- rate the app - rate and review it on the App Store or Play Store - your feedback helps a lot.
+- star on GitHub - that also helps us grow very much.
+
+Thank you for your support!
+
+## Developer tools
+
+This page has options that normally are only needed for app developers and can be used to debug the app in case something is not working.
+
+### Chat console
+
+Here you can see and use console command with the chat core. None of this information is sent over the network, this is an internal communication between different parts of the app.
+
+Please be careful - some of the commands can disrupt app functioning, only use them if you know what you are doing or were instructed by the team.
+
+**Please note**: the log in console can contain what looks like errors. Unless you experience any issues in the app UI, these errors should not be considered as the app malfunction - they are likely to be normal and expected behavior.
+
+### Confirm database upgrades
+
+This option is off by default - the app database is migrated to the new version without any confirmations. Starting from v4.6.2 these migrations are reversible - you can rollback to the previous version(s) of the app (not earlier than v4.6.1). If you want to be asked a confirmation every time database is upgraded you may enable this option - this is not recommended, as it happens almost on every app update, and should not cause any concerns.
+
+### Show developer options
+
+This option currently enables [Transport isolation mode](#transport-isolation-beta) option and also enables showing database IDs in contacts, groups and group members to simplify debugging via console commands.
diff --git a/docs/guide/audio-video-calls.html b/docs/guide/audio-video-calls.html
index 9a4cdd6e3c..f29f1aa137 100644
--- a/docs/guide/audio-video-calls.html
+++ b/docs/guide/audio-video-calls.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/audio-video-calls.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/audio-video-calls.md b/docs/guide/audio-video-calls.md
new file mode 100644
index 0000000000..2dc3d92147
--- /dev/null
+++ b/docs/guide/audio-video-calls.md
@@ -0,0 +1,82 @@
+# Audio and Video Calls
+
+SimpleX Chat allows you to make end-to-end encrypted audio and video calls with your contacts via WebRTC. Note: Group calls are not supported at this time.
+
+## Making and accepting the calls
+
+### How to make an audio call
+
+1. Tap on a contact.
+2. Tap on the phone icon to the right of your contact's name at the top of the screen.
+
+### How to make a video call
+
+1. Tap on a contact.
+2. Tap on the three vertical dots on the top right-hand corner of the screen to access more options.
+3. Choose **Video call**.
+
+### Accepting the calls
+
+When there is an incoming call you have three options:
+
+- accept: to connect the call
+- reject: to reject the call, _without_ notifying the caller.
+- ignore: to temporarily dismiss the call, but in a way that it can be accepted later, if the caller is still waiting, via the **Accept call** message in the conversation with this contact.
+
+There is no time limit that the call invitation can remain active - as long as the caller is still waiting, you can accept the call any time later.
+
+The call can be accepted from the lock screen, both on Android (it needs to be enabled via options) and on iOS (by default, using native iOS call interface that can be disabled).
+
+### Calls on lock screen on Android
+
+SimpleX Chat shows an incoming call on your device's lock screen by default. However, you can change this behavior in the app settings menu.
+
+1. Open the app settings menu.
+2. Tap **Audio and Video calls**.
+3. On the **Calls on lock screen** drop-down list, choose from the following three options:
+   - Disable - the call will show as a notification.
+   - Show - the call will show on the lock screen, you need to unlock the device and the app to accept it.
+   - Accept - the call can be accepted and rejected directly from the lock screen, without opening the app.
+
+**Please note**: some Android systems/devices prohibit full screen views on lock screen - in this case the call will show as a usual notification.
+
+### Calls on lock screen on iOS
+
+<img src="../../blog/images/20230328-call1.png" width="288">
+
+By default, SimpleX Chat uses native iOS call interface, where allowed, to show incoming calls on the lock screen. You can disable it:
+
+1. Open the app settings menu.
+2. Tap **Audio and Video calls**.
+3. Toggle the **Use iOS call interface** switch off.
+
+**Please note**: iOS call interface allows accepting the calls without unlocking the device and the app. If this is undesirable, please disable it – the calls will show as notifications in this case.
+
+Read more in [this post](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.md#improved-audiovideo-calls).
+
+## Advanced call settings
+
+### WebRTC ICE servers
+
+<img src="../../blog/images/20220928-ice-servers.png" width="330">
+
+SimpleX Chat uses a preset relay server to hide your IP address from your contacts by default, but it can also observe the duration of your calls. If you don't want that, you can configure and use your self-hosted WebRTC relay servers instead for further control of your calls.
+
+1. Open the app settings menu.
+2. Tap **Audio and Video calls**.
+3. Tap **WebRTC ICE servers**.
+4. Toggle the **Configure ICE servers** switch on.
+5. Enter your ICE server addresses (one per line).
+6. Tap **Save**.
+
+**Please note**: unlike messaging relays (SMP servers), the configuration of WebRTC ICE servers is stored on the current device, not in the chat database. if you transfer the chat database to another device you need to update this configuration.
+
+### Always use relay
+
+Audio and video calls on SimpleX Chat are routed via a TURN relay server by default. Optionally you can disable this and use peer-to-peer (P2P) instead, when it is supported by your network. However, your IP address will be known to your contacts.
+
+1. Open the app settings menu.
+2. Tap **Audio and Video calls**.
+3. Toggle the **Always use relay** switch on to use a relay server or off for P2P.
+
+**Please note**: disabling this option allows P2P calls, but it does not prohibit the use of TURN relays – in case your network providers block P2P connections, the call will still use relays if the are available. To prohibit the use of relays you need to change WebRTC ICE server configuration to only include STUN servers, for example:
diff --git a/docs/guide/channel-webpage.html b/docs/guide/channel-webpage.html
index bd20214c6c..96db3af681 100644
--- a/docs/guide/channel-webpage.html
+++ b/docs/guide/channel-webpage.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/channel-webpage.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/channel-webpage.md b/docs/guide/channel-webpage.md
new file mode 100644
index 0000000000..64e9f544fe
--- /dev/null
+++ b/docs/guide/channel-webpage.md
@@ -0,0 +1,124 @@
+# Channel webpage
+
+A channel webpage shows a preview of your channel on the web: its name, description, recent messages and subscriber count. Visitors can see what the channel is about before they subscribe, and the page gives them a "Join" button along with links to download the app.
+
+You don't have to build the preview yourself. The chat relays that host your channel publish its content as a small file, and a ready-made script renders it on your page. All it takes is to copy the code the app generates and paste it into a web page you host.
+
+## What you need
+
+A channel webpage can be set up by the **owner** of the channel, as long as the channel is hosted on chat relays that support webpages. If they don't, the app shows "Used chat relays do not support webpages." and no code is generated.
+
+You'll also need somewhere to publish an HTML page. Your own site works, but any static hosting will do.
+
+## Step 1. Open the channel webpage settings
+
+Open the channel and tap its name at the top to open the channel information. Scroll down to **Advanced options** and tap **Channel webpage**. This button is only shown to channel owners.
+
+## Step 2. Allow embedding while you build the page
+
+Turn on **Allow anyone to embed** and tap **Save**.
+
+With this on, the relay serves your channel preview to any page, so you can build and test from wherever the page lives without it being tied to one domain yet. Leave the webpage URL empty for now; nothing is shown to your subscribers until you set it.
+
+## Step 3. Copy the code
+
+Under **Webpage code** you'll see a snippet like the one below. Tap **Copy code**.
+
+```html
+<div data-simplex-channel-preview
+  data-channel-link="https://smp15.simplex.im/c#Q-uRqD9tDixMf4Cd6UByeNN5nyIKkrgs4WaLlTnbjXs"
+  data-channel-id="kFXapqMZpdFGZFKXDibQPpDHV4aeA4x9dUk-PNKl1LA="
+  data-relay-domains="relay1.example.com"
+  data-app-download-buttons="on"
+  data-color-scheme="light"
+></div>
+<script src="https://simplex.chat/js/channel-preview.js"></script>
+```
+
+Everything specific to your channel is already in the code: its link, its ID, and the relay domains that serve the preview. There's no need to edit those values.
+
+## Step 4. Add the code to your page and test it
+
+Paste the snippet into the page you're going to publish. Here's a complete minimal page:
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>My Channel</title>
+  <style>
+    * { margin: 0; padding: 0; box-sizing: border-box; }
+    html, body { height: 100%; }
+    [data-simplex-channel-preview] { height: 100%; }
+  </style>
+</head>
+<body>
+  <div data-simplex-channel-preview
+    data-channel-link="https://smp15.simplex.im/c#Q-uRqD9tDixMf4Cd6UByeNN5nyIKkrgs4WaLlTnbjXs"
+    data-channel-id="kFXapqMZpdFGZFKXDibQPpDHV4aeA4x9dUk-PNKl1LA="
+    data-relay-domains="relay1.example.com"
+    data-app-download-buttons="on"
+  ></div>
+  <script src="https://simplex.chat/js/channel-preview.js"></script>
+</body>
+</html>
+```
+
+Publish the page and open it in a browser. The channel preview shows up in place of the `<div>`. Because embedding is still open, it loads no matter which address you test from, so you can adjust the page until it looks right.
+
+## Step 5. Set the webpage URL and lock it down
+
+Once the page works, go back to **Channel webpage** in the app:
+
+- Under **Enter webpage URL**, type the address where the page is published, for example `https://example.com/my-channel`.
+- Turn **Allow anyone to embed** off if you don't want other sites to be able to show your channel preview. Leave it on if you're happy for anyone to embed it.
+- Tap **Save**.
+
+The URL now appears as a link in your channel info that every subscriber can see. If you turned embedding off, the relay also restricts the preview to your own domain.
+
+## Customizing the preview
+
+You can add optional `data-*` attributes to the `<div>` to change how it looks. Only `data-channel-id` and `data-relay-domains` are required, and both are already in the generated code.
+
+| Attribute | Values | Default | What it does |
+| --- | --- | --- | --- |
+| `data-channel-id` | channel ID (from the app) | none | Required. Identifies the channel to load. |
+| `data-relay-domains` | comma-separated domains | none | Required. Relay domains that serve the preview, tried in order. |
+| `data-channel-link` | channel link | none | Enables the "Join" button and QR code. Recommended. |
+| `data-app-download-buttons` | `on`, `off` | `on` | Shows or hides the app download buttons. |
+| `data-color-scheme` | `light`, `dark`, `site` | `light` | Color theme. `site` follows your page's theme (it uses dark styling when a parent element has the `dark` CSS class). |
+| `data-light-background` | CSS color | `#ffffff` | Background color in light mode. |
+| `data-dark-background` | CSS color | `#000832` | Background color in dark mode. |
+| `data-relay-scheme` | `https`, `http` | `https` | Protocol used to load the preview from the relays. Leave it as `https`. |
+
+For example, here's a dark theme with a custom background and the download buttons hidden:
+
+```html
+<div data-simplex-channel-preview
+  data-channel-link="https://smp15.simplex.im/c#Q-uRqD9tDixMf4Cd6UByeNN5nyIKkrgs4WaLlTnbjXs"
+  data-channel-id="kFXapqMZpdFGZFKXDibQPpDHV4aeA4x9dUk-PNKl1LA="
+  data-relay-domains="relay1.example.com,relay2.example.com"
+  data-app-download-buttons="off"
+  data-color-scheme="dark"
+  data-dark-background="#001a4d"
+></div>
+<script src="https://simplex.chat/js/channel-preview.js"></script>
+```
+
+## Good to know
+
+The preview updates on its own. The relays republish channel content periodically, so the page picks up new messages without any change on your side. It's a read-only snapshot, so visitors can't post to it.
+
+Only what the channel already shows publicly is included: recent messages, member display names and avatars, reactions, and the subscriber count. Deleted and disappearing messages are never published.
+
+If your channel is served by more than one relay, all of them are listed in `data-relay-domains`. The script tries them in order, so the preview still loads when one relay is unavailable.
+
+## If something doesn't work
+
+If the preview area stays empty, check that the page is hosted on the same domain as the URL you set in Step 5, or turn **Allow anyone to embed** back on while you sort it out. The relay only lets that domain load the preview.
+
+If the app says "Used chat relays do not support webpages.", the relays hosting your channel don't support this feature yet, so no code can be generated.
+
+If there's no **Channel webpage** button, remember that it only appears for channel owners on channels hosted on relays.
diff --git a/docs/guide/chat-profiles.html b/docs/guide/chat-profiles.html
index 8c93e6954d..1896e2b9fd 100644
--- a/docs/guide/chat-profiles.html
+++ b/docs/guide/chat-profiles.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/chat-profiles.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/chat-profiles.md b/docs/guide/chat-profiles.md
new file mode 100644
index 0000000000..2587fa8c66
--- /dev/null
+++ b/docs/guide/chat-profiles.md
@@ -0,0 +1,96 @@
+# Your chat profiles
+
+## Creating additional chat profiles
+
+SimpleX Chat allows creating as many chat profiles as you like. Same as the first profile, they are only stored locally on your device.
+
+<img src="../../blog/images/20230204-profiles2.png" width="288">
+
+To create an additional SimpleX Chat profile:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Select "Your chat profiles".
+- Unlock option via fingerprint or PIN.
+- Tap on "+ Add profile”.
+- Create a new profile by inputting your display name and full name (optional).
+- Tap on "Create".
+
+## Hiding and muting chat profiles
+
+v4.6 added the ability to mute and to hide chat profiles.
+
+<img src="../../blog/images/20230328-hidden-profiles1.png" width="288">    <img src="../../blog/images/20230328-hidden-profiles2.png" width="288">    <img src="../../blog/images/20230328-hidden-profiles3.png" width="288">
+
+These actions are available via long-press (Android) or swipe (iOS) on the profile in the list.
+
+To unhide hidden profiles, enter the full password in the search bar.
+
+## Switching between profiles
+
+<img src="../../blog/images/20230204-profiles1.png" width="288">
+
+- Tap on your user profile image in the upper right-hand of the screen.
+- Select which profile you want to use.
+
+You can also switch profile via Your chat profiles in the settings.
+
+## Incognito mode
+
+<img src="../../blog/images/20220901-incognito1.png" width="330"> <img src="../../blog/images/20220901-incognito2.png" width="330"> <img src="../../blog/images/20220901-incognito3.png" width="330">
+
+This feature is unique to SimpleX Chat – it is independent from chat profiles.
+
+When "Incognito Mode” is turned on, your currently chosen profile name and image are hidden from your new contacts. It allows anonymous connections with other people without any shared data – when you make new connections or join groups via a link a new random profile name will be generated for each connection.
+
+To toggle the incognito mode on/off:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Turn on/off incognito mode by tapping on the switch on "Incognito".
+
+Please read more in [this post](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.md#incognito-mode).
+
+## Edit your profile
+
+To edit your profile:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Select your profile.
+- Tap on "Edit".
+- Input your desired profile name and/or update your full name.
+- You can also set and change profile image.
+- Tap on "Save and notify contacts".
+
+## Move your chat profiles to another device
+
+SimpleX Chat stores all user data only on client devices using a portable encrypted database format that can be exported and transferred to any supported device.
+
+To export your SimpleX Chat data:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Select "Database passphrase & export".
+- Stop chat by toggling "Chat is running" (tap "Stop” in the confirmation dialog).
+- Confirm it with fingerprint or PIN, in case you have [SimpleX Lock](https://simplex.chat/docs/guide/app-settings.md#simplex-lock) enabled.
+- If you didn't set it before, [set a passphrase](https://simplex.chat/docs/guide/managing-data.md#database-passphrase) in "Database passphrase". Initially, the database is encrypted with a random passphrase that is stored in KeyChain (iOS) or with KeyStore (Android).
+- Tap on "Export database" - it won't allow exporting unless you have set a passphrase.
+- Save the file on your device or share it via any available option.
+
+To import your SimpleX Chat data in the app on another device:
+
+- Transfer the database file to the new device.
+- Install SimpleX Chat app.
+- Create chat profile with any name by following the steps in [Create your first chat profile](#create-yout-first-chat-profile) – you will replace it soon.
+- Open the app settings
+- Select "Database passphrase & export".
+- Stop chat by tapping the switch on "Chat is running".
+- Tap "Import database".
+- Select the .zip file of the exported chat data.
+- Tap "Import” in the confirmation dialog.
+- Start chat via toggle or close and start the app – you will be prompted to enter the passphrase for your chat database.
+
+**Please note**:
+
+1. Currently you cannot move some of the profiles, only the whole database containing all profiles can be moved.
+
+2. You must NOT use the exported database on more than one device at a time, as it may disrupt some of the connections. You also must always use the latest version of the chat database - using the old one is also likely to disrupt your connections.
+
+3. There is no way to recover lost passphrase - make sure to store it securely.
diff --git a/docs/guide/making-connections.html b/docs/guide/making-connections.html
index 67595821e0..d60595c157 100644
--- a/docs/guide/making-connections.html
+++ b/docs/guide/making-connections.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/making-connections.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/making-connections.md b/docs/guide/making-connections.md
new file mode 100644
index 0000000000..799183bde9
--- /dev/null
+++ b/docs/guide/making-connections.md
@@ -0,0 +1,81 @@
+# Connect to somebody in the chat
+
+_Work in progress_
+
+Because you have no identifier on the SimpleX platform, nobody can contact you unless you share a one-time or temporary user address, such as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+Private Connection — connect using an invitation link or QR code via video or in-person.
+
+Group Chat — Users have the option to create a secret group, share their contact link [which can be deleted later on], or generate a one-time invitation link.
+
+## Your SimpleX contact address
+
+You can [create an optional long term address](https://simplex.chat/docs/guide/app-settings.md#your-simplex-contact-address) for other people to connect with you. Unlike 1-time invitation links, these addresses can be used many times, that makes them good to share online, e.g. on social media platforms, or in email signatures. That helps more people discover SimpleX Chat, so please do it!
+
+When people connect to you via this address, you will receive a connection request that you can accept or reject. You can configure an automatic acceptance of connection request and an automatic welcome message that will be sent to the new contacts. You can also share this address as part of your SimpleX profile, so group members can connect to you, and your contacts can share it with others - if this is something that you want.
+
+If you start receiving too many requests via this address it is always safe to remove it – all the connections you created via this address will remain active, as this address is not used to deliver the messages.
+
+### Comparison of 1-time invitation links and SimpleX Contact addresses
+
+<table>
+  <tr>
+    <th></th>
+    <th>1-time invitation link</th>
+    <th>SimpleX contact address</th>
+  </tr>
+  <tr>
+    <td>Can be used many times?</td>
+    <td>No</td>
+    <td>Yes</td>
+  </tr>
+  <tr>
+    <td>Can be included in user profile?</td>
+    <td>No, as it can only be used once.</td>
+    <td>Yes, to allow group members to connect directly, and your contacts to pass it on to their contacts.</td>
+  </tr>
+  <tr>
+    <td>When to use it?</td>
+    <td>With somebody you know, via another communication channel or QR code (in person or during a video call)</td>
+    <td>Where many people can see and connect via it, e.g. in email signature, website, social media or group chat.</td>
+  </tr>
+  <tr>
+    <td>Security</td>
+    <td>More secure, as can only be used once, and the initial connection request (including profile) is encrypted with double ratchet.</td>
+    <td>Initial connection request is also e2e encrypted, but without double ratchet (it is initialized when request is accepted).</td>
+  </tr>
+  <tr>
+    <td>Identification</td>
+    <td>Both sides know who they connect to, as they know with whom and by who the link was shared. You can attach alias to this invitation as soon as you share it or use it, to identify the other person when connection is established.</td>
+    <td>Only the person using the address knows who they connect to, via the channel where they found the address (email, social media, etc.). The address owner can only see the user profile of the request, and has no proof of identity from the person sending the request<sup>*</sup>.</td>
+  </tr>
+  <tr>
+    <td>Advantages over other platforms</td>
+    <td>There is no direct analogy, other platforms don’t offer one-time invitations without any fixed part identifying the user.</td>
+    <td>Unlike addresses in other platforms, SimpleX addresses are not used to deliver the messages — only the initial connection requests.<br>It means that removing this address will not break the contacts made via it (like changing an email address would), it would only prevent new connections, which makes it a good solution against spam and abuse.</td>
+  </tr>
+  <tr>
+    <td>Vulnerability to attacks</td>
+    <td>Until the connection is established, anybody who intercepts this link can connect to it, so it has to be verified with the original contact that the connection succeeded.</td>
+    <td>These addresses are vulnerable to connection request spam. Unlike other platforms, you can delete or change the address, without losing any contacts (see above).</td>
+  </tr>
+  <tr>
+    <td>Passive attacks on connection links</td>
+    <td colspan="2">Both types of links are not vulnerable if simply observed — they only contain public keys. So they can be safely shared via insecure or public channels, as long as you can confirm that you connected to the intended person.</td>
+  </tr>
+  <tr>
+    <td>Active attacks on connection links</td>
+    <td colspan="2">If the link is substituted via the attack on the channel used to share it, the connection security can be compromised, and the original messages monitored (man-in-the-middle attack). If it is a real risk then security code should be verified to mitigate it - doing so proves<sup>**</sup> that the link and keys were not substituted, and that the end-to-end encryption is secure.</td>
+  </tr>
+</table>
+
+<sup>*</sup> Adding optional verified identities that we plan in the future will change it — the address owner will have an option to request identity verification before accepting the connection.
+
+<sup>**</sup> Connection security code is the cryptographic hash (SHA256) of combined public keys of both sides — there are 2<sup>256</sup> possible security codes (1 with 77 zeros – about [1000 times smaller](https://www.wolframalpha.com/input?i=2%5E256) than the estimated number of atoms in the visible universe).
+
+## Conversation preferences
+
+Tap on one of your conversations to open conversation preferences.
+Here you can choose whether you wish to allow disappearing messages, deleting messages for everyone and voice messages.
diff --git a/docs/guide/managing-data.html b/docs/guide/managing-data.html
index e68c352a3c..79a77b0371 100644
--- a/docs/guide/managing-data.html
+++ b/docs/guide/managing-data.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/managing-data.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/managing-data.md b/docs/guide/managing-data.md
new file mode 100644
index 0000000000..63279f978a
--- /dev/null
+++ b/docs/guide/managing-data.md
@@ -0,0 +1,42 @@
+# Managing Your Data
+
+## Automatic message deletion
+
+Here you can choose to delete messages from your local chat database after a set period of time.
+
+**Please note**: This option does not delete messages for other users, only for you. This option is set independently for each chat profile.
+
+## Chat Database
+
+To open your chat database settings:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Tap on "Database passphrase & export" button.
+
+### Database passphrase
+
+<img src="../../blog/images/20220928-passphrase.png" width="330">
+
+By default, database passphrase is random, you have to set it manually to be able to export it.
+
+### App data backup
+
+Here you can allow the system to back up app data, wherever it is configured. A database passphrase must be set to use this.
+
+### Export database
+
+Here you can export the chat database to a file.
+
+### Import database
+
+Here you can import the chat database from a file.
+
+### Delete database
+
+Here you can delete your chat database. WARNING: Results in a loss of all your SimpleX Chat data! Unless you have just exported the chat database.
+
+## Delete files and media
+
+<img src="../../blog/images/20220928-files-media.png" width="330">
+
+You can delete all sent and received files and media stored in the app via this option, without deleting the messages.
diff --git a/docs/guide/privacy-security.html b/docs/guide/privacy-security.html
index 259d5cab2f..2787d5ab9c 100644
--- a/docs/guide/privacy-security.html
+++ b/docs/guide/privacy-security.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/privacy-security.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/privacy-security.md b/docs/guide/privacy-security.md
new file mode 100644
index 0000000000..1611e58006
--- /dev/null
+++ b/docs/guide/privacy-security.md
@@ -0,0 +1,57 @@
+# Privacy and Security
+
+SimpleX Chat default configuration aims to balance privacy, security and convenience. You may want to change the default options.
+
+This page lists all the features and options that affect privacy and security.
+
+## Privacy and Security settings
+
+These settings are available in the [Privacy & Security settings](https://simplex.chat/docs/guide/app-settings.md#privacy-and-security).
+
+## Security code verification
+
+<img src="../../blog/images/20230103-verification.png" width="288">
+
+While SimpleX Chat always establishes connection via link passed via an independent channel, so it is already more protected than other apps, there are scenarios when the invitation links can be substituted in transit (MITM attack). To protect against such attacks, you should verify the security code with your contacts:
+
+- open the conversation with the contact
+- tap the contact name on top of the conversation
+- tap "Verify security code"
+- ask your contact to do the same
+- the connection is secure if you and your contact have the same security code
+
+This can be validated by one of the following:
+
+- one of you can scan the security code from their device, if the codes match the contact will be marked as verified on the device that scanned the code.
+- simply tap mark verified if you trust the confirmation from your contact that the code is verified.
+- you can also read the contact over the voice call.
+
+Read more in [this post](https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.md#connection-security-verification)
+
+## Database passphrase
+
+When installed, the app generates a random passphrase for the chat database and stores it securely in KeyChain (iOS) or using KeyStore (Android, TPM module is used when available). You can set your own passphrase and also remove it from the device, in which case you will need to enter it every time you start the app, and notifications may be limited, in the [Database passphrase & export](https://simplex.chat/docs/guide/managing-data.md#database-passphrase) settings.
+
+## Incognito mode
+
+This feature generates a random profile name for each new contact. Read more in [Incognito mode](https://simplex.chat/docs/guide/app-settings.md#incognito).
+
+## Hidden profiles
+
+This feature allows to hide some of your chat profiles with the password. Read more in [Hiding and muting chat profiles](https://simplex.chat/docs/guide/chat-profiles.md#hiding-and-muting-chat-profiles).
+
+## Network settings
+
+[Transport isolation (BETA)](https://simplex.chat/docs/guide/app-settings.md#transport-isolation-beta) allows to isolate you traffic with each contact in a different TCP connection (and Tor circuit).
+
+## Using Tor
+
+<img src="../../blog/images/20220808-tor1.png" width="330">   <img src="../../blog/images/20220808-tor2.png" width="330">
+
+To connect to SMP relays (messaging servers) via Tor you need to install Orbot app.
+
+Android: use Orbot app as SOCKS proxy on port 9050 (default) and enable [Use SOCKS proxy](https://simplex.chat/docs/guide/app-settings.md#use-socks-proxy-android-only).
+
+iOS: use Orbot app as VPN provider and enable VPN.
+
+You can also change which server addresses are used with [Use .onion hosts option](https://simplex.chat/docs/guide/app-settings.md#use-onion-hosts).
diff --git a/docs/guide/readme.html b/docs/guide/readme.html
index db29566ef7..121c67f248 100644
--- a/docs/guide/readme.html
+++ b/docs/guide/readme.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/readme.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/readme.md b/docs/guide/readme.md
new file mode 100644
index 0000000000..882a158fa4
--- /dev/null
+++ b/docs/guide/readme.md
@@ -0,0 +1,81 @@
+# SimpleX Chat User Guide
+
+The first messaging platform that has no user identifiers of any kind — 100% private by design.
+
+## Contents
+
+- [Quick start](#quick-start) - scroll down this page
+- [Sending messages](https://simplex.chat/docs/guide/send-messages.md)
+- [Secret groups](https://simplex.chat/docs/guide/secret-groups.md)
+- [Channel webpage](https://simplex.chat/docs/guide/channel-webpage.md)
+- [Chat profiles](https://simplex.chat/docs/guide/chat-profiles.md)
+- [Registering a SimpleX name](https://simplex.chat/docs/guide/register-simplex-name.md)
+- [Managing data](https://simplex.chat/docs/guide/managing-data.md)
+- [Audio & video calls](https://simplex.chat/docs/guide/audio-video-calls.md)
+- [Privacy & security](https://simplex.chat/docs/guide/privacy-security.md)
+- [App settings](https://simplex.chat/docs/guide/app-settings.md)
+
+## Quick start
+
+### Create your first chat profile
+
+After downloading SimpleX Chat via the links at https://simplex.chat:
+
+- Open the app.
+- Create a new profile by inputting your display name and full name (optional).
+- Tap on "Create".
+
+This profile is local to the device, it is not stored anywhere else
+
+### Choose notifications mode
+
+After you have created the chat profile the app will ask you to choose notifications mode.
+
+<img src="../../blog/images/20220711-notifications.png" width="330">
+
+Please read their description, as on iOS it is trade-off between convenience and privacy, with instant notifications sharing more meta-data with the servers, and on Android it is a trade-off between notification delays and battery life.
+
+You can read more about [the differences between notifications work on Android and iOS](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md).
+
+### Connect to developers
+
+When you just start using the app, you can tap "chat with the developers" to ask any questions or just to test the app - feel free to send any test messages.
+
+This button will disappear once you make the first connection. To connect to the developers later:
+
+- [Open the app settings](https://simplex.chat/docs/guide/app-settings.md#opening-the-app-settings).
+- Tap on "Send questions and ideas".
+
+### Join some user groups
+
+There are links to join several [user groups](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md) on our GitHub page - join them to ask any questions and discuss ideas.
+
+You can also find some other user-managed groups via online search.
+
+To join a group via a link:
+
+- Get a link to a SimpleX user group, which you can get from your existing SimpleX conversations or by finding it online.
+- Tap on a button in the lower right-hand of the screen.
+- Tap on "Connect via link / QR code" button.
+
+### Connect to friends
+
+- Tell your friends to download SimpleX Chat app via one of the links here: https://simplex.chat
+- Create a one-time link for each of you friends by tapping new chat button (Android: a floating pencil button in the bottom right corner, iOS: a pencil button in the top right corner)
+- Tap _Create one-time invitation link_.
+- Share each link with a different friend, or alternatively let them scan a QR code.
+- You can optionally assign a different alias to each link, to know when they connect who is who, if they use incognito mode, for example.
+- To use your link or QR code, tell your friends to tap new chat button and then tap on "Connect via link / QR code".
+- They can either scan QR code or paste the link. If they opened the link in the browser, they need to tap "Open in mobile app" button on the page.
+
+Watch the video on [the website](https://simplex.chat) that shows how it works.
+
+You can also create a [long-term contact address](https://simplex.chat/docs/guide/app-settings.md#your-simplex-contact-address).
+
+### Explore the app
+
+Most app settings are shared for all profiles, but some settings are specific to chat profile.
+
+Read more in [App settings](https://simplex.chat/docs/guide/app-settings.md) page.
+
+Many conversation actions are available via long-press or swipe – try them!
diff --git a/docs/guide/register-simplex-name.html b/docs/guide/register-simplex-name.html
index 945cfc8522..1c23104838 100644
--- a/docs/guide/register-simplex-name.html
+++ b/docs/guide/register-simplex-name.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/register-simplex-name.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/register-simplex-name.md b/docs/guide/register-simplex-name.md
new file mode 100644
index 0000000000..ce9ae89ad1
--- /dev/null
+++ b/docs/guide/register-simplex-name.md
@@ -0,0 +1,119 @@
+# Registering a SimpleX name
+
+A SimpleX name lets people reach you by typing a short `@name` instead of pasting
+a long link. You register the name on a website and add your SimpleX link to it,
+then claim the name in the app, to connect it with your SimpleX address or
+channel name.
+
+> Names currently run on a testing network. The registration page is
+> [testing-names.simplex.chat](https://testing-names.simplex.chat) and names end
+> in `.testing`. The steps stay the same when the main names launch.
+
+## What you need
+
+- A crypto wallet such as MetaMask.
+- The SimpleX app.
+- A link for the name to open: your **contact address** (for one-to-one chats),
+  your **channel link** (to join a channel), or both.
+
+## How it works
+
+Setting up a name takes two parts. On the website you register the name and add
+your link, so people can find your link by name. In the app you set the same name
+on your profile - to prevent any other names from opening your profile or channel.
+
+![Steps to register a SimpleX name](diagrams/simplex-name-steps.svg)
+
+## Step 1. Create a wallet
+
+Install MetaMask (browser extension or mobile app) and create a wallet. Write
+down your recovery phrase somewhere safe and offline, as anyone with that phrase
+controls your names.
+
+On the testing network you need a small amount of test ETH to pay network fees.
+
+## Step 2. Register the name and add your link
+
+Open the registration page and tap **Connect** to link your wallet. Type the
+name you want in **Search for a name** and open it. Choose how many years to
+register for, then tap **Next**. Names are currently 6 characters or more, and
+some names are reserved.
+
+![Register your name and choose the registration period](images/register-name.png)
+
+On **Create your profile**, paste your SimpleX link into the matching field:
+
+![Create your profile](images/create-your-profile.png)
+
+- **SimpleX contact** for one-to-one chats. Copy your address from the app
+  (**Create SimpleX address**) and paste it here. People reach it with `@name`.
+- **SimpleX channel** for a channel. Copy your **Channel link** and paste it here.
+  People join it with `#name`.
+- **Advanced usage:** fill both to use one name for your chat (`@name`) and your
+  channel (`#name`).
+
+Then tap **Next**.
+
+Finally, tap **Begin** and complete the three steps the site shows:
+
+> Before we start. Registering your name takes three steps:
+> 1. Complete a transaction to begin the timer.
+> 2. Wait 60 seconds for the timer to complete.
+> 3. Complete a second transaction to secure your name.
+
+These two transactions protect the name you are registering. The first records
+only a secret code for the name, not the name itself, so nobody watching the
+blockchain can see which name you want. The wait lets that first transaction
+settle, and the second transaction then reveals and claims the name. Without this
+two-step process, someone could see your registration in progress and grab the
+name before you.
+
+![The three steps to secure your name](images/before-we-start.png)
+
+## Step 3. Check what the app sees
+
+Copy your `#name.testing` (or `@name.testing`). Paste the name into the search bar, or simply type it.
+
+The app reports that the name is registered but not yet added to your profile:
+
+> Unconfirmed name. The SimpleX name is registered, but not added to profile.
+> Please add it to your address or channel profile, if you are the owner.
+
+This is expected, and confirms the name points at your link. The next step
+finishes the setup.
+
+## Step 4. Claim the name in the app
+
+Set the name on the same profile the record points at.
+
+- For your **contact address**, open your SimpleX address, tap **Get SimpleX
+  name**, enter the name, and save.
+- For your **channel**, open the channel information, tap **Get SimpleX name** (under
+  **Channel link**), enter the name, and save.
+
+This proves to people who connect to you that `#name.testing` (or `@name.testing`) is your name.
+
+## Step 5. Connect by name
+
+On another device, copy `#name.testing` (or `@name.testing`). Paste the name into the search bar, or simply type it. This time the app connects, and the name
+shows a check mark next to it.
+
+You can paste the name in your own device too - the app will warn you that it is your own name.
+
+Anyone can now reach you by name, and their app confirms it is really you.
+
+## If something doesn't work
+
+| Message | Meaning | Fix |
+|---|---|---|
+| Unconfirmed name | The name points at a link, but the link's profile does not claim the name yet. | Do step 4: set the name on the profile it points at. |
+| Name not found | No name is registered. | Check the spelling, or register it (step 2). |
+| No valid link | The name has no contact or channel link. | Add a link to the name on the website, on its **Records** tab. |
+| Error saving name | You tried to claim a name that has no matching link on the website. | Add your contact address or channel link to the name, then set the name again. |
+| None of your servers are set to resolve SimpleX names | No server in the app is set to resolve names. | In server settings, turn on **To resolve names** for a server. |
+
+## See also
+
+- [Making connections](https://simplex.chat/docs/guide/making-connections.md)
+- [Chat profiles](https://simplex.chat/docs/guide/chat-profiles.md)
+- [Channel webpage](https://simplex.chat/docs/guide/channel-webpage.md)
diff --git a/docs/guide/secret-groups.html b/docs/guide/secret-groups.html
index 28543e05d1..fa2ac36294 100644
--- a/docs/guide/secret-groups.html
+++ b/docs/guide/secret-groups.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/secret-groups.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/secret-groups.md b/docs/guide/secret-groups.md
new file mode 100644
index 0000000000..11be81367d
--- /dev/null
+++ b/docs/guide/secret-groups.md
@@ -0,0 +1,66 @@
+# Secret groups
+
+Secret groups are anonymous and private, they are designed to be hard to track by outsiders. Every message and file gets sent separately to every member in the group, which makes secret groups only fit for smaller groups.
+
+## Creating a group
+
+<img src="../../blog/images/20220808-group1.png" width="330"> <img src="../../blog/images/20220808-group2.png" width="330"> <img src="../../blog/images/20220808-group3.png" width="330">
+
+- Tap on a button in the lower right-hand of the screen.
+- Tap on "Create secret group".
+- Enter group display name.
+- Tap on "Create".
+
+## Group preferences
+
+Here you can choose whether you want to allow disappearing messages, direct messages, deleting for everyone and voice messages.
+
+## Adding members
+
+- Open a group.
+- Tap on + button in the upper right-hand of the screen.
+- Select contacts you wish to invite.
+- Tap on "Invite to group".
+
+## Joining a group
+
+<img src="../../blog/images/20220723-group-invite.png" width="330">
+
+When you receive the invitation to join the group you can accept it both from the conversation with your contact and from the list of conversations.
+
+## Leaving a group
+
+<img src="../../blog/images/20220723-group-leave.png" width="330">
+
+Tap and hold (Android) or swipe (iOS) the group in the list of the conversations to leave the group.
+
+You can also leave the group from the group page:
+
+- Open a group conversation.
+- Tap group name on top.
+- Scroll to the bottom and tap "Leave group".
+
+## Member permissions
+
+Open a group and tap on group's name to view members list, there you can tap on a member and change their role.
+
+- Observer: can only read messages (and delete or mark deleted the messages they sent before their role was changed).
+- Member: can send messages and delete own messages.
+- Admin: Same as member, but can delete the messages of others and remove members from the group.
+- Owner: Same as admin, but can change group preferences.
+
+## Link to join group
+
+<img src="../../blog/images/20221108-group1.png" width="288">    <img src="../../blog/images/20221108-group2.png" width="288">
+
+If you are a group owner or admin, you can create a link that can be used by anyone to join the group, making a group more public.
+
+- Open a group conversation.
+- Tap group name.
+- Tap on "Create group link.
+
+Once the link is created, you can also change the role assigned to members when they join.
+
+## Welcome message
+
+If you are a group owner you can create a welcome message that will be shown to all new members joining group.
diff --git a/docs/guide/send-messages.html b/docs/guide/send-messages.html
index f47698b149..df605cea82 100644
--- a/docs/guide/send-messages.html
+++ b/docs/guide/send-messages.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/guide/send-messages.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/guide/send-messages.md b/docs/guide/send-messages.md
new file mode 100644
index 0000000000..3522ad2641
--- /dev/null
+++ b/docs/guide/send-messages.md
@@ -0,0 +1,99 @@
+# Sending, editing and deleting messages
+
+Sending text messages on SimpleX Chat is pretty straightforward, tap on your contact and then tap on text area, type in your message and tap on "Send" button.
+
+You need to open a conversation to send messages.
+
+## Sending messages
+
+### Sending text messages
+
+You can send, edit and quote messages in a conversation.
+
+To send, simply type in the message in the entry box and tap "Send".
+
+To edit or quote a message, tap and hold the message and choose the action.
+
+### Sending images and files
+
+- Tap 📎 (paperclip) button on the left of the message entry box.
+- Choose between "Use Camera", "From Gallery" and "Choose file".
+- Once you have chosen what you wish to send, tap on "Send" button.
+
+On iOS you can also paste images from the clipboard.
+
+### Sending voice messages
+
+<img src="../../blog/images/20221206-voice.png" width="288">
+
+- Tap 🎤 (microphone) button on the right of the message entry box.
+- Allow SimpleX Chat to record the voice if prompted. You will have to tap on the microphone button once again if this happens.
+- Speak, once you've finished the recording, tap on the square stop icon on the right.
+- You may listen to the recording before sending it, and re-record if necessary.
+- Tap on "Send" button to send the recorded voice message.
+
+You can also tap and hold the microphone button to record a voice message. In this case the recording will stop once you release the button. You still need to tap "Send" to send the message.
+
+**Please note**: if the microphone button is gray, that means voice messages are disabled in this conversation. Ask your contact or group owner to enable them (they are enabled by default).
+
+### How to use disappearing messages
+
+<img src="../../blog/images/20230103-disappearing2.png" width="288">    <img src="../../blog/images/20230103-disappearing1.png" width="288">
+
+- Tap on name of the conversation.
+- Toggle the slider next to "Disappearing messages".
+- Choose how long until messages are deleted after being sent in "Delete after".
+
+**Please note**: Your contact must also enable disappearing messages. In a group, only group owner can enable disappearing messages.
+
+### Sending "live" messages
+
+<img src="../../blog/images/20230103-live.png" width="288">
+
+You can use "live" messages for your recipients to see the messages as you type them, without having to tap "Send" button until it's completed. It can be useful in these scenarios:
+
+1. Real-time conversation, like talking in person or in a discussion club. You can retract what you wrote, but your recipients would see it. Also people don’t need to guess what you’re typing. This allows to avoid interrupting the flow of conversation and still send longer messages.
+2. An activist doing live reporting when there is a risk to lose the phone or connection at any moment. This feature allows to send as much as possible, up to the last word, without having to send only very short messages.
+
+To send a "live" message:
+
+- Tap ⚡️ (lightning) button on the right of the message entry box.
+- When you do it first time, you would see and alert explaining the feature. Tap "OK", and tap it again.
+- Now you can start typing the messages, the app will be periodically sending the updates to your recipients, as you type (every few seconds, and only complete words).
+
+### Sending stickers and animated messages
+
+<img src="../../blog/images/20230103-stickers1.png" width="288">    <img src="../../blog/images/20230103-stickers2.png" width="303">
+
+While there are no stickers and GIFs in the app itself, you can send them using third-party (such as [GIPHY](https://apps.apple.com/us/app/giphy-the-gif-search-engine/id974748812) on iOS) or native (Android 13+) keyboards.
+
+### Message drafts
+
+<img src="../../blog/images/20230204-draft1.png" width="288">    <img src="../../blog/images/20230204-draft2.png" width="288">
+
+Messages are kept in the chat until they are sent, even if you leave the chat.
+
+For privacy and simplicity, we decided to allow only one message draft and keep it only until the app is stopped.
+
+Read more in [this post](https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.md#message-draft).
+
+## Deleting messages
+
+<img src="../../blog/images/20221206-deleted1.png" width="288">    <img src="../../blog/images/20221206-deleted2.png" width="288">
+
+To delete a message, tap and hold the message and choose "Delete".
+
+If you sent this message yourself within the last 24 hours, you will be offered two options:
+
+- `delete for everyone` - this will either mark the message as deleted for you and the recipient(s) (this is the default) or fully delete the message on your and recipients' devices (if you have enabled "Delete for everyone" in the conversation preferences)
+- `delete for me` - this will delete the message only locally.
+
+Please read about [reasons for not allowing full deletion by default](https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.md#irreversible-message-deletion). TL;DR: data sovereignty.
+
+## Moderating messages in the groups
+
+Group admins can delete member messages that are inappropriate for the groups.
+
+To remove a message of another member, tap and hold the message and choose "Moderate".
+
+Please read about [group moderation](https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.md#community-moderation).
diff --git a/docs/lang/cs/android.html b/docs/lang/cs/android.html
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/cs/cli.html b/docs/lang/cs/cli.html
index bd010c2aaf..f4eabe112a 100644
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/cs/contributing.html b/docs/lang/cs/contributing.html
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
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diff --git a/docs/lang/cs/server.html b/docs/lang/cs/server.html
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+        
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+
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         <link href="/css/tailwind.css" rel="stylesheet"/>
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diff --git a/docs/lang/cs/simplex.html b/docs/lang/cs/simplex.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
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+
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         <link href="/css/tailwind.css" rel="stylesheet"/>
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diff --git a/docs/lang/cs/translations.html b/docs/lang/cs/translations.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/cli.html b/docs/lang/fr/cli.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/contributing.html b/docs/lang/fr/contributing.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/server.html b/docs/lang/fr/server.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/simplex.html b/docs/lang/fr/simplex.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/translations.html b/docs/lang/fr/translations.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/fr/webrtc.html b/docs/lang/fr/webrtc.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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+        
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+<link rel="describedby" href="/llms.txt"/>
+
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         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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+        
+
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+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
+
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+
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         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/pl/simplex.html b/docs/lang/pl/simplex.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/lang/pl/translations.html b/docs/lang/pl/translations.html
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
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+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/protocol/badges-overview.html b/docs/protocol/badges-overview.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/protocol/badges-overview.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
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diff --git a/docs/protocol/badges-overview.md b/docs/protocol/badges-overview.md
new file mode 100644
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@@ -0,0 +1,307 @@
+Revision 1, 2026-09-18
+
+# SimpleX Supporter Badges
+
+## Table of contents
+
+- [Introduction](#introduction)
+  - [What is a badge](#what-is-a-badge)
+  - [What a badge grants](#what-a-badge-grants)
+  - [What a badge discloses](#what-a-badge-discloses)
+  - [Comparison with Signal badges](#comparison-with-signal-badges)
+  - [Non-goals](#non-goals)
+- [Architecture](#architecture)
+  - [Participants](#participants)
+  - [Service requests](#service-requests)
+  - [Buying and redeeming](#buying-and-redeeming)
+  - [Monthly issuance](#monthly-issuance)
+  - [Presentation](#presentation)
+  - [Servers](#servers)
+- [Cryptographic primitives](#cryptographic-primitives)
+- [Security](#security)
+  - [Design objectives](#design-objectives)
+  - [Threat model](#threat-model)
+- [Future work](#future-work)
+
+
+## Introduction
+
+The goal is for SimpleX Chat to be partly funded by its users, who buy supporter badges. A badge is shown on the profile of the person who bought it, and it raises the limits that other users and servers apply to that person's files. This document describes what a badge is, what it grants, how it is issued and presented, and what it discloses about the holder.
+
+A badge is stored in the user's profile on the device, and it is presented as proofs that cannot be linked to each other or to the purchase. The SimpleX network has no accounts, and a paid feature must not introduce one: in other messengers a paid feature is attached to an account, and the operator sees in one record who paid and what they did with the feature.
+
+### What is a badge
+
+A badge is a credential issued by the badge service, a bot operated by SimpleX Chat. The credential is a [BBS signature](https://datatracker.ietf.org/doc/draft-irtf-cfrg-bbs-signatures/) over four values: a master key generated by the app; the expiry date; the badge type, currently `supporter` or `legend`; and a reserved field that is currently empty.
+
+The holder of a BBS signature can prove that the issuer signed certain values, disclose some of those values, and keep the other values and the signature itself secret. The credential itself is therefore not sent to anyone. When the badge is to be shown or used, the app generates a proof that discloses the badge type, the expiry date and the reserved field, names the issuer key by its index, and hides the master key and the signature. Two proofs from the same credential cannot be linked to each other, by the issuer or by anyone else. Each proof is generated for one context, whether a conversation, a file or a session with a server, and is not accepted in any other.
+
+The transport protocols of the network call the same credential an entitlement: a name, an expiry and an extra string, disclosed in a proof. The chat application puts the badge type into the name, so a server that verifies an entitlement and a contact who sees a badge are looking at different zero-knowledge proofs of the same credential.
+
+### What a badge grants
+
+- A badge is shown on the profile to contacts, to the members of groups, and to the subscribers of channels.
+- A badge allows larger files. The default limit is 1GB; a supporter can send files up to 2GB, and a legend up to 5GB. The limit is applied by the recipient, whose app verifies the sender's proof before it accepts a file above the default size.
+- A badge extends the storage of files on servers. An XFTP server stores a file for 48 hours by default. It may be configured to store files for longer when they are uploaded by the holder of a badge of a given type; the example values in the server configuration file are 7 and 21 days for supporter and legend badge holders, respectively.
+
+Two other uses are planned and described under [Future work](#future-work):
+
+- A backup will be a link whose content the app replaces each time it makes a new backup, so that the same link restores the latest state. A badge will raise the size of the backup and the time it is stored, and the storage time is then the period the app can remain offline before the backup is lost.
+- Servers that verify the proof will apply higher rate limits when creating messaging queues, file chunks and notification tokens.
+
+### What a badge discloses
+
+The badge service holds the purchase key, the number of months bought, and the payment record of the purchase. A card payment is linked to the purchase, as in any other service; a user who wants the payment itself to be private may pay with cryptocurrency. In either case the record is held by the service alone, and the service does not learn where the badge is later shown or used, because a zero-knowledge proof contains nothing that refers back to the credential or the purchase.
+
+A party that verifies a proof learns the badge type and the expiry date. Since all credentials expiring in the same week have the same expiry date, these two values place the holder among the supporters whose badges expire that week.
+
+### Comparison with Signal badges
+
+Signal sells donation badges using [receipt credentials](https://eprint.iacr.org/2019/1416.pdf). The client obtains a credential against a payment without revealing its account, and then presents the credential once to the account server, which records its serial number, level and expiry against the account and attaches the badge to the account. The payment is not linked to the account cryptographically. The same mechanism is used for Signal's paid backups.
+
+The differences follow from Signal having accounts and SimpleX not having them.
+
+In Signal:
+
+- The server holds the list of accounts that have badges.
+- The credential can be verified only by the server that issued it.
+- The credential is presented once, after which the badge is a property of the account.
+- The client requests the credential and redeems it in a single sequence of jobs without delay, so the server can match the request made under the payment with the redemption made under the account by their times and by network address.
+- The expiry of a credential is rounded up to the next day.
+
+In SimpleX:
+
+- A server verifies a proof for one session and cannot link that session to any other.
+- A credential can be verified against the issuer's public key by contacts, channel relays and independently operated servers.
+- A credential is presented every time the badge is shown or used, with a new proof each time.
+- The request for a renewed credential and the profile update that presents it are made on different days.
+- All credentials expiring in the same week have the same expiry.
+
+| Property | Signal badges | SimpleX badges |
+|---|---|---|
+| Account required | Yes | No |
+| Operator holds the list of badge holders | Yes | No |
+| Verified by | The issuing server | Any party with the issuer's public key |
+| Presentations per credential | One | Unlimited |
+| Proof bound to the context of presentation | No | Yes |
+| Expiry rounded up to | The next day | The end of the following Monday |
+| Issuance and presentation on different days | No | Yes |
+| Usable on independently operated servers | No | Yes |
+
+### Non-goals
+
+- A badge does not restrict anything that is available today: the defaults are unchanged, and a badge only raises them.
+- A badge does not create an identity: it has no persistent identifier, it is not linked across conversations, and an incognito profile does not show it.
+- A badge cannot be transferred: a code can be redeemed once for each use it was issued with (usually one), and the credential obtained with it is usable only with the master key it was issued for.
+- A badge does not exempt its holder from the limits a server applies: it lowers the cost of a resource without removing the limit on it.
+- A badge cannot be revoked; credentials are issued for one month at a time instead.
+
+## Architecture
+
+```
+   ┌─────────────────┐   code    ┌──────────────┐   purchase    ┌──────────┐
+   │  Web purchase   │ ────────> │   Holder     │ ────────────> │  Issuer  │
+   └─────────────────┘           │  (the app)   │ <──────────── └──────────┘
+                                 └──────┬───────┘   credential
+                                        │           every month
+                                        │  a new proof each time
+              ┌─────────────────────────┼───────────────────────┐
+              │                         │                       │
+         ┌────▼─────┐             ┌─────▼──────┐          ┌─────▼──────┐
+         │ Contacts,│             │ File       │          │ The user's │
+         │ groups,  │             │ recipients │          │ own servers│
+         │ channels │             └────────────┘          └────────────┘
+         └──────────┘
+```
+
+### Participants
+
+- The issuer is the badge service, a bot on the SimpleX network with a contact address. It holds the secret key with which credentials are signed. Apps and servers hold a list of eight issuer public keys, and every credential includes the index of the key that signed it, so the service can move to the next key without a release of apps or servers.
+- The holder is the app. It keeps the credential in the user's profile, generates proofs on the device, and renews the credential every month.
+- The verifiers are contacts, group members, channel relays, the recipients of files, and the user's own servers. A verifier holds the issuer public keys and no other information about badges.
+
+### Service requests
+
+The app and the badge service communicate through one-off service requests, a primitive of the SimpleX agent described in [One-off requests to service addresses](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2026-07-11-service-rpc.md). Although the service has a contact address, it is not a contact of the app, and no conversation with it exists.
+
+A request is a single message to the service's address. The app establishes a double ratchet, with post-quantum key agreement, from the keys published in the service's address link, encrypts the request with the double ratchet, and sends it to the address queue on the service's server in the same way as any message to a server chosen by another party, that is, through a proxy server when private routing is enabled (which is the default). With the request the app sends the address of a reply queue that it created for this request on one of its own servers. The service decrypts the request with a receiving ratchet initialised from its private keys, sends the reply to the reply queue under the same ratchet, and deletes its state; the app deletes the reply queue and the ratchet when it has the reply or when the request times out.
+
+This exchange has the following properties:
+
+- Unlike a request made directly to the service over HTTP, the app does not connect to the service, nor the service to the app. Each communicates only with SMP servers, so the service does not see the app's network address, and with private routing the service's server does not see it either.
+- Unlike a chat connection, which is a persistent channel through which all requests made over it can be linked to each other, a service request does not create persistent state. Each request uses new keys and a new reply queue, so two requests from the same app cannot be linked by the service or by servers.
+- A reply that decrypts proves that it came from the holder of the keys published in the service's link and signed by its root key, so a server cannot substitute a reply.
+- The badge service answers a repeated request with the same result and does not execute the operation twice, so the app can repeat a request whose reply was lost.
+
+A purchase is identified by an Ed25519 key pair that the app generates for it and does not use for any other purpose. Every request concerning the purchase, the redemption and each monthly renewal, is signed with this key, and the signature covers the request together with a value derived from the ratchet of that exchange, so it is valid for that exchange only and cannot be replayed. The agent verifies the signature and delivers the verified public key to the service with the request, and the service accepts a request about a purchase only when the verified key is the purchase key.
+
+### Buying and redeeming
+
+A badge is bought for one or more months, either on the web or in the app.
+
+On the web the purchase produces a code, which is then redeemed in the app. The code is the only data passed from the web site to the app: the web site does not learn which app redeems a code, and the app does not see the payment. The code is generated in the buyer's browser, and the service stores only its hash; at redemption the app presents the code itself, and the service matches it against the stored hash. A badge issued without a sale, for example in compensation for a problem, is a code generated by the operator, or by a moderator of the service's managed group, and redeemed in the same way.
+
+In the app, the user pays by card, in cryptocurrency, or through the app store. The app requests an invoice from the service, or presents the receipt of the app store, and the service issues the credential once the payment is confirmed.
+
+In both cases the app generates the master key and the purchase key pair before the purchase. To redeem a code, the app sends the code and the master key to the service, which issues the credential. A code redeemed a second time with the same purchase key returns its latest credential; a code redeemed with a different purchase key is refused once all its uses are taken.
+
+### Monthly issuance
+
+A credential is issued for one month at a time, however many months were bought. The service keeps a count of the months remaining for each purchase key, and issues the next credential when the app asks for it. Unused months, e.g. if the app was offline, lapse at the next badge issuance.
+
+Credentials are issued monthly to limit what the expiry date discloses. If credentials were issued for the whole term, a user who bought a year would hold a credential expiring on a day a year ahead, when few other credentials expire, and this date would be disclosed in every proof for a year. Instead, every credential is issued for one month, and its expiry is rounded to the end of the Monday following the end of the paid month (UTC). For example, if the paid month ends on Wednesday 14 October 2026, the credential expires at the end of Monday 19 October, and so does every credential whose month ends between Monday 12 and Sunday 18 October. All credentials whose paid month ends in the same week thus expire at the same instant.
+
+The renewal is split over two days for the same reason. The app requests the next credential on the day before the current one expires, and when the current one expires, it switches to the new one and sends its updated profile to its contacts. In the example above, the app asks the service for the new credential on Monday 19 October and starts showing it on Tuesday 20 October, so an observer of both the request and the profile update cannot correlate them by time.
+
+The renewal runs in the background and does not require any action from the user. Recipients accept a badge for seven days after its expiry, and servers for one day, so a renewal delayed by a few days is not visible to contacts.
+
+### Presentation
+
+A BBS proof is generated over a string, called the presentation header, and is verified only against the same string. The string binds the proof to the context in which it is presented. Without it, a proof received in one conversation could be copied and presented in another. Between apps the string is sent with the proof, and the recipient checks that it is the string it expects; servers know the string already, so it is not sent to them.
+
+The context of a conversation is the same string over which message signatures are computed:
+
+- In a direct chat it is a hash derived from the state of the end-to-end encryption, which only the two sides hold.
+- In a group it is the member's identifier together with the member's signing key.
+- In a channel it is the channel's identifier together with the member's identifier, or the channel's identifier alone when a message is sent in the name of the channel.
+
+A session with a server is identified by the TLS session identifier, which both sides derive from the TLS handshake and which differs on every connection.
+
+Each time the app sends its profile, whether to a new contact, to a group it joins, or to everyone when the profile is updated, it generates a new proof and includes it. The proof is bound to the conversation in which the profile is sent: in a direct chat to the connection with the contact, in a group to the member's identity in that group, and in a channel to the member's identity established by the channel's roster. In a group the badge is accepted only from a message signed with the member's key, and in a channel it is verified against the key that the roster establishes for the member.
+
+A file larger than the default limit is sent with two proofs. The first is placed in the file invitation, the message that announces the file, and is bound to the conversation and to the size of the file; the recipient's app verifies it when the invitation arrives. The second is placed in the file description, the record of where the chunks of the file are stored and how they are decrypted, and is bound in addition to a hash of the description and to the storage time of the file; the app verifies it before the download begins.
+
+### Servers
+
+The client presents the entitlement proof in the transport handshake, bound to the TLS session identifier. The server verifies it once, when the session is established, and applies the result to every command in the session.
+
+The client presents the proof only to its own servers, that is, to those configured for the profile, which are identified by the certificate fingerprint pinned in TLS. It does not present the proof to a server whose address it received from a contact or found in a file description, because a file description names the servers on which the chunks are stored, and these are chosen by the sender. If the app presented its proof to every server it connected to, a sender could store a file on a server of their own and learn, when the file is downloaded, that the person downloading it holds a badge.
+
+On XFTP servers the proof extends the storage time of files. The server grants the smaller of the time requested by the client and the maximum configured for the badge type, and returns the resulting expiry. SMP servers and notification servers accept the same proof in their handshakes but do not yet make use of it.
+
+The exchange between the app and the badge service, that is, the commands, responses and errors, is described in the [badge service protocol](https://simplex.chat/docs/protocol/badges-rpc.md).
+
+
+## Cryptographic primitives
+
+Badges are built on [BBS signatures](https://datatracker.ietf.org/doc/draft-irtf-cfrg-bbs-signatures/), in the BLS12-381-SHA-256 suite, implemented by [libbbs](https://github.com/Fraunhofer-AISEC/libbbs) over [blst](https://github.com/supranational/blst). A credential is a signature over four values under the header `SimpleX badges v1`; a proof discloses three of them and is 304 bytes long. BBS was chosen for four properties that the design needs together:
+
+- A proof can be verified by anyone who holds the issuer's public key, so contacts and independently operated servers verify badges without consulting the issuer.
+- A proof discloses only the values selected.
+- A proof cannot be linked to any other proof of the same credential.
+- A proof is generated over a presentation header, so it can be bound to the context in which it is presented.
+
+Credentials of the kind Signal uses can be verified only by their issuer, and a receipt credential discloses its serial number when presented, so it is presented once. Single-use tokens, such as blind signatures and the tokens of Privacy Pass, are likewise spent when presented and do not include values such as an expiry or a type.
+
+Service requests are protected by the double ratchet of the [SimpleX agent](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/agent-protocol.md), with X448 key agreement and the sntrup761 KEM, established from keys published in the service's link. The purchase keys with which requests are signed, and the member keys that form part of the conversation context in groups, are Ed25519 keys. Codes are hashed with SHA-256, and the file description in the context of a file proof with SHA-512.
+
+
+## Security
+
+### Design objectives
+
+1. A proof discloses no value that links it to another proof or to the purchase.
+2. A proof used in one context, whether a session, a conversation or a file, cannot be used in another context.
+3. The timing of presentations does not identify the holder: all credentials expiring in the same week share the same expiry, and the renewal request and the profile update are made on different days.
+4. Requests to the badge service cannot be linked to each other, to a profile or to a network address, other than the redemptions of one multi-use code and the codes issued in the service's managed group or redeemed by its members, and a request about a purchase can be made only by the holder of the purchase key.
+5. A credential cannot be forged: the issuer keys are fixed in apps and servers, and the app verifies a credential before storing it.
+6. A missing or failed proof leaves the default limit in place, and a server cannot be configured to grant a badge type less than the default.
+
+### Threat model
+
+This threat model assumes the [SimpleX network threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/security.md) and addresses the threats specific to badges.
+
+**The badge service**
+
+*can:*
+
+- See the purchase key of every badge, the master key generated for it, the number of months bought, and the payment record.
+- Issue any credential, or refuse to issue one, as it holds the issuer key.
+- Link a code issued in its managed group to the member who asked for it and to that group, as the group's messages, codes included, are kept in the service's chat database.
+- Link a redemption to a member of its managed group whose profile shows a new badge soon after it.
+
+*cannot:*
+
+- Connect a purchase with a profile, a contact, a group or a session with a server, other than a code issued in its managed group or redeemed by one of its members, as above - a proof contains nothing that refers back to the purchase.
+- Learn where a badge is shown or used.
+- Learn the network address of the app - requests reach the service through SMP servers, on connections created for the request.
+
+**A contact, a group member or a channel relay**
+
+*can:*
+
+- See the badge type and the expiry date.
+
+*cannot:*
+
+- Tell whether a badge seen in another conversation belongs to the same person.
+- Reuse a profile proof or a file proof in another context.
+- Distinguish the holder from the other supporters whose badges expire in the same week.
+
+**A member of the badge service's managed group**
+
+*can:*
+
+- Redeem any code issued in the group that is not revoked and has uses left, as every code is posted to the group.
+- See when each use of a multi-use code was redeemed.
+- Issue free codes of any type as a moderator or above, and revoke any code whose text they hold as an admin or above.
+- Become the group's owner by being the first to join it, before an owner is set up.
+- Guess who redeemed a code, when a member's profile shows a new badge soon after the code's message changes.
+
+*cannot:*
+
+- Redeem a revoked code, or a code with no uses left.
+
+**A server operator**
+
+*can:*
+
+- See the badge type and the expiry date once in each session.
+- Group together the sessions of the supporters whose badges expire in the same week.
+
+*cannot:*
+
+- Reuse the proof on another connection.
+- Link a session to the purchase, to a profile or to sessions on other servers, except through the week of expiry.
+- Obtain a proof from a client that does not use the server.
+
+**The server that hosts the badge service's address**
+
+*can:*
+
+- See that requests arrive for the service.
+
+*cannot:*
+
+- See the content of requests.
+- See the network address of the app when private routing is used.
+- See the replies, which are sent to a queue on a server chosen by the app.
+
+**One badge on many machines**
+
+Since proofs are unlinkable, a server cannot count the sessions of a single credential, so the benefit granted by a badge must be limited without counting sessions. For this reason a badge lowers the cost of a resource without removing the limit on it, and limits per session remain in force.
+
+**Compromise of the user's device or backup**
+
+An attacker who obtains the credential and the purchase key can use the badge until it expires and renew it while months remain. There is no revocation, so the loss is limited to the months bought.
+
+**Interception of a code**
+
+A code is a bearer secret until its last use is taken; after that, it is refused to any other purchase key.
+
+**A passive network observer**
+
+*can:*
+
+- Observe SimpleX traffic between clients and servers.
+
+*cannot:*
+
+- See a proof - proofs to servers are inside TLS, in a handshake block of fixed size, and proofs to other users and requests to the badge service are inside end-to-end encrypted messages.
+- Distinguish a session in which a proof was presented from a session without one.
+
+## Future work
+
+- Backups will be stored on XFTP servers, and a badge will raise their size and their storage time, as described under [What a badge grants](#what-a-badge-grants).
+- SMP servers and notification servers will verify the proof. A server that verifies it can charge the holder of a badge less for creating queues, file chunks and notification tokens (under the planned proof-of-work scheme, the required effort is divided by a factor configured for each badge type), and can apply higher rate limits and larger quotas.
+- Subscriptions that renew automatically, the transfer of remaining months to a new device, and the pausing of a prepaid badge are planned.
diff --git a/docs/protocol/badges-rpc.html b/docs/protocol/badges-rpc.html
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         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/protocol/badges-rpc.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/protocol/badges-rpc.md b/docs/protocol/badges-rpc.md
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+# Badge service RPC protocol
+
+Schema: `badges-rpc.schema.json`, definitions `request` and `response`. Types: `Simplex.Chat.Badges.Service`. Model: `plans/2026-07-30-supporter-badges-v3-ux.md` §3 — cited below as "model".
+
+## Transport
+
+Service RPC (`plans/2026-07-22-service-rpc-chat.md`, branch `rpc`): the request travels in `APISendServiceRequest.request`, the response in `CRServiceResponse.responseData`; one response per request; per-call timeout.
+
+A request is an envelope: `version` — the client's protocol version; `purchaseKey`; `request` — the command, discriminated on `type`. Responses are discriminated on `type`. The service is deployed ahead of app releases, answers within the client's `version`, and rejects clients older than it supports with `unsupported_version`.
+
+## Identity
+
+Each purchase runs under a fresh Ed25519 key pair; `purchaseKey` is its public part and identifies the badge. The service cannot link purchases of one user; the exceptions are the declared upgrades below. `getBadgeCatalog` may omit `purchaseKey`: unsigned, it returns the catalog alone; signed, its response adds the purchase's `badgeStatement` — a client holding a lapsed badge checks for credits in the same request that prices a new purchase, and buys under a fresh key only when the statement shows none. Every other command requires the key and is signed with it. The agent delivers the verified signer key alongside the request; the service rejects a `purchaseKey` that differs from it with `bad_request`.
+
+A purchase record is created by `redeemBadgeCode`, by `getBadgeInvoice`, or by `purchaseBadge` funded with `apple`, `google`, or `receipt`. Those commands accept a key the service holds no record of — on a first purchase it always will. Every other command answers `unknown_purchase_key` for such a key.
+
+## Idempotency
+
+A timeout hides the outcome, so the client repeats the identical signed request at its next trigger, never on a poll timer.
+
+- `getBadgeInvoice` — returns the open invoice again; a new invoice is created only when none is open.
+- `redeemBadgeCode` — a code already redeemed by the signing key returns its latest `badgeCredential` and writes nothing; once other keys have taken all its uses, `code_used`. The client must therefore keep the key it first signed with, or a retry cannot be recognised.
+- `purchaseBadge` — a payment already credited returns the same `badgeCredential` and writes nothing.
+- `upgradeBadgeSubscription` — evidence already applied returns the same result and writes nothing.
+- `issueBadge` — repeated within an issued period, returns the cached credential and writes nothing.
+- `purchaseBadge` with a `receipt` — presented again by the same key it returns the same result; presented by another key, `receipt_used`.
+
+## Commands
+
+`purchaseBadge` and `upgradeBadgeSubscription` carry `badgeRequest`, the signer's input (`BadgeRequest`, `Simplex.Chat.Badges`): the service signs exactly this content or rejects the command. The proposed `badgeExpiry` is capped by the funded coverage (`sundayAfter`, model §3) and is required — a credential always expires, and a badge that does not is expressed as a long finite term; `badgeExtra` is reserved and must be empty. `issueBadge` carries no `badgeRequest`: the tier, the master key and the expiry are all the service's own, so there is nothing for the client to state.
+
+- `getBadgeCatalog` → `badgeCatalog` — the prices and offers; signed, also the purchase's `badgeStatement`. Store builds never send it: prices come from the store and SKUs from app config.
+- `getBadgeInvoice` → `badgeInvoice` — prices the purchase for `badgeInfo` and `paymentVia` (`card` — Stripe; `crypto` — btc, xmr). The response holds the generic `invoice` — `invoiceId`, `price`, `discount`, the upgrade `credit`, `amount` = price − discount − credit, `currency`, `expiresAt`, and `paymentTo` (`url` for card; `address` and `cryptoAmount` for crypto) — beside the badge part, `badgeType` and `months`. `priceId` pins the price the client displayed; `offerId` selects a discounted duration, and its absence buys one month at that price. Price and offer status is checked here only: `deprecated` is still accepted, `disabled` is rejected; a badge type with no active price yields `product_unavailable`.
+- `redeemBadgeCode` → `badgeCredential` — redeems a code, records the credit, and issues the first credential, in one round trip. It carries `masterKey` and `code` and no `badgeRequest`: a code states no tier and no expiry, so the credential is what reports them. Errors: `code_invalid` for an unknown or malformed code, `code_used` when other keys have taken all its uses (a code has one use unless issued with more), `code_expired` past a redemption deadline.
+- `purchaseBadge` → `badgeCredential` — verifies the funding (`apple` JWS offline; `google` token via the Publisher API; `invoice` against webhook-confirmed settlement, `payment_pending` until it lands; `receipt`), records the credit, and issues the first credential, in one round trip. The response `receipt` is the recovery bearer secret (model § recovery); the service stores its hash; lifetime badges receive none.
+  - Funding by `receipt` is a transfer (post-MVP): the unissued months of the purchase that receipt belongs to move to the signing key, recorded as `debit(transferOut)` on the source and `credit(transferIn)` on the new purchase, and the presented receipt is retired for a fresh one. The transferred period's issuance debits a month like any other. Lifetime badges hold no receipt, so support handles them.
+- `upgradeBadgeSubscription` → `badgeCredential` — the app-led store subscription change, on the same key: verifies the store evidence of the replaced subscription and records the new plan; an immediate upgrade returns the new credential, a deferred change returns none.
+- `issueBadge` → `badgeCredential` — issues the next period from the balance, the only source of issuance. It carries `balance` alone: the credential is signed with the purchase's stored master key, for the type the balance funds, expiring at the `sundayAfter` of the period issued. The ledger is advanced first; the credential is signed before the `debit(badge)` and issuance rows are written, in one transaction. An exhausted balance yields no `credential`; the `statement` shows why. Issuing on a paused badge resumes it (model 2.13).
+- `pauseBadge` (post-MVP) → `badgeCredential` — suspends issuance and lapse (model 2.13).
+
+## Upgrades
+
+Always a new purchase under a new key, except store subscriptions, where the store owns the change.
+
+- Non-store: `getBadgeInvoice.upgrade` — `fromPurchaseKey`, the old purchase's `receipt`, `receiptSignature` binding the old key to the new, and the asserted old `balance`. The invoice returns the conversion `credit`; settlement records `debit(upgrade)` on the old purchase and the credit on the new.
+- Store one-time: an upgrade SKU at a fixed discounted price; `purchaseBadge.upgrade` — `fromPurchaseKey`, `receipt`, `receiptSignature` — proves eligibility (an unexpired cheaper badge), because the store cannot gate who buys the SKU.
+- Store subscription, app-led: the native subscription-group flow (Apple — immediate, with the store's prorated refund; Google — per replacement mode), then `upgradeBadgeSubscription` with the new evidence.
+- Store subscription, sheet-led, and every downgrade: the client sends nothing — the service discovers the change from provider state and notifications, and each renewal credits months of the charged badge type.
+
+## Catalog
+
+`prices` — `priceId`, `badgeType`, `monthPrice`, `currency`, `status`, `createdAt`; `offers` — `offerId`, `priceId`? (absent applies to any price), `months`, `discount`, `status`, `createdAt`. An offer states a discount, as free months or a percentage; a duration without one is priced at `months × monthPrice`. Repricing appends a price and deprecates the old, which is still accepted at invoice creation; deprecated prices and offers are sent so that a refresh cannot remove what the client pinned, and disabled ones are omitted. Rendering is app-driven — tiers and durations come from app resources, and one without a price is shown disabled.
+
+## Statement and balance
+
+The ledger is written by the service alone (model §3); the client keeps a verbatim replica and computes the effective balance from its last entry and the time. Month boundaries are counted from `balanceAnchorTs`, the start of the current run of months, and not from `balanceStartTs` — counting from the moving start would compound the day-of-month clipping of a short month, so a run beginning 31 January would reach 28 February and never return to the 31st. The service sets a new anchor only where a lapsed run restarts; months granted while coverage still runs extend it on its existing anchor.
+
+`statement` — `entries`, and `previousEntryId` when they attach after an entry the client holds; its absence marks entries that attach to nothing. Each entry states `entryId`, the signed `changeMonths`, the resulting `balanceMonths`, `balanceStartTs`, `balanceAnchorTs`, and `balanceBadgeType`, `wasPausedSince` on the entry ending a pause, `createdAt`, and `entryType` — `credit`: `payment {invoiceId?}`, `code`, `charge {chargeId}`, `support`, `transferIn {fromPurchaseKey}`, `opening`; `debit`: `refund`, `upgrade {toPurchaseKey}`, `transferOut {toPurchaseKey}`, `support`, `badge`, `lapse`. A code grant is `code` rather than `payment` with no `invoiceId`: the invoice of a code belongs to whoever bought it, and the redeemer's ledger must never reference it. An unknown type is stored as received and decoded after an app upgrade.
+
+`balance` — `lastEntry`, the client's last entry, asserting the position and the months it believes it holds.
+
+An assertion that names an entry the service holds is a prefix: the service proceeds and returns what follows it. Otherwise the service heals its own ledger first — provider evidence for charges, time for lapses — proceeds, and returns either the complete history or one `opening` credit. An `opening` entry is an absolute restatement: the ledger is reset to the amount it states, without relation to the preceding entry, which also serves a new device and, later, the discarding of old history into a brought-forward balance.
+
+## Errors
+
+`retryAfter` marks the transient codes: `payment_pending`, `provider_unavailable`, `rate_limited`. `offer_disabled` calls for a catalog refresh. `code_invalid` covers unknown, malformed and revoked codes alike, so a guesser learns nothing from the difference; `code_used` — all its uses taken by other keys; `code_expired` — past its redemption deadline. `receipt_invalid` covers unknown receipts. All other codes are terminal for the attempted command.
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         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/protocol/channels-overview.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
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diff --git a/docs/protocol/channels-overview.md b/docs/protocol/channels-overview.md
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+Revision 1, 2026-04-28
+
+# SimpleX Channels: stateful information delivery and management
+
+## Table of contents
+
+- [Introduction](#introduction)
+  - [What are SimpleX Channels](#what-are-simplex-channels)
+  - [Channels as transport layer](#channels-as-transport-layer)
+  - [Content visibility and participant privacy](#content-visibility-and-participant-privacy)
+  - [In comparison](#in-comparison)
+  - [Non-goals](#non-goals)
+- [Architecture](#architecture)
+  - [State and distribution](#state-and-distribution)
+  - [Identity and ownership](#identity-and-ownership)
+  - [Governance](#governance)
+  - [Roles](#roles)
+- [Cryptographic primitives](#cryptographic-primitives)
+- [Security](#security)
+  - [Design objectives](#design-objectives)
+  - [Signing scope: roster only, content optional](#signing-scope-roster-only-content-optional)
+  - [Threat model](#threat-model)
+  - [Current gaps](#current-gaps)
+- [Future work](#future-work)
+  - [Stateful access and history navigation](#stateful-access-and-history-navigation)
+  - [Transcript integrity](#transcript-integrity)
+  - [End-to-end encrypted side conversations](#end-to-end-encrypted-side-conversations)
+  - [Relay addition and removal](#relay-addition-and-removal)
+  - [Governance evolution](#governance-evolution)
+  - [Pre-moderation](#pre-moderation)
+  - [Scheduled delivery](#scheduled-delivery)
+  - [Link preview proxying](#link-preview-proxying)
+- [Conclusion](#conclusion)
+
+
+## Introduction
+
+The SimpleX network provides private point-to-point communication without user or endpoint identifiers, but most speech that matters is public. Every existing platform that distributes content at scale identifies both publishers and their audiences to the operator - none protect participation privacy. SimpleX Chat supported peer-to-peer groups, but they cannot scale to large audiences. SimpleX Channels close this gap.
+
+### What are SimpleX Channels
+
+SimpleX Channels are a stateful information delivery and management layer built on the [SimpleX network](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md). SMP queues provide stateless, unidirectional packet delivery between two endpoints. Channels add persistence, state, and scalable distribution - enabling one-to-many publishing with cryptographic identity independent of infrastructure operators.
+
+[SimpleX Chat](https://simplex.chat) is the first application, presenting channels as a broadcast publication model where owners publish and subscribers read, react, and comment. But channels are not limited to this use case - they are a general-purpose layer for distributing and managing stateful information (feeds, telemetry, automated pipelines, coordination services, social media). This document describes channels as a transport mechanism - the same mechanism will also be used for large groups, communities, wikis, forums, and other social media primitives.
+
+The critical difference from conventional publish-subscribe systems is that channel identity and governance are controlled cryptographically by the channel owners, not by the infrastructure operators. Relays - SimpleX network clients that forward and optionally cache channel content - can be added, removed, and replaced without changing the channel's identity, address, content, or cryptographic trust chain. A channel's relationship with its relays is transient; its identity is permanent. The authoritative record of content is hosted on channel owners' devices; relays perform transmission and caching similar to CDN infrastructure.
+
+Channel owners hold full control of the channel - its identity, content, governance rules, and membership - through self-custody of cryptographic keys. No infrastructure operator, relay provider, or third party can control or alter a channel without the owner's keys. Blockchain systems achieve a related property for financial assets - no third party can control holdings - through network-wide consensus. Channels achieve it through local authority and cryptographic signatures, without global consensus or a public ledger. Unlike blockchain state, channel state is mutable by the owner and not publicly verifiable by third parties.
+
+### Channels as transport layer
+
+The SimpleX network has three transport layers, each built on the one below:
+
+1. **SMP** ([SimpleX Messaging Protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/simplex-messaging.md)) - stateless, unidirectional packet delivery between two endpoints through SMP routers. Provides fixed-size blocks, 2-node onion routing, and transport metadata protection.
+
+2. **SimpleX agents** ([agent protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/agent-protocol.md)) - bidirectional, redundant connections between endpoints, with end-to-end post-quantum double ratchet encryption. The [SimpleX Chat Protocol](https://simplex.chat/docs/protocol/simplex-chat.md) runs on top of this layer, providing direct messaging, group communication, and metadata delivery for file transfers via [XFTP protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md).
+
+3. **Channels** - stateful, one-to-many information delivery and management with cryptographic ownership and programmable governance. This layer runs on top of chat and agent layer 2, and it is described in this document.
+
+No network-wide user profile identifiers exist at any of these layers. Just as SMP enables private messaging by providing transport without user identifiers, channels enable public communication while preserving participation privacy at the distribution layer.
+
+Channel relays are themselves SimpleX clients in the SMP network, connecting to SMP routers using the same protocol, the same 2-node onion routing, and the same fixed-size transport blocks as any other endpoint. Even though the SMP network can distinguish a relay from a person's phone by its transport patterns, it prevents relays from learning anything about other network endpoints. In the case of SimpleX Chat, any CLI client can act as a chat relay without modifications.
+
+Channels therefore inherit all of SMP's transport privacy properties:
+
+- **Relays cannot observe subscriber network addresses.** The relay sees SMP queue addresses, not IP addresses or network sessions. The subscriber's IP is known only to their SMP router, which cannot see the message content (encrypted at the agent layer) or the IP addresses of whoever sends messages.
+
+- **SMP routers cannot see channel content.** Messages between relay and subscriber are end-to-end encrypted. The SMP router forwards fixed-size encrypted blocks without knowing whether they carry channel messages, direct messages, or anything else.
+
+- **Participation in multiple channels is unlinkable.** Each channel connection uses independent SMP queues with separate cryptographic credentials. Because of packet-level anonymity in 2-node routing, even if a subscriber uses the same SMP routers for all channels, the sending relays cannot determine this without collusion with those routers. Clients choose independently operated routers by default.
+
+No single point in the system sees both content and network identity. SMP routers see network addresses but not content, and no single SMP router can see which endpoints are communicating because clients choose independently operated routers. Relays see content but not network addresses.
+
+### Content visibility and participant privacy
+
+Any channel joinable via a public link, whether encrypted or not, must be considered completely public - the cost of joining through automated means has collapsed with large language models and is approaching zero. End-to-end encrypting such content provides no privacy; it only undermines users' security by creating false expectations and increases infrastructure operators' risks by making them unable to see what they deliver. Private channels with encrypted content are a separate use case discussed in [Future work](#end-to-end-encrypted-side-conversations).
+
+Content of public channels is therefore not end-to-end encrypted between owner and subscriber. Relays can read the messages they forward. Relay operators cannot undetectably alter channel content when multiple relays serve the channel, and cannot alter signed content at all - the authoritative state is held by owners. That each channel can use multiple chat relays provides both technical reliability and censorship resistance against any relay-specific content policies.
+
+The achievable privacy property for public communication is participation privacy - protecting who reads and writes content. The SMP transport carries no user identifiers, and relays are ordinary SMP clients, so subscribers connect without revealing their identity, network address, or any information that persists across channels. If an adversary joins a SimpleX channel, they see everything that is sent, but cannot determine who sent it or link any participant to anything outside the channel.
+
+Other systems make the opposite choice: content encryption in exchange for participant identification. For groups and channels joinable via public links this is the opposite of what is needed - the content encryption is meaningless (anyone can join and read), while the participant identification is the security threat.
+
+### In comparison
+
+**Telegram channels** - the operator controls channel identity (usernames are revocable), has full access to both content and participant identity. Channels cannot exist without Telegram's permission.
+
+**Nostr relays** - a single persistent key is used for publishing, following, and identity. Relays see content, the user's key, and their IP address. All posts and follow lists are signed and non-repudiable, linked to the same key - making both publishing and reading activity traceable and undeniable.
+
+**Signal groups** - content is end-to-end encrypted, but the operator manages group state and can observe the membership graph. Groups are capped at 1,000 members with no concept of a channel.
+
+**Matrix rooms** - server operators see room membership and metadata. Room identity is bound to the creating server's domain - if the server disappears, the room identity is lost.
+
+**Mastodon / ActivityPub** - publisher identity is bound to a server domain - if the server disappears, the identity is lost. Server operators see all content and all follower relationships. No encryption or privacy of any kind.
+
+| Property | Telegram | Nostr | Signal | Matrix | Mastodon | **SimpleX** |
+|---|---|---|---|---|---|---|
+| Content visible to operator | Yes | Yes | No | Configurable | Yes | **Yes** |
+| Participant identity visible to operator | Yes | Yes | Yes | Yes | Yes | **No** |
+| Channel identity independent of infrastructure | No | Yes | No | No | No | **Yes** |
+| Sovereign ownership (no 3rd party can seize) | No | Yes | No | No | No | **Yes** |
+| Programmable governance | No | No | No | No | No | **Planned** |
+| Cryptographic content deniability | No | No | Yes | Yes | No | **Yes (default)** |
+| Scalable one-to-many delivery | Yes | Yes | No | Limited | Yes | **Yes** |
+
+### Non-goals
+
+Channels do not attempt to:
+
+- **Encrypt public content from relay operators.** See [Content visibility and participant privacy](#content-visibility-and-participant-privacy).
+- **Assign persistent identities to participants.** There are no usernames, public keys, or any identifiers that persist across channels or link activity across contexts.
+- **Require network-wide consensus.** Channel state is authoritative on owner devices. The network does not validate channel transactions.
+- **Guarantee immutability of content.** Channel state is fully controlled and mutable by owners, unlike blockchain state, which is immutable by design.
+
+## Architecture
+
+The introduction established what channels provide and why. This section describes how: where state lives, how identity and ownership work, how governance evolves, and what each participant does.
+
+### State and distribution
+
+The authoritative record of a channel - content, member roster, profile, cryptographic keys, governance rules - is held by channel owners on their own devices, not on relays, not on any server, and not on any shared ledger. Relays hold transient copies for distribution and optional caching, analogous to CDN edge nodes: the origin holds the truth, CDN nodes come and go. Consensus is only required between channel owners, not across the entire network.
+
+```
+                     ┌──────────┐
+                     │  Owner   │  <- authoritative state
+                     └────┬─────┘
+                          │
+              ┌───────────┼───────────┐
+              │           │           │
+         ┌────▼───┐  ┌────▼───┐  ┌────▼───┐
+         │Relay A │  │Relay B │  │Relay C │  <- cache / distribution
+         └────┬───┘  └────┬───┘  └────┬───┘
+              │           │           │
+        ┌─────┼─────┐    ...    ┌─────┼─────┐
+        │     │     │           │     │     │
+       S1    S2    S3          S7    S8    S9   <- received copies
+```
+
+Content originates on the owner's device and flows through relays to subscribers. Each relay independently forwards to all of its subscribers. Subscribers do not connect to owners or to each other - this provides better scalability than peer-to-peer SimpleX groups, where adding a member requires N new connections. When multiple relays serve the same channel, subscribers deduplicate at the client level.
+
+**Failure modes:**
+
+- **Loss of a relay is loss of a cache node, not loss of data.** The owner can send the same content through a replacement relay.
+
+- **Loss of all owner devices is the catastrophic event** - relay caches become orphaned and the channel's private keys are gone. Multiple owners and backups mitigate this risk.
+
+- **Disagreements between relays are resolved by the origin.** The owner's version is authoritative, settling cache inconsistency through any reachable relay.
+
+Subscribers hold their own received copies. Signed messages are independently verifiable without consulting the relay or owner. Unsigned content depends on cross-relay consistency or future transcript integrity mechanisms.
+
+### Identity and ownership
+
+A channel's identity is the SHA-256 hash of the genesis root public key, computed at creation time and never changed - even if relays are added, removed, or the channel link is rotated. It is self-authenticating: derived from a key pair that only the channel creator held. It is embedded in the channel's link, distributed in the profile to all members, and used as a binding prefix in all signed messages.
+
+Subscribers validate that the identity in the link matches the identity in the profile, preventing link substitution. Profile updates that attempt to change the identity are rejected. Full validation that the identity equals the hash of the root key is deferred: if current clients enforced this check, they would reject future rotated links as invalid. The identity is correctly managed today; validation will be enforced with the key rotation protocol. See the [group identity binding RFC](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2026-03-28-group-identity-binding.md).
+
+The root key does not sign messages directly. Instead, it authorizes owner keys through a signed chain. At creation, the owner generates a root key pair and a separate member key pair for signing. The member key is published as an authorization entry signed by the root key. New owners can be added by any previously authorized owner signing a new entry. Anyone retrieving the channel link can verify this chain without network access.
+
+The root key is a bootstrap key - it certifies owners, then need not be used again. All owners are cryptographically indistinguishable to subscribers (they all have equally valid authorization chains), which - provided multiple owners were signed by the root key - conceals the creator's identity.
+
+The channel link is the out-of-band trust anchor - relays and SMP routers cannot modify link content. All members announce their signing keys on joining. Owner keys are verifiable against the link. Role changes (promoting members to admin, moderator) are signed by owners at the protocol level.
+
+A planned extension will record role changes as a linearly ordered signed roster log with consistent sequencing across all owners, relays, and subscribers. This linearization prevents ambiguous roster states from concurrent unordered changes, and creates a verifiable chain of trust from the channel link through owners to all elevated roles. Out-of-band key verification for non-owner members will further extend this to E2E encrypted conversations.
+
+### Governance
+
+"Management" in "information delivery and management" refers not only to managing content but to managing the channel itself - who can make decisions, and how.
+
+The low-level protocol supports multiple owners from the initial release. The application-level governance model evolves through a planned progression:
+
+**Current (v6.5): Single owner.** One owner controls the channel. All administrative actions (profile changes, roster modifications, relay management) are decided by this single owner. The protocol-level owners chain supports verification of multiple entries, but the application creates and manages only one.
+
+**Near-term (v7): Multiple owners, any-owner-decides.** Multiple owners share control of the channel. Any owner can independently make any administrative decision - add or remove members, change the profile, manage relays. This is the most common decision-making model in practice (equivalent to "all admins are equal" in most online platforms). No coordination between owners is required for any action.
+
+**Future: Multisig and programmable governance.** Further stages include M-of-N multisig for administrative actions and, eventually, programmable governance rules defined as code in the channel's definition. The protocol must support these without prescribing a specific governance model.
+
+### Roles
+
+- **Owners** create the channel, hold the authoritative state and private keys on their devices, publish content, and manage the member roster. Owners sign administrative messages and optionally content messages. A channel must have at least one owner.
+
+- **Relays** receive content from owners and members with posting rights, optionally cache it, and forward it to subscribers. They accept new subscriber connections and introduce them to the channel owners. Relays cannot author messages. A channel must have at least one active relay. Relays are ordinary SimpleX clients - a relay can be operated by anyone (a channel operator, a third-party service provider, or a self-hosted instance) and each creates its own contact address link, bound to the channel's identity. The relay's relationship with the channel is transient - owners can add and remove relays without changing the channel's identity.
+
+- **Subscribers** connect to relays and receive content. They cannot send messages by default, but can be given posting rights.
+
+Additional roles (moderator, admin, member, author) exist in the hierarchy and are inherited from the group protocol. The owner-signed roster tracks the promoted set - members, moderators, and admins; subscribers are observers until an owner promotes them.
+
+For protocol-level detail - wire formats, message types, signing and verification mechanics, delivery pipeline - see [SimpleX Channels Protocol](https://simplex.chat/docs/protocol/channels-protocol.md).
+
+
+## Cryptographic primitives
+
+- **Ed25519** - channel identity (root key pair), owner authorization chain, and message signing. The signature binding prefix includes the channel's entity ID and the sender's member ID, preventing cross-channel replay.
+
+- **SHA-256** - derives the channel's entity ID from the genesis root public key. Immutable, serves as the channel's permanent identity.
+
+- **Double ratchet with post-quantum KEM** (inherited from [SimpleX agent layer](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/agent-protocol.md)) - end-to-end encryption for all SMP transport. Not channel-specific - channels inherit it by being built on the agent layer. Future E2E side conversations (support scope, member DMs, private channels) will use the same mechanism.
+
+Content messages are not signed by default to preserve cryptographic deniability - see [Signing scope](#signing-scope-roster-only-content-optional). Owners may opt into signing all content in a future release.
+
+
+## Security
+
+This section examines what the architectural properties protect against, where they hold, and where gaps remain.
+
+### Design objectives
+
+The channel protocol is designed to achieve the following security objectives:
+
+1. **Stable message delivery** between channel participants, resilient to individual relay failures.
+2. **No possibility for a relay to substitute the channel** - the channel's identity is cryptographically bound to the link and profile controlled by channel owners.
+3. **No possibility for a relay to impersonate an owner** - administrative messages require valid signatures.
+4. **Prevention of relay-initiated roster manipulation** - member removal, role changes, and other roster modifications require valid owner signatures.
+5. **Relay transience** - the owner can add and remove relays, including the last relay, without permanently losing the channel. Subscribers can restore connectivity by retrieving updated link data.
+6. **Sender anonymity within multi-owner channels** - owners can publish as the channel, hiding which specific owner authored a message from subscribers.
+7. **Participant privacy** - relay operators cannot determine subscriber identity or network address, and subscribers cannot determine each other's identity. This is inherited from the SMP transport layer.
+
+### Signing scope: roster only, content optional
+
+By default, only roster-modifying and administrative messages are signed. Content messages are not signed. Two reasons:
+
+1. **Cryptographic deniability.** Signing creates non-repudiable proof of authorship verifiable by any third party. Without signatures, no such proof exists - a relay could have fabricated any unsigned message.
+
+2. **Proportional defense.** Changes to roster, channel profile, and permissions can be disruptive and irreversible - they must be authenticated at processing time. Content manipulation is detectable post-hoc through cross-relay consistency, and the authoritative record on the owner's device is unaffected.
+
+Owners will be able to opt into signing content on a per-channel or per-message basis - some publishers want non-repudiable authorship, others prefer deniability.
+
+### Threat model
+
+This threat model assumes the [SimpleX network threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/security.md) and addresses threats specific to the channel layer.
+
+**A single compromised relay**
+
+*can:*
+
+- Substitute unsigned content or selectively drop messages for its subscribers. Detectable by subscribers connected to other relays - the owner's version is authoritative. TODO: difference detection not yet implemented.
+- Selectively target specific subscribers while delivering correctly to others.
+- Ignore the "message from channel" directive, revealing which owner sent a message. Detectable out-of-band.
+- Fabricate or hide subscriber connections, inflating or deflating counts. Detectable if subscribers are connected to other relays.
+
+*cannot:*
+
+- Undetectably substitute content - subscribers on honest relays receive the original.
+- Alter the channel's authoritative state on the owner's device.
+- Substitute the channel profile or impersonate an owner - these require valid signatures.
+- Replay an old roster or role change to re-elevate a removed or demoted member for existing subscribers - they reject anything older than the roster version they applied (a new joiner with no prior roster can still be served an old one, until it syncs from another relay).
+- Redirect subscribers to a different channel - the entity ID is validated across link and profile.
+- Determine subscriber identity or network address - inherited from SMP transport.
+- Correlate subscriber participation across channels - each connection uses independent SMP queues. The subscriber chooses their SMP router independently, so collusion between a relay and the relay's SMP router does not compromise connections through a different router.
+
+**All relays compromised and colluding**
+
+*can:*
+
+- Undetectably substitute unsigned content for all subscribers, unless owners sign content messages.
+- Prevent delivery of any messages, including signed ones (signing prevents substitution, not dropping).
+- Fabricate or hide subscriber connections undetectably.
+
+*cannot:*
+
+- Forge signed administrative messages or substitute the channel profile.
+- Alter the authoritative state on the owner's device.
+
+**Compromise of owner keys**
+
+An attacker who obtains the root private key or an owner's member private key (through device compromise, backup theft, or coercion) can impersonate the owner and sign arbitrary administrative messages. This is a different threat from key loss - the channel continues operating, but under adversarial control. Mitigation depends on owner-side operational security and future multisig governance. For the threat model of the channel link itself (the trust anchor), see the [short links for groups RFC](https://github.com/simplex-chat/simplexmq/blob/stable/rfcs/2025-04-04-short-links-for-groups.md).
+
+**Loss of all owner devices**
+
+The channel can have no new content, no administrative updates, no new owners. Relay caches continue delivering existing content but cannot be refreshed, and will eventually expire in the absence of the owner connection. Multiple owners and key backups mitigate this risk.
+
+**A subscriber**
+
+*can:*
+
+- See all public content, by design.
+- Join multiple times with different profiles, inflating counts.
+
+*cannot:*
+
+- Identify other subscribers, send messages to the channel (unless given posting rights), or forge messages of the owner or other subscribers.
+
+**A passive network observer**
+
+*can:*
+
+- Observe communication with an SMP router, but not whether it is channel-related.
+
+*cannot:*
+
+- Determine which channel a subscriber uses, correlate channel activity with other SimpleX activity, or identify a relay as distinct from an ordinary user, other than by traffic volume. Inherited from SMP transport.
+
+### Current gaps
+
+1. **Cross-relay consistency detection.** Duplicate messages are silently deduplicated without hash comparison. Designed but not implemented.
+2. **Link entity ID validation.** Deferred to a future version with key rotation. See [group identity binding RFC](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2026-03-28-group-identity-binding.md).
+3. **Multi-relay UX.** Protocol supports multiple relays per subscriber; no UX for monitoring relay-level delivery health. It will be added in v6.5.x.
+
+
+## Future work
+
+### Stateful access and history navigation
+
+Currently, relays send recent cached history on join but do not support navigation or search. Planned: history pagination by timestamp or message ID, remote search against relay caches, and selective retrieval of specific message ranges. Relay operators can differentiate on cache depth and search capabilities.
+
+### Transcript integrity
+
+- **Opt-in content signing.** Per-channel or per-message choice to sign content, making it non-repudiable. This will be released in SimpleX Chat v7.
+- **Subscriber transcript acknowledgment.** Subscribers periodically sign a digest of received history ("I've seen it" rather than "I've authored it"), enabling detection of relay manipulation through diverging digests.
+- **Merkle tree signing.** Owner periodically publishes a signed Merkle root. Subscribers verify their copies against the owner's authoritative record.
+
+### End-to-end encrypted side conversations
+
+- **E2E encrypted support scope** between subscriber and moderator/owner.
+- **E2E encrypted DMs between members** where channel settings permit, using standard SimpleX connection establishment.
+- **Private channels** where the entire content stream is encrypted to authorized subscribers. The relay becomes a conduit that sees neither content nor identity.
+
+### Relay addition and removal
+
+Dynamic relay addition with cache population from existing relays or owner. Relay removal with subscriber migration. Relay rotation with continuity - new relay connects before old relay is removed. It will be added in v6.5.x.
+
+### Governance evolution
+
+- **Multiple owners (v7):** concurrent administrative authority, any owner acts independently.
+- **Multisig:** M-of-N approval for administrative actions, with per-action quorums.
+- **Programmable governance:** rules defined as code in the channel definition.
+
+### Pre-moderation
+
+Subscriber messages reviewed by moderators before becoming visible to all subscribers.
+
+### Scheduled delivery
+
+Messages scheduled for future delivery, cached by relay until the scheduled time.
+
+### Link preview proxying
+
+The relay loads link previews on behalf of the sender - it already sees message content, so it learns nothing new, and unlike the sender its IP is not linked to any identity.
+
+
+## Conclusion
+
+SimpleX Channels enable a publisher to reach an unlimited audience without any infrastructure operator knowing who that audience is. No third party can seize the channel because owners hold the keys and the authoritative state on their own devices - relays only cache and forward. Owner signatures protect content integrity and the trust chain extends to all administrative roles. These properties require a network without participant identifiers - they cannot be added to a system that has them.
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diff --git a/docs/protocol/channels-protocol.md b/docs/protocol/channels-protocol.md
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+Revision 1, 2026-04-28
+
+# SimpleX Channels Protocol
+
+For architecture, design rationale, security properties, and threat model, see [SimpleX Channels Overview](https://simplex.chat/docs/protocol/channels-overview.md).
+
+## Table of contents
+
+- [Protocol](#protocol)
+  - [Channel creation](#channel-creation)
+  - [Relay acceptance](#relay-acceptance)
+  - [Relay addition](#relay-addition)
+  - [Subscriber connection](#subscriber-connection)
+  - [Message signing](#message-signing)
+  - [Message forwarding](#message-forwarding)
+  - [Binary batch format](#binary-batch-format)
+  - [Delivery pipeline](#delivery-pipeline)
+  - [Message deduplication](#message-deduplication)
+  - [Channel-as-sender messages](#channel-as-sender-messages)
+  - [Member support scope](#member-support-scope)
+
+
+## Protocol
+
+This document describes the channel protocol as currently implemented. It builds on the [SimpleX Chat Protocol](https://simplex.chat/docs/protocol/simplex-chat.md), using the same message format and connection model, with extensions for relay-mediated distribution and cryptographic message signing.
+
+### Channel creation
+
+Creating a channel involves generating cryptographic material, creating the channel link, and connecting relay members:
+
+1. **Key generation.** The owner generates an Ed25519 root key pair. The entity ID is computed as `sha256(rootPubKey)`. A separate member key pair is generated for message signing, and an `OwnerAuth` entry is created, signed by the root key.
+
+2. **Link creation.** The owner calls the agent's `prepareConnectionLink` API with the root key pair and entity ID. This returns a prepared link (including a `ConnShortLink` address) without any network calls. The link address is deterministic, derived from the fixed data hash, so it can be embedded in the group profile immediately.
+
+3. **Link data upload.** The owner calls `createConnectionForLink`, which makes a single network call to create the SMP queue and upload the encrypted link data. The link's fixed data contains the root public key and connection request. The mutable user data contains the `OwnerAuth` array, the channel profile (including the entity ID and the link itself), and the initial subscriber count.
+
+4. **Relay invitation.** For each selected relay, the owner sends a contact request containing an `x.grp.relay.inv` message with the channel's short link. The relay retrieves the link data, validates the channel profile, creates its own relay link (with the channel's entity ID in its immutable data), and responds with `x.grp.relay.acpt` containing its relay link.
+
+5. **Link update.** As each relay accepts and provides its relay link, the owner validates that the relay link contains the correct entity ID, then adds the relay link to the channel link's mutable data.
+
+6. **Local record.** The channel is stored on the owner's device with the root private key, member private key, and channel profile. This local record is the authoritative state of the channel.
+
+### Relay acceptance
+
+When a relay receives an invitation to serve a channel, it validates the channel and creates its own relay link. This flow is currently part of channel creation; adding relays to an existing channel is planned but not yet implemented.
+
+1. Owner sends `x.grp.relay.inv` to the relay's contact address. This message includes the relay's member ID and role, the owner's profile, and the channel's short link.
+
+2. Relay receives the invitation and creates a relay request record. A relay request worker processes it asynchronously.
+
+3. The worker retrieves the channel's link data from the SMP server, extracts and validates the channel profile and owner authorization.
+
+4. The relay creates its own contact address link (the relay link) with the channel's entity ID in the immutable fixed data.
+
+5. The relay accepts the owner's connection request, sending its relay link in the acceptance.
+
+6. The owner retrieves the relay link data, validates that the entity ID in the relay link matches the channel's entity ID, and adds the relay link to the channel link's user data.
+
+TODO: Periodic monitoring where the relay retrieves channel link data to verify its relay link is still listed is planned but not yet implemented.
+
+### Relay addition
+
+When the owner adds a relay to an existing channel:
+
+1. **Acceptance.** The new relay accepts the invitation following the [Relay acceptance](#relay-acceptance) flow. The owner promotes the relay to active when the channel link's updated relay list is confirmed.
+
+2. **Announce.** If the channel has at least one subscriber, the owner sends `x.grp.relay.new` (carrying the new relay's short link) to every other currently-connected relay of the channel.
+
+3. **Forward.** Each relay forwards `x.grp.relay.new` to its subscribers. The relay does not create a member record for the announced relay — relays do not connect to other relays of the same channel.
+
+4. **Connect.** On receipt, the subscriber resolves the announced short link and connects to the new relay asynchronously.
+
+The announce is an optimisation. When it does not reach a subscriber — because the channel had no subscribers at announce time, because an older client or relay sits in the path, or because of a transient network failure — the subscriber reaches the same end state on the next channel open via its relay sync against the channel's link data.
+
+### Relay rejection
+
+When a relay operator removes the relay from a channel, the relay marks the channel as rejected and refuses future invitations from the same channel link:
+
+1. **Leave.** The relay operator runs `/leave #channel`. The relay marks the channel as rejected locally, keyed by the channel's short link.
+
+2. **Refuse.** When the owner later sends `x.grp.relay.inv` for the same channel link — typically from a re-invitation — the relay does not accept the invitation as a relay. Instead it replies with `x.grp.relay.reject` over the owner-relay direct contact channel, carrying a rejection reason. The current reason is `rejoin_rejected`; older relays or future reasons fall through to an unknown reason for forward compatibility.
+
+3. **Owner handling.** The owner marks the corresponding relay as rejected and notifies the operator UI. The owner also sets the relay member's status to `GSMemLeft` so the UI treats the rejected relay identically to one that ran `/leave`. The owner's next user-initiated relay addition for the same channel creates a fresh invitation, which the relay rejects again unless the rejection has been cleared.
+
+4. **Clear.** The relay operator runs `/group allow <groupId>` to clear the rejection for the channel. After the next user-initiated relay addition, the relay accepts the invitation and rejoins as a relay.
+
+An older owner client that does not recognise `x.grp.relay.reject` ignores the message and leaves the relay invitation in an invited state indefinitely — the same end state as a relay that does not respond. An older relay binary does not enforce rejection; in mixed-version deployments the operator can re-run `/leave` under the new binary to re-establish rejection.
+
+### Subscriber connection
+
+A subscriber joins a channel through the following flow:
+
+1. **Link retrieval.** The subscriber scans or receives the channel's short link. The client retrieves the link data, which contains the channel profile, owner authorization chain, and list of relay links.
+
+2. **Relay link resolution.** For each relay link listed, the client resolves the `ConnectionRequestUri` from the relay's short link.
+
+3. **Connection.** The client connects to relays - the first synchronously, the rest asynchronously. Each connection sends an `x.member` message with the subscriber's profile (or an incognito profile, created once and shared with all relays), member ID, and member signing key.
+
+4. **Relay acceptance.** Each relay accepts the connection, creates a member record for the subscriber with the configured subscriber role (default `observer`), and sends an `x.grp.link.inv` message with the channel profile and group link invitation data.
+
+5. **Introduction.** The relay introduces the new subscriber to the channel's moderators and owners by sending an `x.grp.mem.new` message. It also sends moderator/owner profiles to the subscriber.
+
+6. **History.** If the channel has history sharing enabled, the relay sends recent cached history to the new subscriber.
+
+The subscriber is functional (can receive messages) as soon as at least one relay connection succeeds. Additional relay connections provide redundancy and cross-relay consistency checking.
+
+### Message signing
+
+Messages that alter the channel's roster, profile, or administrative state are cryptographically signed by the sending owner. Content messages are not signed by default; see [Signing scope](#signing-scope-roster-only-content-optional) for the rationale.
+
+**Which messages require signatures:**
+
+| Message | Description | Signed |
+|---|---|---|
+| `x.grp.del` | Delete channel | Required |
+| `x.grp.info` | Update channel profile | Required |
+| `x.grp.prefs` | Update channel preferences | Required |
+| `x.grp.mem.del` | Remove member | Required |
+| `x.grp.mem.role` | Change member role | Required |
+| `x.grp.mem.restrict` | Restrict member | Required |
+| `x.grp.relay.new` | Announce new relay to subscribers | Required |
+| `x.grp.leave` | Leave channel | Required (unverified allowed between subscribers) |
+| `x.info` | Update member profile | Required (unverified allowed between subscribers) |
+| `x.msg.new` | Content message | Not signed |
+| `x.msg.update` | Edit message | Not signed |
+| `x.msg.del` | Delete message | Not signed |
+
+**Signing process:**
+
+The signing context binds the signature to a specific channel and sender:
+
+```
+bindingPrefix = smpEncode(CBGroup) <> smpEncode(publicGroupId, memberId)
+signedBytes   = bindingPrefix <> messageBody
+signature     = Ed25519.sign(memberPrivKey, signedBytes)
+```
+
+The binding prefix includes the chat binding tag (`"G"` for group), the channel's entity ID, and the sender's member ID. This prevents cross-channel and cross-member replay attacks - a signature valid in one channel cannot be reused in another.
+
+**Verification process:**
+
+When a subscriber receives a signed message:
+
+1. The signature is present: reconstruct the binding prefix from the channel's stored entity ID and the sender's member ID. Verify all signatures against the sender's stored public key. If all verify, the message is accepted as verified.
+
+2. The signature is present but the sender's key is unknown: the message is accepted as signed-but-unverified only if the event does not require a signature. For `x.grp.leave` and `x.info` between subscribers whose keys haven't been exchanged yet, unverified signatures are permitted as a temporary measure.
+
+3. No signature is present: the message is accepted only if the event does not require a signature (i.e., the channel does not use relays, or the event is a content message).
+
+If verification fails for a message that requires a signature, the message is rejected and a bad signature event is shown to the user.
+
+### Message forwarding
+
+Content originates on the owner's device and flows through relays to subscribers. The forwarding mechanism preserves the original message bytes, including any signature, without re-encoding:
+
+**Owner to Relay:** The owner sends messages directly to each relay over their SMP connection. Messages are encoded in binary batch format.
+
+**Relay processing:** When a relay receives a message from an owner, it:
+
+1. Parses and processes the message locally (updating its cached state, e.g. for roster changes).
+2. If the relay is configured to forward for this channel, creates a **delivery task** for each message that should be forwarded to subscribers. The task records the message ID, the sender's member ID, the broker timestamp, and whether the message was sent as the channel (not attributed to a specific owner).
+3. The delivery task is persisted to the database for delivery reliability - ensuring forwarding can resume after a relay crash.
+
+**Relay to Subscribers:** A delivery task worker reads pending tasks, batches them into delivery jobs, and a delivery job worker sends each job to subscribers in paginated batches (using a cursor over group member IDs).
+
+For forwarded messages from subscribers to owners (e.g. support scope messages), the relay wraps the message in a forwarding envelope:
+
+```
+forwardEnvelope = ">" <> smpEncode(GrpMsgForward) <> encodeBatchElement(signedMsg, msgBody)
+```
+
+This preserves the original message's signature bytes verbatim.
+
+### Binary batch format
+
+Channels use a binary batch format that preserves exact message bytes for signature verification. This is distinct from the JSON array batching used by regular groups.
+
+```abnf
+binaryBatch    = %s"=" elementCount *batchElement
+elementCount   = 1*1 OCTET                    ; 1-255 elements
+batchElement   = elementLen elementBody
+elementLen     = 2*2 OCTET                    ; 16-bit big-endian length
+
+elementBody    = signedElement / forwardElement / plainElement / fileElement
+
+signedElement  = %s"/" chatBinding sigCount *msgSignature jsonBody
+forwardElement = %s">" grpMsgForward (signedElement / plainElement)
+plainElement   = %s"{" *OCTET                 ; JSON message body
+fileElement    = %s"F" *OCTET                 ; binary file chunk
+
+chatBinding    = 1*1 OCTET                    ; "G" (group), "D" (direct), "C" (channel)
+sigCount       = 1*1 OCTET                    ; number of signatures (1-255)
+msgSignature   = keyRef sigBytes
+keyRef         = %s"M"                        ; member key reference
+sigBytes       = 64*64 OCTET                  ; Ed25519 signature
+
+grpMsgForward  = fwdSender brokerTs
+fwdSender      = memberFwd / channelFwd
+memberFwd      = %s"M" memberId memberName    ; attributed to specific member
+channelFwd     = %s"C"                        ; attributed to channel as sender
+brokerTs       = 8*8 OCTET                    ; UTC system time
+```
+
+The parser (`parseChatMessages`) dispatches on the first byte:
+
+- `'='` -> binary batch (new format, used by channels)
+- `'X'` -> compressed (decompress, then re-parse)
+- `'['` -> JSON array (legacy group format)
+- `'{'` -> single JSON message
+
+Forward elements contain the original message bytes verbatim. The relay does not re-encode the inner message. This is what makes signature verification possible after forwarding: the exact bytes that were signed by the owner are preserved through the relay.
+
+Nested forwarding (`>` inside `>`) is explicitly rejected by the parser.
+
+### Delivery pipeline
+
+The relay's delivery pipeline has two stages, both backed by persistent database tables for delivery reliability (not for authoritative storage - the relay's database is a delivery queue, not a content database):
+
+**Stage 1: Delivery tasks.** When the relay receives a message from an owner that should be forwarded, it creates a `delivery_task` record:
+
+```
+delivery_task:
+  group_id, worker_scope, job_scope,
+  sender_group_member_id, message_id,
+  message_from_channel (bool),
+  task_status (new -> processed)
+```
+
+A **task worker** (one per group per scope) reads pending tasks, batches multiple tasks into a single binary batch body, and creates a delivery job.
+
+**Stage 2: Delivery jobs.** A delivery job contains the pre-encoded batch body and a cursor for paginated delivery:
+
+```
+delivery_job:
+  group_id, worker_scope, job_scope,
+  body (pre-encoded binary batch),
+  cursor_group_member_id,
+  job_status (pending -> complete)
+```
+
+A **job worker** reads the body and delivers it to subscribers in paginated batches. For each page, it loads a bucket of subscribers by cursor position, sends the body to all of them, advances the cursor, and continues until all subscribers have been served. This avoids loading all subscribers into memory at once.
+
+For subsequent subscribers in a batch, the agent uses a value reference to the first subscriber's message body, avoiding redundant data transmission to the SMP server.
+
+### Message deduplication
+
+When multiple relays serve the same channel, each subscriber receives the same message from each relay independently. Deduplication is performed at the subscriber's client level using the message's shared message ID:
+
+- When saving a received message, the client checks whether a message with the same shared ID already exists for this group.
+- If a duplicate is found, the message is silently dropped (in channels with relays).
+- In non-relay groups, duplicate detection triggers a `x.grp.mem.con` notification to the forwarding member.
+
+This is essentially cache coherence verification - comparing what was received from one cache node against another. TODO: Currently, deduplication only detects the presence of duplicates. The protocol design includes provisions for detecting differences between relay-delivered copies of the same message (hash comparison, UI indicators for discrepancies). This is described in the [channels forwarding RFC](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2025-08-11-channels-forwarding.md) and is not yet implemented.
+
+### Channel-as-sender messages
+
+Owners can send messages attributed to the channel rather than to themselves. When `asGroup = True` is set in the message container, the relay forwards the message with a channel-as-sender tag instead of attributing it to a specific member. On the subscriber side, such messages are displayed as coming from the channel (using the channel's profile image and name) rather than from a specific owner.
+
+This will be useful for channels with multiple owners (not yet implemented at application level) where the identity of the specific sender should not be visible to subscribers. The relay must respect this directive; ignoring it and revealing the sending owner's identity is a threat vector (detectable out-of-band by members communicating with the owner).
+
+The forwarding binding prefix for channel-as-sender messages uses `CBChannel` instead of `CBGroup`, and includes only the channel's entity ID (not the sender's member ID):
+
+```
+channelBinding = smpEncode(CBChannel) <> smpEncode(publicGroupId)
+```
+
+### Member support scope
+
+Channels support a **member support scope** - a private side-channel between a subscriber and the channel's moderators/owners. Messages sent in the support scope are delivered only to moderators and the scoped subscriber, not to all subscribers.
+
+A support-scoped message includes the target member's ID. The delivery pipeline uses a separate job scope for support messages, loading only the scoped member and moderators rather than all subscribers.
+
+Support scope messages are visible only to the subscriber who initiated the support conversation and to the channel's moderators. Other subscribers cannot see them. This allows subscribers to report issues, appeal moderation decisions, or communicate with administrators without revealing their identity to other subscribers.
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+<link rel="alternate" type="text/markdown" href="/docs/protocol/names-overview.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
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+Revision 1, 2026-07-14
+
+# SimpleX Public Names for Channels and Businesses
+
+## Table of contents
+
+- [Introduction](#introduction)
+  - [Names](#names)
+  - [Use cases](#use-cases)
+  - [On-chain registry](#on-chain-registry)
+  - [Privacy considerations](#privacy-considerations)
+- [Architecture](#architecture)
+  - [Names and records](#names-and-records)
+  - [Resolution](#resolution)
+  - [Private decentralized RPC layer](#private-decentralized-rpc-layer)
+  - [Claiming and verification](#claiming-and-verification)
+- [Differences from ENS](#differences-from-ens)
+- [Security](#security)
+  - [Design objectives](#design-objectives)
+  - [Threat model](#threat-model)
+  - [Current gaps](#current-gaps)
+- [Future work](#future-work)
+- [Conclusion](#conclusion)
+
+
+## Introduction
+
+The SimpleX network provides communication without user identifiers - people connect by exchanging links out of band. This protects private communication, but public entities - channels and businesses - need to be discoverable. Today this requires distributing a long link, which is impossible to remember and can be deleted by the router that hosts it. SimpleX public names provide memorability and ease of connection without adding user identifiers.
+
+### Names
+
+A SimpleX name is a human-readable name, registered on a public blockchain, that resolves to SimpleX links: `#example.simplex` opens a channel (for the `.simplex` namespace, the short variant `#example` can also be used for channel names) and `@example.simplex` connects to a contact or business address. One name can include both links - a business can publish `@example.simplex` for customer conversations and `#example.simplex` for its announcement channel from a single registration. Names support subnames (`support.example.simplex`). A separate test namespace (`.testing`) is deployed for early adopters before the main namespace launches.
+
+A name is not an account and not an identity. It is a record that maps a human-readable string to the links a channel or business already has, controlled by a cryptographic key that only its owner holds. The network does not use or require names; they are a discovery layer on top of it, described in this document.
+
+This document covers the naming layer built for [SimpleX Channels](https://simplex.chat/docs/protocol/channels-overview.md) and the [SimpleX network](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md). For the user-facing registration steps see [Registering a SimpleX name](https://simplex.chat/docs/guide/register-simplex-name.md); for protocol-level details see the resolver commands in the [SMP protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/simplex-messaging.md).
+
+### Use cases
+
+Names are intended for entities that are already public:
+
+- **Channels.** A channel reachable as `#example` can be easily shared in many ways - conversation, print, social media, and messages. If the channel's link is removed or blocked, the owner can point the name to a new link, and the channel remains reachable via the same name.
+
+- **Businesses and organizations.** A business address reachable as `@example.simplex` gives customers a way to start a conversation without scanning a QR code or trusting a link from a search result.
+
+- **Creators and public figures.** Anyone publishing to an audience can be reachable by name while their audience remains private.
+
+Names are opt-in and are only useful for public entities. Private users do not need them. Even when an entity uses a name, the network cannot track who connects to it - the communication graph remains private.
+
+### On-chain registry
+
+Names must be globally unique, so they require a shared registry. Every conventional registry design places names under an operator's control:
+
+- **A platform registry** (usernames in messaging apps) is owned by the operator: names can be revoked, impersonated, or reassigned, and the platform sees who looks up whom.
+
+- **DNS** is subject to domain seizure at the registrar and registry level, and requires registrant records.
+
+A record on a public blockchain has no operator: only the holder of the registration key can change what a name points to, and no authority can delete it. This mitigates censorship at these levels:
+
+- **SMP routers.** The router that hosts a link can delete it, and the link stops working for everyone who saved it. A name is not affected: the owner points it to a new link on a different router, and clients connect via the same name as before.
+
+- **Centralized registries.** An on-chain record cannot be revoked, because there is no intermediary.
+
+### Privacy considerations
+
+Names do not:
+
+- **Identify users.** There is no user directory, no requirement to register a name, and nothing links a name to the people who connect to it.
+
+- **Put communication on the chain.** The blockchain stores only the mapping from a name to links and optional public profile fields. Messages, membership, and channel content are never stored on the blockchain.
+
+- **Certify identity.** A verified name proves that the name's owner controls the address it points to - not who the owner is. It is the same trust model as a domain name.
+
+- **Replace links.** Links remain the primary and the more private connection mechanism, since resolving a name reveals interest in it to one resolver operator. Names are for public entities that choose to be contactable more easily.
+
+
+## Architecture
+
+### Names and records
+
+Names are lowercase labels of ASCII letters, digits, and single hyphens, forming domains under the `.simplex` top-level name (`example.simplex`, `my-channel.simplex`), with `.simplex` implied when omitted for channels: `#example` is interpreted as `#example.simplex`. The restricted alphabet prevents homograph attacks: visually identical names from mixed scripts cannot exist as distinct records.
+
+A name's on-chain record stores:
+
+- **Channel links and contact links** - each an ordered list, primary first. Multiple links give redundancy across SMP routers: clients try them in order, so the name remains usable if one router becomes unavailable. Client support for this redundancy is planned for the `.simplex` namespace launch.
+- **Optional profile fields** - a display name, website, location.
+- **Optional donation addresses** (Monero, Bitcoin, Ethereum, etc.) that apps can show to channel subscribers.
+
+Registration is a two-transaction commit-reveal process from the owner's wallet: the first transaction records only a hash, so an observer of the pending registration cannot see the name and front-run it; the second transaction reveals the name and completes the registration. The name is held as an ordinary token in the owner's wallet and is renewable and transferable. Subnames are created by the name's owner, are transferred together with the name, and cannot be separately sold - the same ownership model as DNS subdomains.
+
+### Resolution
+
+Connecting by name is two independent resolutions:
+
+1. **Name to link.** The client queries the on-chain record through the SimpleX network (next section) and obtains the channel or contact link.
+
+2. **Link to connection.** The link resolves through the existing SimpleX short-link protocol: the client retrieves the link's immutable data - cryptographically bound to the link's owner keys - and the entity's profile, and connects.
+
+The second step is unchanged from connecting by link. A name adds discoverability on top of the link protocol; it does not weaken the link's own verification, and everything a client checks when joining by link is still checked when joining by name.
+
+### Private decentralized RPC layer
+
+Reading blockchain state normally requires querying an RPC service, and in practice almost all applications - including wallets and name services - use a handful of centralized API providers. Those providers see every query, the account it concerns, and the querier's IP address, and can censor or falsify responses. Resolving names through such a provider would reveal every lookup and the client's IP address to a third party.
+
+SimpleX resolves names through the network itself. Operators can enable a *names role* on their SMP routers: a names router runs its own resolver process and its own Ethereum node, holding a full copy of the relevant chain state - operators must not share this backend with other operators. The lookup is a protocol command sent as ordinary SimpleX traffic:
+
+1. The client selects a names router among its configured servers and sends the lookup *through an SMP proxy operated by a different operator*, encrypted so the proxy cannot read it.
+2. The proxy forwards the lookup without access to its content; the names router responds from its local chain state.
+
+```mermaid
+sequenceDiagram
+    participant C as Client
+    participant P as SMP proxy<br/>(operator A)
+    participant N as Names router<br/>(operator B)
+    participant E as Ethereum node<br/>(operator B, local)
+
+    C->>P: lookup, encrypted for the names router
+    note over P: sees the client,<br/>not the name
+    P->>N: forwarded lookup
+    note over N: sees the name,<br/>not the client
+    N->>E: read name record (eth_call)
+    E-->>N: name record
+    N-->>P: response, encrypted for the client
+    P-->>C: name record: channel and contact links
+```
+
+The result is a knowledge split with no single observer: the proxy sees which client communicates with a names router, but not the name; the names router sees the name, but not which client sent the query - no client address, session, or identity. A passive network observer sees fixed-size encrypted blocks indistinguishable from other traffic. Clients also keep the set of parties that see a lookup minimal: a query is sent to one names router, and after an authoritative response the client does not repeat the name to other servers.
+
+This layer is not specific to names. Private access to blockchain state via independent operators is a network capability that can be used in other contexts in the future.
+
+### Claiming and verification
+
+A name is trustworthy when:
+
+1. **The on-chain record points to the link.** Only the name owner's wallet key can set this.
+2. **The link's profile claims the name.** Only the link owner's keys can publish this, and the claim is signed by the link's owner key, binding it to that specific link.
+
+For name resolution to succeed, SimpleX clients require both to be true. This mutual binding prevents abuse, such as:
+
+- Registering a name that points to someone else's address. The profile does not claim the name, so clients refuse to connect to it.
+- Claiming a name in a profile without owning it. The on-chain record does not point to that profile's address, so the claim fails verification.
+
+Apps display the outcome next to the name - verified (the record and the claim match), failed, or not yet verified - and can re-verify on demand or automatically. Verification is a fresh resolution through the private RPC layer, so it reflects the current on-chain state.
+
+Names are used only to establish connections, not to deliver messages. Once connected, a contact or channel subscription is an ordinary SimpleX connection, independent of the name. A name expiring or being transferred affects future connections only; existing conversations and subscriptions are not affected.
+
+
+## Differences from ENS
+
+The on-chain layer is the SimpleX Name Service (SNS), a fork of the [Ethereum Name Service](https://ens.domains) (ENS). ENS is the most widely used decentralized naming system, and SNS retains its core design: the registry and resolver contracts, commit-reveal registration, and expiry-based ownership.
+
+Each top-level name (`.testing`, `.simplex`) is an independent deployment of the same contracts:
+
+```mermaid
+flowchart TD
+    CT["Controller<br/>commit-reveal registration"]
+    RG["Registrar<br/>name tokens, on-chain name index"]
+    PR["Resolver<br/>simplex.contact / simplex.channel records"]
+    R["Registry<br/>owner and resolver of every name"]
+    MR["Metadata renderer<br/>token metadata as on-chain JSON + SVG"]
+    SR["Subname registrar<br/>creates and indexes subnames"]
+
+    CT -->|registers names| RG
+    CT -->|writes records| PR
+    RG -->|sets name ownership| R
+    RG -->|renders tokens| MR
+    SR -->|owns subname nodes| R
+```
+
+ENS, however, is not fully decentralized in use. Its applications depend on two off-chain services: an indexer (the subgraph) for queries such as listing the names held by an address (without it the ENS app is unusable), and a hosted metadata service to render name tokens in wallets. SNS removes both dependencies, and simplifies the ownership model:
+
+1. **No indexer.** The SNS contracts index names on-chain: reverse lookup from an address to the names it holds, from a token to its plaintext label, and from a name to its subnames are all direct contract reads. Every view in the SNS web app (currently, the app for test names is https://testing-names.simplex.chat) - the list of owned names, their subnames, and each name's records - is served by plain `eth_call`s against an Ethereum RPC.
+
+2. **Fully on-chain tokens.** A name's token metadata and image are generated by the contract as inline JSON and SVG. There is no metadata server; wallets render the name from chain data alone.
+
+3. **No name wrapper, no separate subname ownership.** ENS's wrapper system lets subnames be split off and owned independently, at the cost of a second token standard and a complex permission system. SNS subnames are owned together with the name and are transferred with it (the DNS model), removing the need for the wrapper.
+
+Resolution also differs. ENS names are resolved by applications through their RPC providers, so lookups are as centralized and observable as the provider. SNS records are read through the private RPC layer described above: many independent operators hold the chain state, and no single party sees who resolves which name.
+
+The result is a naming system with no off-chain services: registration, ownership, enumeration, rendering, and resolution are all either on-chain or served by the SimpleX network itself.
+
+The current implementation uses a web app for registration, which accesses the chain via a centralized RPC provider. We plan to add name purchases to the SimpleX apps, using the same decentralized blockchain access that is already used for name resolution.
+
+
+## Security
+
+### Design objectives
+
+1. **Non-custodial.** Only the holder of the name's key can change or transfer the record; there is no registrar, operator, or intermediary with override authority.
+2. **No infrastructure censorship.** A name does not depend on any single router: the links it points to can be replaced without changing the name, and resolution uses chain state held by many independent operators.
+3. **Impersonation resistance.** A name is shown as verified only when the on-chain record and the signed claim in the link's profile match.
+4. **Lookup privacy.** No single party observes both the user and the name being resolved.
+5. **Availability.** A record can list multiple links across routers, and any names-capable router of the user's choosing can respond to a lookup.
+
+### Threat model
+
+This threat model assumes the [SimpleX network threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/security.md) and the [channels threat model](https://simplex.chat/docs/protocol/channels-overview.md#threat-model), and addresses the naming layer.
+
+**A compromised names router (or its chain backend)**
+
+*can:*
+
+- Deny that a name exists, or serve a stale record, to the clients that query it. Detectable by resolving through a different operator's router.
+- Serve a false record - effective only against a client that queries this router *and* only if the false record's target cooperates by claiming the name, since the claim check runs against the attacker-supplied record. Resolver agreement across operators ([future work](#future-work)) makes this require collusion of the queried operators.
+- Observe which names are looked up, and how often.
+
+*cannot:*
+
+- Learn who is looking up a name - it never sees the client's address, session, or identity.
+- Alter the on-chain record, or affect clients resolving through other routers.
+- Affect existing connections - they do not depend on names.
+
+**An SMP proxy forwarding lookups**
+
+*can:*
+
+- See that a client communicates with a names router (which is an ordinary SMP router).
+
+*cannot:*
+
+- See that a request forwarded to a destination router is a name resolution request.
+- See the name being looked up, or the response - both are encrypted between client and names router.
+
+**An impersonator**
+
+*can:*
+
+- Register a confusingly similar name. The restricted alphabet keeps such names visibly different - homographs are not possible.
+
+*cannot:*
+
+- Register a visually identical variant of an existing name using other scripts or invisible characters.
+- Achieve verified status for a name pointing to someone else's address, or for an address whose name points elsewhere.
+
+**Compromise of the owner's wallet key**
+
+An attacker holding the registration key can repoint or transfer the name. New lookups then resolve to the attacker's links; the owner's profile claim no longer matches the record, so clients verifying the owner's profile see a failure. Existing connections are unaffected. Protecting the registration key is the owner's responsibility, the same as protecting the channel's own keys. An expired name that is not renewed can also be registered by someone else, so the key must be backed up and the name renewed on time.
+
+**A passive network observer**
+
+*can:*
+
+- See SimpleX traffic between clients and routers.
+
+*cannot:*
+
+- Distinguish name lookups from any other traffic, or learn which names anyone resolves. Inherited from SMP transport.
+
+### Current gaps
+
+1. **Single-resolver lookups.** A client currently accepts the response of one names router per lookup. Cross-checking two operators' resolvers is designed but not implemented - see below.
+2. **No state proofs.** The names router is trusted to report chain state correctly; responses do not yet include proofs verifiable against a chain header.
+3. **Self-hosted routers.** All pre-configured routers support name resolution, but most self-hosted routers do not support it yet. Name resolution requires at least one configured server with the names role.
+
+
+## Future work
+
+- **Two-resolver agreement.** Resolve each name through two independent operators via two different proxies and compare the responses: a match is trusted; a mismatch is shown as a warning and the record is not used. This removes the single-resolver trust noted above and makes record substitution require cross-operator collusion.
+
+- **State proofs.** Responses including Merkle proofs of Ethereum state, verified by the client - removing the need to trust the resolver, with or without agreement.
+
+- **Main namespace launch.** The `.testing` namespace is deployed for early adopters; the `.simplex` namespace launches after the testing period.
+
+- **Registration via an app.** Registration currently requires an on-chain transaction from a wallet.
+
+- **DNS-based names.** The client already parses arbitrary domains (`example.com`) as web links. In the future, it will be possible to register owned domains in the SNS contract to use them as channel and contact names (`#example.com` and `@example.com`).
+
+
+## Conclusion
+
+SimpleX names give channels and businesses memorable addresses that do not depend on any single server and cannot be revoked by a platform or registrar. Resolution runs through the SimpleX network, so no party observes who looks up which name. The naming system is fully decentralized on-chain, with no indexer or metadata service, and access to it is private, with no RPC provider observing requests. Names are optional and used only by public entities; private communication in SimpleX remains identifier-free.
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+Revision 2, 2024-06-24
+
+Evgeny Poberezkin
+
+# SimpleX Chat Protocol
+
+## Abstract
+
+SimpleX Chat Protocol is a protocol used by SimpleX Chat clients to exchange messages. This protocol relies on lower level SimpleX protocols - SimpleX Messaging Protocol (SMP) and SimpleX Messaging Agent protocol. SimpleX Chat Protocol describes the format of messages and the client operations that should be performed when receiving such messages.
+
+## Scope
+
+The scope of SimpleX Chat Protocol is application level messages, both for chat functionality, related to the conversations between the clients, and extensible for any other application functions. Currently supported chat functions:
+
+- direct and group messages,
+- message replies (quoting), message editing, forwarded messages and message deletions,
+- message attachments: images, videos, voice messages and files,
+- creating and managing chat groups,
+- invitation and signalling for audio/video WebRTC calls.
+
+## General message format
+
+SimpleX Chat protocol supports these message formats:
+
+- JSON-based format for chat and application messages.
+- compressed format for adapting larger messages to reduced size of message envelope, caused by addition of PQ encryption keys to SMP agent message envelope.
+- binary format for sending files or any other binary data.
+
+JSON-based message format supports batching inside a single container message, by encoding list of messages as JSON array.
+
+Current implementation of chat protocol in SimpleX Chat uses SimpleX File Transfer Protocol (XFTP) for file transfer, with passing file description as chat protocol messages, instead passing files in binary format via SMP connections.
+
+### JSON format for chat and application messages
+
+This document uses JTD schemas [RFC 8927](https://www.rfc-editor.org/rfc/rfc8927.html) to define the properties of chat messages, with some additional restrictions on message properties included in metadata member of JTD schemas. In case of any contradiction between JSON examples and JTD schema the latter MUST be considered correct.
+
+Whitespace is used in JSON examples for readability, SimpleX Chat Protocol clients MUST avoid using whitespace when encoding JSON messages.
+
+General message format is defined by this JTD schema:
+
+```JSON
+{
+  "properties": {
+    "event": {
+      "type": "string"
+    },
+    "msgId": {
+      "type": "string",
+      "metadata": {
+        "format": "base64url-encoded 12 bytes random message ID"
+      }
+    },
+    "params": {
+      "optionalProperties": {}
+    }
+  }
+}
+```
+
+For example, this message defines a simple text message `"hello!"`:
+
+```JSON
+{
+  "event": "x.msg.new",
+  "msgId": "abcd",
+  "params": {
+    "content": {
+      "type": "text",
+      "text": "hello!"
+    }
+  }
+}
+```
+
+`msgId` property is a 12 bytes base64url-encoded random message ID that the clients can use to reference the message in the future, e.g. when editing, quoting or deleting it.
+
+`event` property is the type of the message that defines the semantics of the message and the allowed format of `params` property.
+
+`params` property includes message data, depending on `event`, as defined below and in [JTD schema](simplex-chat.schema.json).
+
+### Compressed format
+
+The syntax of compressed message is defined by the following ABNF notation:
+
+```abnf
+compressedMessage = %s"X" 1*15780 OCTET; compressed message data
+```
+
+Compressed message is required to fit into 15602 bytes, or into 13380 bytes for a connection with PQ encryption, accounting for agent overhead (see Protocol's maxEncodedMsgLength and maxEncodedMsgLengthPQ).
+
+The actual JSON message is required to fit into 15610 bytes, accounting for group message forwarding (x.grp.msg.forward) overhead (see Protocol's maxEncodedMsgLength).
+
+### Binary format for sending files
+
+> Note: Planned to be deprecated. No longer used for file transfer in SimpleX Chat implementation of chat protocol.
+
+SimpleX Chat clients use separate connections to send files using a binary format. File chunk size send in each message MUST NOT be bigger than 15,780 bytes to fit into 16kb (16384 bytes) transport block.
+
+The syntax of each message used to send files is defined by the following ABNF notation:
+
+```abnf
+fileMessage = fileChunk / cancelFile
+fileChunk = %s"F" chunkNo chunk
+cancelFile = %s"C"
+chunkNo = 4*4 OCTET ; 32bit word sequential chunk number, starting from 1, in network byte order
+chunk = 1*15780 OCTET ; file data, up to 15,780 bytes
+```
+
+The first chunk number MUST be 1.
+
+## Messages and chat items
+
+While users usually use the term "message" to refer to the objects presented in the conversation, the expected functionality of these objects makes it a wrong term. "Messages" are supposed to be immutable; they cannot be modified or deleted once sent. The objects in the conversation are expected to be mutable. This document and implementation use the term "chat item" to refer to these objects to differentiate them from the messages sent between the clients.
+
+## Supported JSON message types and SimpleX Chat sub-protocols
+
+Message types are sent as a string in `event` property of JSON messages. General syntax of event string is defined by this ABNF:
+
+```abnf
+event = namespace "." subprotocol *("." eventWord)
+namespace = eventWord ; 1-letter recommended
+subprotocol = eventWord
+eventWord = 1* ALPHA
+```
+
+All SimpleX Chat Protocol messages related to chat functions are defined in `x` namespace.
+
+Sub-protocol is a group of messages for related message functions - e.g. sending files, managing groups or negotiating WebRTC calls.
+
+SimpleX Chat Protocol supports the following message types passed in `event` property:
+
+- `x.contact` - contact profile and additional data sent as part of contact request to a long-term contact address.
+- `x.info*` - messages to send, update and de-duplicate contact profiles.
+- `x.msg.*` - messages to create, update and delete content chat items.
+- `x.msg.file.descr` - message to transfer XFTP file description.
+- `x.file.*` - messages to accept and cancel sending files (see files sub-protocol).
+- `x.direct.del` - message to notify about contact deletion.
+- `x.grp.*` - messages used to manage groups and group members (see group sub-protocol).
+- `x.call.*` - messages to invite to WebRTC calls and send signalling messages.
+- `x.ok` - message sent during connection handshake.
+
+JTD schema defining messages for all chat functions is available in [this file](simplex-chat.schema.json) – please refer to this document for all properties of the message `params`.
+
+## x.contact - sending connection request
+
+The message is sent as part of the connection request to the long-term user address. `contactReqId` property is used to identify a duplicate contact request - the receiving client MAY put repeated request on top of the list in the UI.
+
+## Sub-protocol for contact profile
+
+### x.info - contact profile
+
+This message is sent by both sides of the connection during the connection handshake, and can be sent later as well when contact profile is updated.
+
+### Probing for duplicate contacts
+
+As there are no globally unique user identifiers, when the contact a user is already connected to is added to the group by some other group member, this contact will be added to user's list of contacts as a new contact. To allow merging such contacts, "a probe" (random base64url-encoded 32 bytes) SHOULD be sent to all new members as part of `x.info.probe` message and, in case there is a contact with the same profile, the hash of the probe MAY be sent to it as part of `x.info.probe.check` message. In case both the new member and the existing contact are the same user (they would receive both the probe and its hash), the contact would send back the original probe as part of `x.info.probe.ok` message via the previously existing contact connection – proving to the sender that this new member and the existing contact are the same user, in which case the sender SHOULD merge these two contacts.
+
+Sending clients MAY disable this functionality, and receiving clients MAY ignore probe messages.
+
+If the sending client uses `x.info.probe` messages, it MUST send them to all new members, rather than only when there is a matching contact profile. This is to avoid leaking information that the matching contact profile exists.
+
+## Sub-protocol for content messages
+
+### x.msg.new - a new content message
+
+When chat clients receive or send this message, they MUST create a new chat item in the conversation. Top level `msgId` property is defined to allow referencing this chat item or message in the future, e.g. to delete, update or quote chat item, or to accept file.
+
+This message uses `params` property of the message as content message container, without any top level properties for the container. Message container (`params`) includes message `content` property, an optional "invitation" to receive file or image attachment in `file` property (that is interpreted depending on message content type) and optional indication whether this message is forwarded (`"forward": true` property of container) or sent in reply to other message (`"quote": {<quoted message>}`). See `/definition/msgContainer` in [JTD schema](simplex-chat.schema.json) for message container format.
+
+Message content can be one of four types:
+
+- `text` - no file attachment is expected for this format, `text` property MUST be non-empty.
+- `file` - attached file is required, `text` property MAY be empty.
+- `image` - attached file is required, `text` property MAY be empty.
+- `video` - attached file is required, `text` property MAY be empty.
+- `voice` - attached file is required, `text` property MAY be empty.
+- `link` - no file attachment is expected, `text` property MUST be non-empty. `preview` property contains information about link preview.
+
+See `/definition/msgContent` in [JTD schema](simplex-chat.schema.json) for message container format.
+
+### x.msg.update - update of the previously sent message
+
+This message is used to update previously created chat item. Its `params` property contains `msgId` of the previously sent message that this one is updating and `content` with the message content that the clients must use to replace the content of the original chat item.
+
+If the referenced message does not exist, the clients MUST create a new chat item with the ID of the referenced message. If the referenced message is not a content message, the clients MUST ignore this message.
+
+### x.msg.del - request to delete previously sent message
+
+This message is used to delete previously sent chat items. Receiving clients MUST implement it as soft-delete, replacing the original chat item with a special chat item indicating that "message is deleted" that can be fully deleted by the user. If the referenced message does not exist or was sent by the different user than the one sending `x.msg.del`, the receiving clients MUST ignore this message. Clients are also RECOMMENDED to limit the time during which message deletion is allowed, both for senders and for the recipients.
+
+## Sub-protocol for sending and receiving files
+
+When content message `x.msg.new` contains file attachment (the invitation to receive the file), this sub-protocol is used to accept this file or to notify the recipient that sending the file was cancelled.
+
+File attachment can optionally include connection address to receive the file - clients MUST include it when sending files to direct connections, and MUST NOT include it when sending file attachment to the group (as different members would need different connections to receive the file).
+
+`x.file.acpt` message is used to accept the file in case when file connection address was included in the message (that is the case when the file invitation was sent in direct message). It is sent as part of file connection handshake via file connection, that is why this message contains no reference to the file - the used connection provides sufficient context for the sender.
+
+`x.file.acpt.inv` message is used to accept the file in group conversations, it includes the connection address. It is sent in the same connection where the file was offered and must reference the original message.
+
+`x.file.cancel` message is sent to notify the recipient that sending of the file was cancelled. It is sent in response to accepting the file with `x.file.acpt.inv` message. It is sent in the same connection where the file was offered.
+
+`x.msg.file.descr` message is used to send XFTP file description. File descriptions that don't fit into a single chat protocol message are sent in parts, with messages including part number (`fileDescrPartNo`) and description completion marker (`fileDescrComplete`). Recipient client accumulates description parts and starts file download upon completing file description.
+
+## Sub-protocol for chat groups
+
+### Decentralized design for chat groups
+
+SimpleX Chat groups are fully decentralized and do not have any globally unique group identifiers - they are only defined on client devices as a group profile and a set of bi-directional SimpleX connections with other group members. When a new member accepts group invitation or joins via group link, the inviting member introduces a new member to all existing members and forwards the connection addresses so that they can establish direct and group member connections.
+
+There is a possibility of the attack here: as the introducing member forwards the addresses, they can substitute them with other addresses, performing MITM attack on the communication between existing and introduced members - this is similar to the communication operator being able to perform MITM on any connection between the users. To mitigate this attack this group sub-protocol will be extended to allow validating security of the connection by sending connection verification out-of-band.
+
+Clients are RECOMMENDED to indicate in the UI whether the connection to a group member or contact was made directly or via another user.
+
+Each member in the group is identified by a group-wide unique identifier used by all members in the group. This is to allow referencing members in the messages and to allow group message integrity validation.
+
+The diagram below shows the sequence of messages sent between the users' clients to add the new member to the group.
+
+While introduced members establish connection inside group, inviting member forwards messages between them by sending `x.grp.msg.forward` messages. When introduced members finalize connection, they notify inviting member to stop forwarding via `x.grp.mem.con` message.
+
+![Adding member to the group](diagrams/group.svg)
+
+### Member roles
+
+Currently members can have one of four roles - `owner`, `admin`, `member` and `observer`. The user that created the group is self-assigned owner role, the new members are assigned role by the member who adds them - only `owner` and `admin` members can add new members; only `owner` members can add members with `owner` role. `Observer` members only receive messages and aren't allowed to send messages.
+
+### Messages to manage groups and add members
+
+`x.grp.inv` message is sent to invite contact to the group via contact's direct connection and includes group member connection address. This message MUST only be sent by members with `admin` or `owner` role. Optional `groupLinkId` is included when this message is sent to contacts connected via the user's group link. This identifier is a random byte sequence, with no global or even local uniqueness - it is only used for the user's invitations to a given group to provide confirmation to the contact that the group invitation is for the same group the contact was connecting to via the group link, so that the invitation can be automatically accepted by the contact - the contact compares it with the group link id contained in the group link uri's data field.
+
+`x.grp.acpt` message is sent as part of group member connection handshake, only to the inviting user.
+
+`x.grp.link.inv` message is sent as part of connection handshake to member joining via group link, and contains group profile and initial information about inviting and joining member.
+
+`x.grp.link.mem` message is sent as part of connection handshake to member joining via group link, and contains remaining information about inviting member.
+
+`x.grp.mem.new` message is sent by the inviting user to all connected members (and scheduled as pending to all announced but not yet connected members) to announce a new member to the existing members. This message MUST only be sent by members with `admin` or `owner` role. Receiving clients MUST ignore this message if it is received from member with `member` role.
+
+`x.grp.mem.intro` messages are sent by the inviting user to the invited member, via their group member connection, one message for each existing member. When this message is sent by any other member than the one who invited the recipient it MUST be ignored.
+
+`x.grp.mem.inv` messages are sent by the invited user to the inviting user, one message for each existing member previously introduced with `x.grp.mem.intro` message. When this message is sent by any other member than the one who was invited by the recipient it MUST be ignored.
+
+`x.grp.mem.fwd` message is used by the inviting user to forward the invitations received from invited member in `x.grp.mem.inv` messages to all other members. This message can only be sent by the member who previously announced the new member, otherwise the recipients MUST ignore it.
+
+`x.grp.mem.info` this message is sent as part of member connection handshake - it includes group member profile.
+
+`x.grp.mem.role` message is sent to update group member role - it is sent to all members by the member who updated the role of the member referenced in this message. This message MUST only be sent by members with `admin` or `owner` role. Receiving clients MUST ignore this message if it is received from member with role less than `admin`.
+
+`x.grp.mem.restrict` message is sent to group members to communicate group member restrictions, such as member being blocked for sending messages.
+
+`x.grp.mem.con` message is sent by members connecting inside group to inviting member, to notify the inviting member they have completed the connection and no longer require forwarding messages between them.
+
+`x.grp.mem.del` message is sent to delete a member - it is sent to all members by the member who deletes the member referenced in this message. This message MUST only be sent by members with `admin` or `owner` role. Receiving clients MUST ignore this message if it is received from member with `member` role.
+
+`x.grp.leave` message is sent to all members by the member leaving the group. If the only group `owner` leaves the group, it will not be possible to delete it with `x.grp.del` message - but all members can still leave the group with `x.grp.leave` message and then delete a local copy of the group.
+
+`x.grp.del` message is sent to all members by the member who deletes the group. Clients who received this message SHOULD keep a local copy of the deleted group, until it is deleted by the user. This message MUST only be sent by members with `owner` role. Receiving clients MUST ignore this message if it is received from member other than with `owner` role.
+
+`x.grp.info` message is sent to all members by the member who updated group profile. Only group owners can update group profiles. Clients MAY implement some conflict resolution strategy - it is currently not implemented by SimpleX Chat client. This message MUST only be sent by members with `owner` role. Receiving clients MUST ignore this message if it is received from member other than with `owner` role.
+
+`x.grp.direct.inv` message is sent to a group member to propose establishing a direct connection between members, thus creating a contact with another member.
+
+`x.grp.msg.forward` message is sent by inviting member to forward messages between introduced members, while they are connecting. This message MUST NOT contain another `x.grp.msg.forward` message.
+
+### Channels: relay-mediated groups
+
+Channels are groups where message delivery is mediated by dedicated relay members rather than by direct connections between all members. Channels extend the group sub-protocol with additional roles (`relay`, `observer`), message signing for administrative actions, a binary batch format for signed and forwarded messages, and an asynchronous delivery pipeline.
+
+For architecture and design rationale, see [SimpleX Channels Overview](https://simplex.chat/docs/protocol/channels-overview.md). For protocol-level detail - wire formats, message types, signing mechanics, delivery pipeline - see [SimpleX Channels Protocol](https://simplex.chat/docs/protocol/channels-protocol.md).
+
+## Sub-protocol for WebRTC audio/video calls
+
+This sub-protocol is used to send call invitations and to negotiate end-to-end encryption keys and pass WebRTC signalling information.
+
+These message are used for WebRTC calls:
+
+1. `x.call.inv`: the client initiating the call sends `x.call.inv` message in direct connection to invite another client to the call. At this point WebRTC session is not initialized yet, this message only contains call type and DH key for key agreement.
+
+2. `x.call.offer`: to accept the call, the receiving client sends `x.call.offer` message. This message contains WebRTC offer and collected ICE candidates. Additional ICE candidates can be sent in `x.call.extra` message.
+
+3. `x.call.answer`: to continue with call connection the initiating clients must reply with `x.call.answer` message. This message contains WebRTC answer and collected ICE candidates. Additional ICE candidates can be sent in `x.call.extra` message.
+
+4. `x.call.end` message is sent to notify the other party that the call is terminated.
+
+Call messages have their own version, independent of the chat protocol version. The initiating client sends the range of call versions it supports in `callVRange` property of `x.call.inv`. The receiving client chooses the highest version supported by both clients and sends it in `callVersion` property of `x.call.offer`. The initiating client rejects the offer if this version is not in the range it sent. A missing range or version means version 1.
+
+Media frames are encrypted with AES-256-GCM using the key agreed via X25519 DH keys in `x.call.inv` and `x.call.offer`:
+- version 1: the key is the DH shared secret.
+- version 2: the key is 32 bytes of HKDF-SHA512 output, using the DH shared secret as input key material, call ID as salt and `SimpleXCallMediaKey` as info.
+
+## Threat model
+
+This threat model complements SMP, XFTP, push notifications and XRCP protocols threat models, as well as the channel-specific threat model:
+
+- [SimpleX Messaging Protocol threat model](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md#threat-model);
+- [SimpleX File Transfer Protocol threat model](https://github.com/simplex-chat/simplexmq/blob/master/protocol/xftp.md#threat-model);
+- [Push notifications threat model](https://github.com/simplex-chat/simplexmq/blob/master/protocol/push-notifications.md#threat-model);
+- [SimpleX Remote Control Protocol threat model](https://github.com/simplex-chat/simplexmq/blob/master/protocol/xrcp.md#threat-model);
+- [SimpleX Channels threat model](https://simplex.chat/docs/protocol/channels-overview.md#threat-model).
+
+#### A user's contact
+
+*can:*
+
+- send messages prohibited by user's preferences or otherwise act non-compliantly with user's preferences (for example, if message with updated preferences was lost or failed to be processed, or with modified client), in which case user client should treat such messages and actions as prohibited.
+
+- by exchanging special messages with user's client, match user's contact with existing group members and/or contacts that have identical user profile (see [Probing for duplicate contacts](#probing-for-duplicate-contacts)).
+
+- identify that and when a user is using SimpleX, in case user has delivery receipts enabled, or based on other automated client responses.
+
+*cannot:*
+
+- match user's contact with existing group members and/or contacts with different or with incognito profiles.
+
+- match user's contact without communicating with the user's client.
+
+#### A group member
+
+*can:*
+
+- send messages prohibited by group's preferences and member restrictions or otherwise act non-compliantly with preferences and restrictions (for example, if decentralized group state diverged, or with modified client), in which case user client should treat such messages and actions as prohibited.
+
+- create a direct contact with a user if group permissions allow it.
+
+- by exchanging special messages with user's client, match user's group member record with the existing group members and/or contacts that have identical user profile.
+
+- undetectably send different messages to different group members, or selectively send messages to some members and not send to others.
+
+- identify that and when a user is using SimpleX, in case user has delivery receipts enabled, or based on other automated client responses.
+
+- join the same group several times, from the same or from different user profile, and pretend to be different members.
+
+*cannot:*
+
+- match user's contact with existing group members and/or contacts with different or with incognito profiles.
+
+- match user's group member record with existing group members and/or contacts without communication of user's client.
+
+- determine whether two group members with different or with incognito profiles are the same user.
+
+#### A group admin
+
+*can:*
+
+- carry out MITM attack between user and other group member(s) when forwarding invitations for group connections (user can detect such attack by verifying connection security codes out-of-band).
+
+- undetectably forward different messages to different group members, selectively adding, modifying, and dropping forwarded messages.
+
+- disrupt decentralized group state by sending different messages that change group state (such as adding or removing members, member role changes, etc.) to different group members, or sending such messages selectively.
+
+*cannot:*
+
+- prove that two group members with incognito profiles is the same user.
+
+#### A channel relay
+
+For the full channel threat model, see [SimpleX Channels: threat model](https://simplex.chat/docs/protocol/channels-overview.md#threat-model).
+
+*can:*
+
+- send arbitrary unsigned content messages to subscribers, effectively fabricating the content stream while the channel identity and signed profile remain intact.
+
+- selectively drop any messages, both content and signed administrative events, for some or all subscribers.
+
+- ignore the "message from channel" directive, revealing which specific owner sent a message.
+
+- fabricate subscriber connections, inflating subscriber counts.
+
+*cannot:*
+
+- impersonate an owner - administrative messages (roster changes, profile updates, channel deletion) require valid cryptographic signatures that the relay cannot produce.
+
+- substitute the channel profile - profile changes require a valid owner signature.
+
+- redirect joining subscribers to a different channel - the channel's entity ID is baked into both the channel link and the relay link's immutable data.
+
+- determine the real-world identity of subscribers - subscriber connections carry no persistent identity.
diff --git a/docs/server.html b/docs/server.html
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--- a/docs/server.html
+++ b/docs/server.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/server.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/server.md b/docs/server.md
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--- /dev/null
+++ b/docs/server.md
@@ -0,0 +1,1719 @@
+# Hosting your own SMP Server
+
+| Updated 12.10.2024 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/server.html), [CZ](https://simplex.chat/docs/lang/cs/server.html), [PL](https://simplex.chat/docs/lang/pl/server.html) |
+
+## Table of Contents
+
+- [Overview](#overview)
+- [Quick start](#quick-start) with systemd service
+- [Installation options](#installation-options)
+   - [systemd service](#systemd-service) with [installation script](#installation-script) or [manually](#manual-deployment)
+   - [docker container](#docker-container)
+   - [Linode marketplace](#linode-marketplace)
+- [Verifying server binaries](#verifying-server-binaries)
+- [Configuration](#configuration)
+   - [Interactively](#interactively)
+   - [Via command line options](#via-command-line-options)
+- [Further configuration](#further-configuration)
+- [Server security](#server-security)
+   - [Initialization](#initialization)
+   - [Private keys](#private-keys)
+   - [Online certificate rotation](#online-certificate-rotation)
+- [Tor: installation and configuration](#tor-installation-and-configuration)
+   - [Installation for onion address](#installation-for-onion-address)
+   - [SOCKS port for SMP PROXY](#socks-port-for-smp-proxy)
+- [Server information page](#server-information-page)
+- [Name resolution](#name-resolution)
+- [Documentation](#documentation)
+   - [SMP server address](#smp-server-address)
+   - [Systemd commands](#systemd-commands)
+   - [Control port](#control-port)
+   - [Daily statistics](#daily-statistics)
+- [Reproduce builds](#reproduce-builds)
+- [Updating your SMP server](#updating-your-smp-server)
+- [Configuring the app to use the server](#configuring-the-app-to-use-the-server)
+
+## Overview
+
+SMP server is the relay server used to pass messages in SimpleX network. SimpleX Chat apps have preset servers (for mobile apps these are smp11, smp12 and smp14.simplex.im), but you can easily change app configuration to use other servers.
+
+SimpleX clients only determine which server is used to receive the messages, separately for each contact (or group connection with a group member), and these servers are only temporary, as the delivery address can change.
+
+To create SMP server, you'll need:
+
+1. VPS or any other server.
+2. Your own domain, pointed at the server (`smp.example.com`)
+3. A basic Linux knowledge.
+
+_Please note_: when you change the servers in the app configuration, it only affects which servers will be used for the new contacts, the existing contacts will not automatically move to the new servers, but you can move them manually using ["Change receiving address"](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md#change-your-delivery-address-beta) button in contact/member information pages – it will be automated in the future.
+
+## Quick start
+
+To create SMP server as a systemd service, you'll need:
+
+- VPS or any other server.
+- Your server domain, with A and AAAA records specifying server IPv4 and IPv6 addresses (`smp1.example.com`)
+- A basic Linux knowledge.
+
+*Please note*: while you can run an SMP server without a domain name, in the near future client applications will start using server domain name in the invitation links (instead of `simplex.chat` domain they use now). In case a server does not have domain name and server pages (see below), the clients will be generating the links with `simplex:` scheme that cannot be opened in the browsers.
+
+1. Install server with [Installation script](https://github.com/simplex-chat/simplexmq#using-installation-script).
+
+2. Adjust firewall:
+
+   ```sh
+   ufw allow 80/tcp &&\
+   ufw allow 443/tcp &&\
+   ufw allow 5223/tcp
+   ```
+
+3. Init server:
+
+   Replace `smp1.example.com` with your actual server domain.
+
+   ```sh
+   su smp -c 'smp-server init --yes \
+                           --store-log \
+                           --no-password \
+                           --control-port \
+                           --socks-proxy \
+                           --source-code \
+                           --fqdn=smp1.example.com'
+   ```
+
+4. Install tor:
+
+   ```sh
+   CODENAME="$(lsb_release -c | awk '{print $2}')"
+
+   echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main
+   deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main" > /etc/apt/sources.list.d/tor.list &&\
+   curl --proto '=https' --tlsv1.2 -sSf https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null &&\
+   apt update && apt install -y tor deb.torproject.org-keyring
+   ```
+
+5. Configure tor:
+
+   ```sh
+   tor-instance-create tor2 &&\
+   mkdir /var/lib/tor/simplex-smp/ &&\
+   chown debian-tor:debian-tor /var/lib/tor/simplex-smp/ &&\
+   chmod 700 /var/lib/tor/simplex-smp/
+   ```
+
+   ```sh
+   vim /etc/tor/torrc
+   ```
+
+   Paste the following:
+
+   ```sh
+   # Enable log (otherwise, tor doesn't seem to deploy onion address)
+   Log notice file /var/log/tor/notices.log
+   # Enable single hop routing (2 options below are dependencies of the third) - It will reduce the latency at the cost of lower anonymity of the server - as SMP-server onion address is used in the clients together with public address, this is ok. If you deploy SMP-server with onion-only address, keep standard configuration.
+   SOCKSPort 0
+   HiddenServiceNonAnonymousMode 1
+   HiddenServiceSingleHopMode 1
+   # smp-server hidden service host directory and port mappings
+   HiddenServiceDir /var/lib/tor/simplex-smp/
+   HiddenServicePort 5223 localhost:5223
+   HiddenServicePort 443 localhost:443
+   ```
+
+   ```sh
+   vim /etc/tor/instances/tor2/torrc
+   ```
+
+   Paste the following:
+
+   ```sh
+   # Log tor to systemd daemon
+   Log notice syslog
+   # Listen to local 9050 port for socks proxy
+   SocksPort 9050
+   ```
+
+6. Start tor:
+
+   ```sh
+   systemctl enable tor &&\
+   systemctl start tor &&\
+   systemctl restart tor &&\
+   systemctl enable --now tor@tor2
+   ```
+
+7. Install Caddy:
+
+   ```sh
+   sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl &&\
+   curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg &&\
+   curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list &&\
+   sudo apt update && sudo apt install caddy
+   ```
+
+8. Configure Caddy:
+
+   ```sh
+   vim /etc/caddy/Caddyfile
+   ```
+
+   Replace `smp1.example.com` with your actual server domain. Paste the following:
+
+   ```
+   http://smp1.example.com {
+      redir https://smp1.example.com{uri} permanent
+   }
+
+   smp1.example.com:8443 {
+      tls {
+         key_type rsa4096
+      }
+   }
+   ```
+
+   ```sh
+   vim /usr/local/bin/simplex-servers-certs
+   ```
+
+   Replace `smp1.example.com` with your actual server domain. Paste the following:
+
+   ```sh
+   #!/usr/bin/env sh
+   set -eu
+
+   user='smp'
+   group="$user"
+
+   domain='smp1.example.com'
+   folder_in="/var/lib/caddy/.local/share/caddy/certificates/acme-v02.api.letsencrypt.org-directory/${domain}"
+   folder_out='/etc/opt/simplex'
+   key_name='web.key'
+   cert_name='web.crt'
+
+   # Copy certificate from Caddy directory to smp-server directory
+   cp "${folder_in}/${domain}.crt" "${folder_out}/${cert_name}"
+   # Assign correct permissions
+   chown "$user":"$group" "${folder_out}/${cert_name}"
+
+   # Copy certificate key from Caddy directory to smp-server directory
+   cp "${folder_in}/${domain}.key" "${folder_out}/${key_name}"
+   # Assign correct permissions
+   chown "$user":"$group" "${folder_out}/${key_name}"
+   ```
+
+   ```sh
+   chmod +x /usr/local/bin/simplex-servers-certs
+   ```
+
+   ```sh
+   sudo crontab -e
+   ```
+
+   Paste the following:
+
+   ```sh
+   # Every week on 00:20 sunday
+   20 0 * * 0 /usr/local/bin/simplex-servers-certs
+   ```
+
+9. Enable and start Caddy service:
+
+   Wait until "good to go" has been printed.
+
+   ```sh
+   systemctl enable --now caddy &&\
+   sleep 10 &&\
+   /usr/local/bin/simplex-servers-certs &&\
+   echo 'good to go'
+   ```
+
+10. Enable and start smp-server:
+
+    ```sh
+    systemctl enable --now smp-server.service
+    ```
+
+11. Print your address:
+
+    ```sh
+    smp="$(journalctl --output cat -q _SYSTEMD_INVOCATION_ID="$(systemctl show -p InvocationID --value smp-server)" | grep -m1 'Server address:' | awk '{print $NF}' | sed 's/:443.*//')"
+    tor="$(cat /var/lib/tor/simplex-smp/hostname)"
+
+    echo "$smp,$tor"
+    ```
+
+## Installation options
+
+You can install SMP server in one of the following ways:
+
+- [systemd service](#systemd-service)
+   - using [installation script](#installation-script) - **recommended**
+   - or [manually](#manual-deployment)
+- [Docker container](#docker-container) from DockerHub
+- [Linode marketplace](#linode-marketplace)
+
+### systemd service
+
+#### Installation script
+
+This installation script will automatically install binaries, systemd services and additional scripts that will manage backups, updates and uninstallation. This is the recommended option due to its flexibility, easy updating, and being battle tested on our servers.
+
+**Please note** that currently only Ubuntu distribution is supported.
+
+Run the following script on the server:
+
+```sh
+curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/install.sh -o simplex-server-install.sh &&\
+if echo '53fcdb4ceab324316e2c4cda7e84dbbb344f32550a65975a7895425e5a1be757 simplex-server-install.sh' | sha256sum -c; then
+  chmod +x ./simplex-server-install.sh
+  ./simplex-server-install.sh
+  rm ./simplex-server-install.sh
+else
+  echo "SHA-256 checksum is incorrect!"
+  rm ./simplex-server-install.sh
+fi
+```
+
+Type `1` and hit enter to install `smp-server`.
+
+#### Manual deployment
+
+Manual installation is the most advanced deployment that provides the most flexibility. Generally recommended only for advanced users.
+
+1. Install binary:
+
+   - Using pre-compiled binaries:
+
+     ```sh
+     curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/smp-server && chmod +x /usr/local/bin/smp-server
+     ```
+
+   - Compiling from source:
+
+     Please refer to [Build from source: Using your distribution](https://github.com/simplex-chat/simplexmq#using-your-distribution)
+
+2. Create user and group for `smp-server`:
+
+   ```sh
+   sudo useradd -m smp
+   ```
+
+3. Create necessary directories and assign permissions:
+
+   ```sh
+   sudo mkdir -p /var/opt/simplex /etc/opt/simplex
+   sudo chown smp:smp /var/opt/simplex /etc/opt/simplex
+   ```
+
+4. Allow `smp-server` port in firewall:
+
+   ```sh
+   # For Ubuntu
+   sudo ufw allow 5223/tcp
+   sudo ufw allow 443/tcp
+   sudo ufw allow 80/tcp
+   # For Fedora
+   sudo firewall-cmd --permanent --add-port=5223/tcp --add-port=443/tcp --add-port=80/tcp && \
+   sudo firewall-cmd --reload
+   ```
+
+5. **Optional** — If you're using distribution with `systemd`, create `/etc/systemd/system/smp-server.service` file with the following content:
+
+   ```sh
+   [Unit]
+   Description=SMP server systemd service
+
+   [Service]
+   User=smp
+   Group=smp
+   Type=simple
+   ExecStart=/usr/local/bin/smp-server start +RTS -N -RTS
+   ExecStopPost=/usr/bin/env sh -c '[ -e "/var/opt/simplex/smp-server-store.log" ] && cp "/var/opt/simplex/smp-server-store.log" "/var/opt/simplex/smp-server-store.log.bak"'
+   LimitNOFILE=65535
+   KillSignal=SIGINT
+   TimeoutStopSec=infinity
+   AmbientCapabilities=CAP_NET_BIND_SERVICE
+
+   [Install]
+   WantedBy=multi-user.target
+   ```
+
+   And execute `sudo systemctl daemon-reload`.
+
+### Docker container
+
+You can deploy smp-server using Docker Compose. This is second recommended option due to its popularity and relatively easy deployment.
+
+This deployment provides two Docker Compose files: the **automatic** one and **manual**. If you're not sure, choose **automatic**.
+
+This will download images from [Docker Hub](https://hub.docker.com/r/simplexchat).
+
+#### Docker: Automatic setup
+
+This configuration provides quick and easy way to setup your SMP server: Caddy will automatically manage Let's Encrypt certificates and redirect HTTP to HTTPS, while smp-server will serve both [server information page](#server-information-page) and SMP Protocol by 443 port. 5223 port is used as fallback.
+
+**Please note** that you _must_ have `80` and `443` ports unallocated by other servers.
+
+1. Create `smp-server` directory and switch to it:
+
+  ```sh
+  mkdir smp-server && cd smp-server
+  ```
+
+2. Create `docker-compose.yml` file with the following content:
+
+  You can also grab it from here - [docker-compose-smp-complete.yml](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-smp-complete.yml). Don't forget to rename it to `docker-compose.yml`.
+
+  ```yaml
+  name: SimpleX Chat - smp-server
+
+  services:
+    oneshot:
+      image: ubuntu:latest
+      environment:
+        CADDYCONF: |
+          ${CADDY_OPTS:-}
+
+          http://{$$ADDR} {
+              redir https://{$$ADDR}{uri} permanent
+          }
+
+          {$$ADDR}:8443 {
+              tls {
+                  key_type rsa4096
+              }
+          }
+      command: sh -c 'if [ ! -f /etc/caddy/Caddyfile ]; then printf "$${CADDYCONF}" > /etc/caddy/Caddyfile; fi'
+      volumes:
+        - ./caddy_conf:/etc/caddy
+
+    caddy:
+      image: caddy:latest
+      depends_on:
+        oneshot:
+          condition: service_completed_successfully
+      cap_add:
+        - NET_ADMIN
+      environment:
+        ADDR: ${ADDR?"Please specify the domain."}
+      volumes:
+        - ./caddy_conf:/etc/caddy
+        - caddy_data:/data
+        - caddy_config:/config
+      ports:
+        - 80:80
+      restart: unless-stopped
+      healthcheck:
+        test: "test -d /data/caddy/certificates/${CERT_PATH:-acme-v02.api.letsencrypt.org-directory}/${ADDR} || exit 1"
+        interval: 1s
+        retries: 60
+
+    smp-server:
+      image: ${SIMPLEX_IMAGE:-simplexchat/smp-server:latest}
+      depends_on:
+        caddy:
+          condition: service_healthy
+      environment:
+        ADDR: ${ADDR?"Please specify the domain."}
+        PASS: ${PASS:-}
+      volumes:
+        - ./smp_configs:/etc/opt/simplex
+        - ./smp_state:/var/opt/simplex
+        - type: volume
+          source: caddy_data
+          target: /certificates
+          volume:
+            subpath: "caddy/certificates/${CERT_PATH:-acme-v02.api.letsencrypt.org-directory}/${ADDR}"
+      ports:
+        - 443:443
+        - 5223:5223
+      restart: unless-stopped
+
+  volumes:
+    caddy_data:
+    caddy_config:
+  ```
+
+3. In the same directory, create `.env` file with the following content:
+
+  You can also grab it from here - [docker-compose-smp-complete.env](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-smp-complete.env). Don't forget to rename it to `.env`.
+
+  Change variables according to your preferences.
+
+  ```env
+  # Mandatory
+  ADDR=your_ip_or_addr
+
+  # Optional
+  #PASS='123123'
+  ```
+
+4. Start your containers:
+
+  ```sh
+  docker compose up
+  ```
+
+#### Docker: Manual setup
+
+If you know what you are doing, this configuration provides bare SMP server setup without automatically managed Let's Encrypt certificates by Caddy to serve [server information page](#server-information-page) with 5223 port set as primary.
+
+This configuration allows you to retain the ability to manage 80 and 443 ports yourself. As a downside, SMP server **can not* be served to 443 port.
+
+1. Create `smp-server` directory and switch to it:
+
+  ```sh
+  mkdir smp-server && cd smp-server
+  ```
+
+2. Create `docker-compose.yml` file with the following content:
+
+  You can also grab it from here - [docker-compose-smp-manual.yml](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-smp-manual.yml). Don't forget to rename it to `docker-compose.yml`.
+
+  ```yaml
+  name: SimpleX Chat - smp-server
+
+  services:
+    smp-server:
+      image: ${SIMPLEX_IMAGE:-simplexchat/smp-server:latest}
+      environment:
+        WEB_MANUAL: ${WEB_MANUAL:-1}
+        ADDR: ${ADDR?"Please specify the domain."}
+        PASS: ${PASS:-}
+      volumes:
+        - ./smp_configs:/etc/opt/simplex
+        - ./smp_state:/var/opt/simplex
+      ports:
+        - 5223:5223
+      restart: unless-stopped
+  ```
+
+3. In the same directory, create `.env` file with the following content:
+
+  You can also grab it from here - [docker-compose-smp-manual.env](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-smp-manual.env). Don't forget to rename it to `.env`.
+
+  Change variables according to your preferences.
+
+  ```env
+  # Mandatory
+  ADDR=your_ip_or_addr
+
+  # Optional
+  #PASS='123123'
+  WEB_MANUAL=1
+  ```
+
+4. Start your containers:
+
+  ```sh
+  docker compose up
+  ```
+
+### Linode marketplace
+
+You can deploy smp-server upon creating new Linode VM. Please refer to: [Linode Marketplace](https://www.linode.com/marketplace/apps/simplex-chat/simplex-chat/)
+
+## Verifying server binaries
+
+Starting from v6.3 server builds are [reproducible](#reproduce-builds).
+
+That also allows us to sign server releases, confirming the integrity of GitHub builds.
+
+To verify server binaries after you downloaded them:
+
+1. Download `_sha256sums` (hashes of all server binaries) and `_sha256sums.asc` (signature).
+
+2. Download our key FB44AF81A45BDE327319797C85107E357D4A17FC from [openpgp.org](https://keys.openpgp.org/search?q=chat%40simplex.chat)
+
+3. Import the key with `gpg --import FB44AF81A45BDE327319797C85107E357D4A17FC`. Key filename should be the same as its fingerprint, but please change it if necessary.
+
+4. Run `gpg --verify _sha256sums.asc _sha256sums`. It should print:
+
+> Good signature from "SimpleX Chat <chat@simplex.chat>"
+
+5. Compute the hashes of the binaries you plan to use with `sha256sum <file>` or with `openssl sha256 <file>` and compare them with the hashes in the file `_sha256sums` - they must be the same.
+
+That is it - you now verified authenticity of our GitHub server binaries.
+
+## Configuration
+
+To see which options are available, execute `smp-server` without flags:
+
+```sh
+sudo su smp -c smp-server
+
+...
+Available commands:
+  init                     Initialize server - creates /etc/opt/simplex and
+                           /var/opt/simplex directories and configuration files
+  start                    Start server (configuration:
+                           /etc/opt/simplex/smp-server.ini)
+  delete                   Delete configuration and log files
+```
+
+You can get further help by executing `sudo su smp -c "smp-server <command> -h"`
+
+After that, we need to configure `smp-server`:
+
+### Interactively
+
+Execute the following command:
+
+```sh
+sudo su smp -c "smp-server init"
+```
+
+There are several options to consider:
+
+- `Enable store log to restore queues and messages on server restart (Yn):`
+
+  Enter `y` to enable saving and restoring connections and messages when the server is restarted.
+
+  _Please note_: it is important to use SIGINT to restart the server, as otherwise the undelivered messages will not be restored. The connections will be restored irrespective of how the server is restarted, as unlike messages they are added to append-only log on every change.
+
+- `Enable logging daily statistics (yN):`
+
+  Enter `y` to enable logging statistics in CSV format, e.g. they can be used to show aggregate usage charts in `Grafana`.
+
+These statistics include daily counts of created, secured and deleted queues, sent and received messages, and also daily, weekly, and monthly counts of active queues (that is, the queues that were used for any messages). We believe that this information does not include anything that would allow correlating different queues as belonging to the same users, but please [let us know](https://simplex.chat/security/index.html), confidentially, if you believe that this can be exploited in any way.
+
+- `Require a password to create new messaging queues?`
+
+  Press `Enter` or enter your arbitrary password to password-protect `smp-server`, or `n` to disable password protection.
+
+- `Enter server FQDN or IP address for certificate (127.0.0.1):`
+
+  Enter your domain or ip address that your smp-server is running on - it will be included in server certificates and also printed as part of server address.
+
+### Via command line options
+
+Execute the following command:
+
+```sh
+sudo su smp -c "smp-server init -h"
+
+...
+Available options:
+  -l,--store-log           Enable store log for persistence
+  -s,--daily-stats         Enable logging daily server statistics
+  -a,--sign-algorithm ALG  Signature algorithm used for TLS certificates:
+                           ED25519, ED448 (default: ED448)
+  --ip IP                  Server IP address, used as Common Name for TLS online
+                           certificate if FQDN is not supplied
+                           (default: "127.0.0.1")
+  -n,--fqdn FQDN           Server FQDN used as Common Name for TLS online
+                           certificate
+  --no-password            Allow creating new queues without password
+  --password PASSWORD      Set password to create new messaging queues
+  -y,--yes                 Non-interactive initialization using command-line
+                           options
+  -h,--help                Show this help text
+```
+
+You should determine which flags are needed for your use-case and then execute `smp-server init` with `-y` flag for non-interactive initialization:
+
+```sh
+sudo su smp -c "smp-server init -y -<your flag> <your option>"
+```
+
+For example, run:
+
+```sh
+sudo su smp -c "smp-server init -y -l --ip 192.168.1.5 --password test"
+```
+
+to initialize your `smp-server` configuration with:
+
+- restoring connections and messages when the server is restarted (`-l` flag),
+- IP address `192.168.1.5`,
+- protect `smp-server` with a password `test`.
+
+---
+
+After that, your installation is complete and you should see in your terminal output something like this:
+
+```sh
+Certificate request self-signature ok
+subject=CN = 127.0.0.1
+Server initialized, you can modify configuration in /etc/opt/simplex/smp-server.ini.
+Run `smp-server start` to start server.
+----------
+You should store CA private key securely and delete it from the server.
+If server TLS credential is compromised this key can be used to sign a new one, keeping the same server identity and established connections.
+CA private key location: /etc/opt/simplex/ca.key
+----------
+SMP server v3.4.0
+Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
+Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>
+```
+
+The server address above should be used in your client configuration, and if you added server password it should only be shared with the other people who you want to allow using your server to receive the messages (all your contacts will be able to send messages - it does not require a password). If you passed IP address or hostnames during the initialisation, they will be printed as part of server address, otherwise replace `<hostnames>` with the actual server hostnames.
+
+## Further configuration
+
+All generated configuration, along with a description for each parameter, is available inside configuration file in `/etc/opt/simplex/smp-server.ini` for further customization. Depending on the smp-server version, the configuration file looks something like this:
+
+```ini
+[INFORMATION]
+# AGPLv3 license requires that you make any source code modifications
+# available to the end users of the server.
+# LICENSE: https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE
+# Include correct source code URI in case the server source code is modified in any way.
+# If any other information fields are present, source code property also MUST be present.
+
+source_code: https://github.com/simplex-chat/simplexmq
+
+# Declaring all below information is optional, any of these fields can be omitted.
+
+# Server usage conditions and amendments.
+# It is recommended to use standard conditions with any amendments in a separate document.
+# usage_conditions: https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md
+# condition_amendments: link
+
+# Server location and operator.
+# server_country: ISO-3166 2-letter code
+# operator: entity (organization or person name)
+# operator_country: ISO-3166 2-letter code
+# website:
+
+# Administrative contacts.
+# admin_simplex: SimpleX address
+# admin_email:
+# admin_pgp:
+# admin_pgp_fingerprint:
+
+# Contacts for complaints and feedback.
+# complaints_simplex: SimpleX address
+# complaints_email:
+# complaints_pgp:
+# complaints_pgp_fingerprint:
+
+# Hosting provider.
+# hosting: entity (organization or person name)
+# hosting_country: ISO-3166 2-letter code
+
+[STORE_LOG]
+# The server uses STM memory for persistence,
+# that will be lost on restart (e.g., as with redis).
+# This option enables saving memory to append only log,
+# and restoring it when the server is started.
+# Log is compacted on start (deleted objects are removed).
+enable: on
+
+# Undelivered messages are optionally saved and restored when the server restarts,
+# they are preserved in the .bak file until the next restart.
+restore_messages: on
+expire_messages_days: 21
+expire_ntfs_hours: 24
+
+# Log daily server statistics to CSV file
+log_stats: on
+
+[AUTH]
+# Set new_queues option to off to completely prohibit creating new messaging queues.
+# This can be useful when you want to decommission the server, but not all connections are switched yet.
+new_queues: on
+
+# Use create_password option to enable basic auth to create new messaging queues.
+# The password should be used as part of server address in client configuration:
+# smp://fingerprint:password@host1,host2
+# The password will not be shared with the connecting contacts, you must share it only
+# with the users who you want to allow creating messaging queues on your server.
+# create_password: password to create new queues (any printable ASCII characters without whitespace, '@', ':' and '/')
+
+# control_port_admin_password:
+# control_port_user_password:
+
+[TRANSPORT]
+# Host is only used to print server address on start.
+# You can specify multiple server ports.
+host: <domain/ip>
+port: 5223,443
+log_tls_errors: off
+
+# Use `websockets: 443` to run websockets server in addition to plain TLS.
+websockets: off
+# control_port: 5224
+
+[PROXY]
+# Network configuration for SMP proxy client.
+# `host_mode` can be 'public' (default) or 'onion'.
+# It defines preferred hostname for destination servers with multiple hostnames.
+# host_mode: public
+# required_host_mode: off
+
+# The domain suffixes of the relays you operate (space-separated) to count as separate proxy statistics.
+# own_server_domains: 
+
+# SOCKS proxy port for forwarding messages to destination servers.
+# You may need a separate instance of SOCKS proxy for incoming single-hop requests.
+# socks_proxy: localhost:9050
+
+# `socks_mode` can be 'onion' for SOCKS proxy to be used for .onion destination hosts only (default)
+# or 'always' to be used for all destination hosts (can be used if it is an .onion server).
+# socks_mode: onion
+
+# Limit number of threads a client can spawn to process proxy commands in parallel.
+# client_concurrency: 32
+
+[INACTIVE_CLIENTS]
+# TTL and interval to check inactive clients
+disconnect: off
+# ttl: 21600
+# check_interval: 3600
+
+[WEB]
+# Set path to generate static mini-site for server information and qr codes/links
+static_path: /var/opt/simplex/www
+
+# Run an embedded server on this port
+# Onion sites can use any port and register it in the hidden service config.
+# Running on a port 80 may require setting process capabilities.
+#http: 8000
+
+# You can run an embedded TLS web server too if you provide port and cert and key files.
+# Not required for running relay on onion address.
+https: 443
+cert: /etc/opt/simplex/web.crt
+key: /etc/opt/simplex/web.key
+```
+
+## Server security
+
+### Initialization
+
+Although it's convenient to initialize smp-server configuration directly on the server, operators **ARE ADVISED** to initialize smp-server fully offline to protect your SMP server CA private key.
+
+Follow the steps to quickly initialize the server offline:
+
+1. Install Docker on your system.
+
+2. Deploy [smp-server](https://github.com/simplex-chat/simplexmq#using-docker) locally.
+
+3. Destroy the container. All relevant configuration files and keys will be available at `$HOME/simplex/smp/config`.
+
+4. Move your `CA` private key (`ca.key`) to the safe place. For further explanation, see the next section: [Server security: Private keys](#private-keys).
+
+5. Copy all other configuration files **except** the CA key to the server:
+
+   ```sh
+   rsync -hzasP $HOME/simplex/smp/config/ <server_user>@<server_address>:/etc/opt/simplex/
+   ```
+
+### Private keys
+
+Connection to the smp server occurs via a TLS connection. During the TLS handshake, the client verifies smp-server CA and server certificates by comparing its fingerprint with the one included in server address. If server TLS credential is compromised, this key can be used to sign a new one, keeping the same server identity and established connections. In order to protect your smp-server from bad actors, operators **ARE ADVISED** to move CA private key to a safe place. That could be:
+
+- [Tails](https://tails.net/) live usb drive with [persistent and encrypted storage](https://tails.net/doc/persistent_storage/create/index.en.html).
+- Offline Linux laptop.
+- Bitwarden.
+- Any other safe storage that satisfy your security requirements.
+
+Follow the steps to secure your CA keys:
+
+1. Login to your server via SSH.
+
+2. Copy the CA key to a safe place from this file:
+
+   ```sh
+   /etc/opt/simplex/ca.key
+   ```
+
+3. Delete the CA key from the server. **Please make sure you've saved your CA key somewhere safe. Otherwise, you would lose the ability to [rotate the online certificate](#online-certificate-rotation)**:
+
+   ```sh
+   rm /etc/opt/simplex/ca.key
+   ```
+
+### Online certificate rotation
+
+Operators of smp servers **ARE ADVISED** to rotate online certificate regularly (e.g., every 3 months). In order to do this, follow the steps:
+
+1. Create relevant folders:
+
+   ```sh
+   mkdir -p $HOME/simplex/smp/config
+   ```
+
+1. Copy the configuration files from the server to the local machine (if not yet):
+
+   ```sh
+   rsync -hzasP <server_user>@<server_address>:/etc/opt/simplex/ $HOME/simplex/smp/config/
+   ```
+
+2. **Copy** your CA private key from a safe place to the local machine and name it `ca.key`.
+
+3. Download latest `smp-server` binary [from Github releases](https://github.com/simplex-chat/simplexmq/releases):
+
+   ```sh
+   curl -L 'https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64' -o smp-server
+   ```
+
+4. Put the `smp-server` binary to your `$PATH` and make it executable:
+
+   ```sh
+   sudo mv smp-server /usr/local/bin/ && chmod +x /usr/local/bin/smp-server
+   ```
+
+5. Export a variable to configure your path to smp-server configuration:
+
+   ```sh
+   export SMP_SERVER_CFG_PATH=$HOME/simplex/smp/config
+   ```
+
+6. Execute the following command:
+
+   ```sh
+   smp-server cert
+   ```
+
+   This command should print:
+
+   ```sh
+   Certificate request self-signature ok
+   subject=CN = <your domain or IP>
+   Generated new server credentials
+   ----------
+   You should store CA private key securely and delete it from the server.
+   If server TLS credential is compromised this key can be used to sign a new one, keeping the same server identity and established connections.
+   CA private key location:
+   $HOME/simplex/smp/config/ca.key
+   ----------
+   ```
+
+7. Remove the CA key from the config folder (make sure you have a backup!):
+
+   ```sh
+   rm $HOME/simplex/smp/config/ca.key
+   ```
+
+8. Upload new certificates to the server:
+
+   ```sh
+   rsync -hzasP $HOME/simplex/smp/config/ <server_user>@<server_address>:/etc/opt/simplex/
+   ```
+
+9. Connect to the server via SSH and restart the service:
+
+   ```sh
+   ssh <server_user>@<server_address> "systemctl restart smp-server"
+   ```
+
+10. Done!
+
+## Tor: installation and configuration
+
+### Installation for onion address
+
+SMP-server can also be deployed to be available via [Tor](https://www.torproject.org) network. Run the following commands as `root` user.
+
+1. Install tor:
+
+   We're assuming you're using Ubuntu/Debian based distributions. If not, please refer to [official tor documentation](https://community.torproject.org/onion-services/setup/install/) or your distribution guide.
+
+   - Configure official Tor PPA repository:
+
+     ```sh
+     CODENAME="$(lsb_release -c | awk '{print $2}')"
+     echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main
+     deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main" > /etc/apt/sources.list.d/tor.list
+     ```
+
+   - Import repository key:
+
+     ```sh
+     curl --proto '=https' --tlsv1.2 -sSf https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null
+     ```
+
+   - Update repository index:
+
+     ```sh
+     apt update
+     ```
+
+   - Install `tor` package:
+
+     ```sh
+     apt install -y tor deb.torproject.org-keyring
+     ```
+
+2. Configure tor:
+
+   - File configuration:
+  
+     Open tor configuration with your editor of choice (`nano`,`vim`,`emacs`,etc.):
+
+     ```sh
+     vim /etc/tor/torrc
+     ```
+
+     And insert the following lines to the bottom of configuration. Please note lines starting with `#`: these are comments about each individual option.
+
+     ```sh
+     # Enable log (otherwise, tor doesn't seem to deploy onion address)
+     Log notice file /var/log/tor/notices.log
+     # Enable single hop routing (2 options below are dependencies of the third) - It will reduce the latency at the cost of lower anonymity of the server - as SMP-server onion address is used in the clients together with public address, this is ok. If you deploy SMP-server with onion-only address, you may want to keep standard configuration instead.
+     SOCKSPort 0
+     HiddenServiceNonAnonymousMode 1
+     HiddenServiceSingleHopMode 1
+     # smp-server hidden service host directory and port mappings
+     HiddenServiceDir /var/lib/tor/simplex-smp/
+     HiddenServicePort 5223 localhost:5223
+     HiddenServicePort 443 localhost:443
+     ```
+
+   - Create directories:
+
+     ```sh
+     mkdir /var/lib/tor/simplex-smp/ && chown debian-tor:debian-tor /var/lib/tor/simplex-smp/ && chmod 700 /var/lib/tor/simplex-smp/
+     ```
+
+3. Start tor:
+
+   Enable `systemd` service and start tor. Official `tor` is a bit flaky on the first start and may not create onion host address, so we're restarting it just in case.
+
+   ```sh
+   systemctl enable --now tor && systemctl restart tor
+   ```
+
+4. Display onion host:
+
+   Execute the following command to display your onion host address:
+
+   ```sh
+   cat /var/lib/tor/simplex-smp/hostname
+   ```
+
+### SOCKS port for SMP PROXY
+
+SMP-server versions starting from `v5.8.0-beta.0` can be configured to PROXY smp servers available exclusively through [Tor](https://www.torproject.org) network to be accessible to the clients that do not use Tor. Run the following commands as `root` user.
+
+1. Install tor as described in the [previous section](#installation-for-onion-address).
+
+2. Execute the following command to create a new Tor daemon instance:
+
+   ```sh
+   tor-instance-create tor2
+   ```
+
+3. Open the `tor2` configuration and replace its content with the following lines:
+
+   ```sh
+   vim /etc/tor/instances/tor2/torrc
+   ```
+
+   ```sh
+   # Log tor to systemd daemon
+   Log notice syslog
+   # Listen to local 9050 port for socks proxy
+   SocksPort 9050
+   ```
+
+3. Enable service at startup and start the daemon:
+
+   ```sh
+   systemctl enable --now tor@tor2
+   ```
+
+   You can check `tor2` logs with the following command:
+
+   ```sh
+   journalctl -u tor@tor2
+   ```
+
+4. After [server initialization](#configuration), configure the `PROXY` section like so:
+
+   ```ini
+   ...
+   [PROXY]
+   socks_proxy: 127.0.0.1:9050
+   own_server_domains: <your domain suffixes if using `log_stats: on`>
+   ...
+   ```
+
+## Server information page
+
+SMP server **SHOULD** be configured to serve Web page with server information that can include admin info, server info, provider info, etc. It will also serve connection links, generated using the mobile/desktop apps. Run the following commands as `root` user.
+
+_Please note:_ this configuration is supported since `v6.1.0-beta.2`.
+
+1. Add the following to your smp-server configuration (please modify fields in [INFORMATION] section to include relevant information):
+
+   ```sh
+   vim /etc/opt/simplex/smp-server.ini
+   ```
+
+   ```ini
+   [TRANSPORT]
+   # host is only used to print server address on start
+   host: <domain/ip>
+   port: 443,5223
+   websockets: off
+   log_tls_errors: off
+   control_port: 5224
+
+   [WEB]
+   https: 443
+   static_path: /var/opt/simplex/www
+   cert: /etc/opt/simplex/web.crt
+   key: /etc/opt/simplex/web.key
+
+   [INFORMATION]
+   # AGPLv3 license requires that you make any source code modifications
+   # available to the end users of the server.
+   # LICENSE: https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE
+   # Include correct source code URI in case the server source code is modified in any way.
+   # If any other information fields are present, source code property also MUST be present.
+
+   source_code: https://github.com/simplex-chat/simplexmq
+
+   # Declaring all below information is optional, any of these fields can be omitted.
+
+   # Server usage conditions and amendments.
+   # It is recommended to use standard conditions with any amendments in a separate document.
+   # usage_conditions: https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md
+   # condition_amendments: link
+
+   # Server location and operator.
+   server_country: <YOUR_SERVER_LOCATION>
+   operator: <YOUR_NAME>
+   operator_country: <YOUR_LOCATION>
+   website: <WEBSITE_IF_AVAILABLE>
+  
+   # Administrative contacts.
+   #admin_simplex: SimpleX address
+   admin_email: <EMAIL>
+   # admin_pgp:
+   # admin_pgp_fingerprint:
+
+   # Contacts for complaints and feedback.
+   # complaints_simplex: SimpleX address
+   complaints_email: <COMPLAINTS_EMAIL>
+   # complaints_pgp:
+   # complaints_pgp_fingerprint:
+
+   # Hosting provider.
+   hosting: <HOSTING_PROVIDER_NAME>
+   hosting_country: <HOSTING_PROVIDER_LOCATION> 
+   ```
+
+2. Install the webserver. For easy deployment we'll describe the installation process of [Caddy](https://caddyserver.com) webserver on Ubuntu server:
+
+   1. Install the packages:
+
+      ```sh
+      sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl
+      ```
+
+   2. Install caddy gpg key for repository:
+
+      ```sh
+      curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
+      ```
+
+   3. Install Caddy repository:
+
+      ```sh
+      curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
+      ```
+
+   4. Install Caddy:
+
+      ```sh
+      sudo apt update && sudo apt install caddy
+      ```
+
+   [Full Caddy installation instructions](https://caddyserver.com/docs/install)
+
+3. Replace Caddy configuration with the following:
+
+   Please replace `YOUR_DOMAIN` with your actual domain (smp.example.com).
+
+   ```sh
+   vim /etc/caddy/Caddyfile
+   ```
+
+   ```
+   http://YOUR_DOMAIN {
+      redir https://YOUR_DOMAIN{uri} permanent
+   }
+
+   YOUR_DOMAIN:8443 {
+      tls {
+         key_type rsa4096
+      }
+   }
+   ```
+
+4. Enable and start Caddy service:
+
+   ```sh
+   systemctl enable --now caddy
+   ```
+
+5. Create script to copy certificates to your smp directory:
+
+   Please replace `YOUR_DOMAIN` with your actual domain (smp.example.com).
+
+   ```sh
+   vim /usr/local/bin/simplex-servers-certs
+   ```
+
+   ```sh
+   #!/usr/bin/env sh
+   set -eu
+
+   user='smp'
+   group="$user"
+
+   domain='HOST'
+   folder_in="/var/lib/caddy/.local/share/caddy/certificates/acme-v02.api.letsencrypt.org-directory/${domain}"
+   folder_out='/etc/opt/simplex'
+   key_name='web.key'
+   cert_name='web.crt'
+
+   # Copy certificate from Caddy directory to smp-server directory
+   cp "${folder_in}/${domain}.crt" "${folder_out}/${cert_name}"
+   # Assign correct permissions
+   chown "$user":"$group" "${folder_out}/${cert_name}"
+
+   # Copy certificate key from Caddy directory to smp-server directory
+   cp "${folder_in}/${domain}.key" "${folder_out}/${key_name}"
+   # Assign correct permissions
+   chown "$user":"$group" "${folder_out}/${key_name}"
+   ```
+
+6. Make the script executable and execute it:
+
+   ```sh
+   chmod +x /usr/local/bin/simplex-servers-certs && /usr/local/bin/simplex-servers-certs
+   ```
+
+7. Check if certificates were copied:
+
+   ```sh
+   ls -haltr /etc/opt/simplex/web*
+   ```
+
+8. Create cronjob to copy certificates to smp directory in timely manner:
+
+   ```sh
+   sudo crontab -e
+   ```
+
+   ```sh
+   # Every week on 00:20 sunday
+   20 0 * * 0 /usr/local/bin/simplex-servers-certs
+   ```
+
+9. Then:
+
+   - If you're running at least `v6.1.0-beta.2`, [restart the server](#systemd-commands).
+   - If you're running below `v6.1.0-beta.2`, [upgrade the server](#updating-your-smp-server).
+
+10. Access the webpage you've deployed from your browser (`https://smp.example.org`). You should see the smp-server information that you've provided in your ini file.
+
+## Name resolution
+
+SimpleX public names (like `alice.simplex`) resolve to contact and channel addresses. These records are stored in the SimpleX Namespace registry contracts on Ethereum, so resolving a name means reading from an Ethereum node. Read more about [SimpleX Public Names](https://simplex.chat/docs/protocol/names-overview.md).
+
+With the `[NAMES]` section enabled, your smp-server resolves names for the clients connected to it: it forwards their lookups to a local REST resolver and returns the addresses. Resolution is off by default and requires running a resolver stack (an Ethereum node plus the resolver service), which needs:
+
+- 300 GB or more of NVMe SSD (TLC, not QLC, which stalls during sync)
+- 32 GB RAM and a fast multi-core CPU
+- about one day for the initial Ethereum sync
+
+### 1. Deploy the resolver stack
+
+The resolver stack (a reth + nimbus Ethereum node plus the resolver service) ships in [`scripts/resolver`](https://github.com/simplex-chat/simplexmq/tree/master/scripts/resolver) and starts with one command. See its [README](https://github.com/simplex-chat/simplexmq/blob/master/scripts/resolver/README.md) for details.
+
+```sh
+git clone https://github.com/simplex-chat/simplexmq
+cd simplexmq/scripts/resolver
+docker compose up -d
+```
+
+The shipped `.env` targets Ethereum mainnet and needs no changes. Open the peer-to-peer ports so the node can sync:
+
+```sh
+ufw allow 30303 &&\
+ufw allow 9000
+```
+
+The resolver returns errors until the node finishes syncing, which takes about a day.
+
+### 2. Check the resolver
+
+Once synced, confirm the resolver is healthy and resolves a name:
+
+```sh
+curl -s http://127.0.0.1:8000/health
+curl -s http://127.0.0.1:8000/resolve/foobar.testing
+```
+
+The first should report `"ok": true`. The second should return the records for the test name `foobar.testing`.
+
+### 3. Point smp-server at the resolver
+
+In `/etc/opt/simplex/smp-server.ini`, set the `[NAMES]` section:
+
+```ini
+[NAMES]
+enable: on
+resolver_endpoint: http://127.0.0.1:8000
+```
+
+No authentication is needed while smp-server and the resolver share a host over loopback. Behind a TLS reverse proxy on another host, use its HTTPS address and add credentials (`resolver_auth` over plain `http` is only allowed for loopback):
+
+```ini
+[NAMES]
+enable: on
+resolver_endpoint: https://names.example.com:443
+resolver_auth: basic <username>:<password>
+```
+
+### 4. Restart smp-server
+
+```sh
+systemctl restart smp-server
+```
+
+The server logs the resolver status on start:
+
+```
+[NAMES] resolver enabled, endpoint=http://127.0.0.1:8000
+[NAMES] endpoint probe ok
+```
+
+If the node is still syncing the server starts anyway, and name lookups fail until the resolver is ready.
+
+## Documentation
+
+All necessary files for `smp-server` are located in `/etc/opt/simplex/` folder.
+
+Stored messages, connections, statistics and server log are located in `/var/opt/simplex/` folder.
+
+### SMP server address
+
+SMP server address has the following format:
+
+```
+smp://<fingerprint>[:<password>]@<public_hostname>[,<onion_hostname>]
+```
+
+- `<fingerprint>`
+
+  Your `smp-server` fingerprint of certificate. You can check your certificate fingerprint in `/etc/opt/simplex/fingerprint`.
+
+- **optional** `<password>`
+
+  Your configured password of `smp-server`. You can check your configured password in `/etc/opt/simplex/smp-server.ini`, under `[AUTH]` section in `create_password:` field.
+
+- `<public_hostname>`, **optional** `<onion_hostname>`
+
+  Your configured hostname(s) of `smp-server`. You can check your configured hosts in `/etc/opt/simplex/smp-server.ini`, under `[TRANSPORT]` section in `host:` field.
+
+### Systemd commands
+
+To start `smp-server` on host boot, run:
+
+```sh
+sudo systemctl enable smp-server.service
+
+Created symlink /etc/systemd/system/multi-user.target.wants/smp-server.service → /etc/systemd/system/smp-server.service.
+```
+
+To start `smp-server`, run:
+
+```sh
+sudo systemctl start smp-server.service
+```
+
+To check status of `smp-server`, run:
+
+```sh
+sudo systemctl status smp-server.service
+
+● smp-server.service - SMP server
+     Loaded: loaded (/etc/systemd/system/smp-server.service; enabled; vendor preset: enabled)
+     Active: active (running) since Sat 2022-11-23 19:23:21 UTC; 1min 48s ago
+   Main PID: 30878 (smp-server)
+     CGroup: /docker/5588ab759e80546b4296a7c50ffebbb1fb7b55b8401300e9201313b720989aa8/system.slice/smp-server.service
+             └─30878 smp-server start
+
+Nov 23 19:23:21 5588ab759e80 systemd[1]: Started SMP server.
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: SMP server v3.4.0
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Store log: /var/opt/simplex/smp-server-store.log
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Listening on port 5223 (TLS)...
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: not expiring inactive clients
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: creating new queues requires password
+```
+
+To stop `smp-server`, run:
+
+```sh
+sudo systemctl stop smp-server.service
+```
+
+To check tail of `smp-server` log, run:
+
+```sh
+sudo journalctl -fu smp-server.service
+
+Nov 23 19:23:21 5588ab759e80 systemd[1]: Started SMP server.
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: SMP server v3.4.0
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Fingerprint: d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Server address: smp://d5fcsc7hhtPpexYUbI2XPxDbyU2d3WsVmROimcL90ss=:V8ONoJ6ICwnrZnTC_QuSHfCEYq53uLaJKQ_oIC6-ve8=@<hostnames>
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Store log: /var/opt/simplex/smp-server-store.log
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: Listening on port 5223 (TLS)...
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: not expiring inactive clients
+Nov 23 19:23:21 5588ab759e80 smp-server[30878]: creating new queues requires password
+```
+
+### Control port
+
+Enabling control port in the configuration allows administrator to see information about the smp-server in real-time. Additionally, it allows to delete queues for content moderation and see the debug info about the clients, sockets, etc. Enabling the control port requires setting the `admin` and `user` passwords.
+
+1. Generate two passwords for each user:
+
+   ```sh
+   tr -dc A-Za-z0-9 </dev/urandom | head -c 20; echo
+   ```
+
+2. Open the configuration file:
+
+   ```sh
+   vim /etc/opt/simplex/smp-server.ini
+   ```
+
+2. Configure the control port and replace the passwords:
+
+   ```ini
+   [AUTH]
+   control_port_admin_password: <your_randomly_generated_admin_password>
+   control_port_user_password: <your_randomly_generated_user_password>
+
+   [TRANSPORT]
+   control_port: 5224
+   ```
+
+3. Restart the server:
+
+   ```sh
+   systemctl restart smp-server
+   ```
+
+To access the control port, use:
+
+```sh
+nc 127.0.0.1 5224
+```
+
+or:
+
+```sh
+telnet 127.0.0.1 5224
+```
+
+Upon connecting, the control port should print:
+
+```sh
+SMP server control port
+'help' for supported commands
+```
+
+To authenticate, type the following and hit enter. Change the `my_generated_password` with the `user` or `admin` password from the configuration:
+
+```sh
+auth my_generated_password
+```
+
+Here's the full list of commands, their descriptions and who can access them.
+
+| Command          | Description                                                                     | Requires `admin` role      |
+| ---------------- | ------------------------------------------------------------------------------- | -------------------------- |
+| `stats`          | Real-time statistics. Fields described in [Daily statistics](#daily-statistics) | -                          |
+| `stats-rts`      | GHC/Haskell statistics. Can be enabled with `+RTS -T -RTS` option               | -                          |
+| `clients`        | Clients information. Useful for debugging.                                      | yes                        |
+| `sockets`        | General sockets information.                                                    | -                          |
+| `socket-threads` | Thread information per socket. Useful for debugging.                             | yes                        |
+| `threads`        | Threads information. Useful for debugging.                                      | yes                        |
+| `server-info`    | Aggregated server information.                                                   | -                          |
+| `delete`         | Delete known queue. Useful for content moderation.                              | -                          |
+| `save`           | Save queues/messages from memory.                                               | yes                        |
+| `help`           | Help menu.                                                                      | -                          |
+| `quit`           | Exit the control port.                                                          | -                          |
+
+### Daily statistics
+
+You can enable `smp-server` statistics for `Grafana` dashboard by setting value `on` in `/etc/opt/simplex/smp-server.ini`, under `[STORE_LOG]` section in `log_stats:` field.
+
+Logs will be stored as `csv` file in `/var/opt/simplex/smp-server-stats.daily.log`. Fields for the `csv` file are:
+
+```sh
+fromTime,qCreated,qSecured,qDeleted,msgSent,msgRecv,dayMsgQueues,weekMsgQueues,monthMsgQueues,msgSentNtf,msgRecvNtf,dayCountNtf,weekCountNtf,monthCountNtf,qCount,msgCount,msgExpired,qDeletedNew,qDeletedSecured,pRelays_pRequests,pRelays_pSuccesses,pRelays_pErrorsConnect,pRelays_pErrorsCompat,pRelays_pErrorsOther,pRelaysOwn_pRequests,pRelaysOwn_pSuccesses,pRelaysOwn_pErrorsConnect,pRelaysOwn_pErrorsCompat,pRelaysOwn_pErrorsOther,pMsgFwds_pRequests,pMsgFwds_pSuccesses,pMsgFwds_pErrorsConnect,pMsgFwds_pErrorsCompat,pMsgFwds_pErrorsOther,pMsgFwdsOwn_pRequests,pMsgFwdsOwn_pSuccesses,pMsgFwdsOwn_pErrorsConnect,pMsgFwdsOwn_pErrorsCompat,pMsgFwdsOwn_pErrorsOther,pMsgFwdsRecv,qSub,qSubAuth,qSubDuplicate,qSubProhibited,msgSentAuth,msgSentQuota,msgSentLarge,msgNtfs,msgNtfNoSub,msgNtfLost,qSubNoMsg,msgRecvGet,msgGet,msgGetNoMsg,msgGetAuth,msgGetDuplicate,msgGetProhibited,psSubDaily,psSubWeekly,psSubMonthly,qCount2,ntfCreated,ntfDeleted,ntfSub,ntfSubAuth,ntfSubDuplicate,ntfCount,qDeletedAllB,qSubAllB,qSubEnd,qSubEndB,ntfDeletedB,ntfSubB,msgNtfsB,msgNtfExpired
+```
+
+**Fields description**
+
+| Field number  | Field name                   | Field Description          |
+| ------------- | ---------------------------- | -------------------------- |
+| 1             | `fromTime`                   | Date of statistics         |
+| Messaging queue:                                                          |
+| 2             | `qCreated`                   | Created                    |
+| 3             | `qSecured`                   | Established                |
+| 4             | `qDeleted`                   | Deleted                    |
+| Messages:                                                                 |
+| 5             | `msgSent`                    | Sent                       |
+| 6             | `msgRecv`                    | Received                   |
+| 7             | `dayMsgQueues`               | Active queues in a day     |
+| 8             | `weekMsgQueues`              | Active queues in a week    |
+| 9             | `monthMsgQueues`             | Active queues in a month   |
+| Messages with "notification" flag                                         |
+| 10            | `msgSentNtf`                 | Sent                       |
+| 11            | `msgRecvNtf`                 | Received                   |
+| 12            | `dayCountNtf`                | Active queues in a day     |
+| 13            | `weekCountNtf`               | Active queues in a week    |
+| 14            | `monthCountNtf`              | Active queues in a month   |
+| Additional statistics:                                                    |
+| 15            | `qCount`                     | Stored queues              |
+| 16            | `msgCount`                   | Stored messages            |
+| 17            | `msgExpired`                 | Expired messages           |
+| 18            | `qDeletedNew`                | New deleted queues         |
+| 19            | `qDeletedSecured`            | Secured deleted queues     |
+| Requested sessions with all relays:                                       |
+| 20            | `pRelays_pRequests`          | - requests                 |
+| 21            | `pRelays_pSuccesses`         | - successes                |
+| 22            | `pRelays_pErrorsConnect`     | - connection errors        |
+| 23            | `pRelays_pErrorsCompat`      | - compatibility errors     |
+| 24            | `pRelays_pErrorsOther`       | - other errors             |
+| Requested sessions with own relays:                                       |
+| 25            | `pRelaysOwn_pRequests`       | - requests                 |
+| 26            | `pRelaysOwn_pSuccesses`      | - successes                |
+| 27            | `pRelaysOwn_pErrorsConnect`  | - connection errors        |
+| 28            | `pRelaysOwn_pErrorsCompat`   | - compatibility errors     |
+| 29            | `pRelaysOwn_pErrorsOther`    | - other errors             |
+| Message forwards to all relays:                                           |
+| 30            | `pMsgFwds_pRequests`         | - requests                 |
+| 31            | `pMsgFwds_pSuccesses`        | - successes                |
+| 32            | `pMsgFwds_pErrorsConnect`    | - connection errors        |
+| 33            | `pMsgFwds_pErrorsCompat`     | - compatibility errors     |
+| 34            | `pMsgFwds_pErrorsOther`      | - other errors             |
+| Message forward to own relays:                                            |
+| 35            | `pMsgFwdsOwn_pRequests`      | - requests                 |
+| 36            | `pMsgFwdsOwn_pSuccesses`     | - successes                |
+| 37            | `pMsgFwdsOwn_pErrorsConnect` | - connection errors        |
+| 38            | `pMsgFwdsOwn_pErrorsCompat`  | - compatibility errors     |
+| 39            | `pMsgFwdsOwn_pErrorsOther`   | - other errors             |
+| Received message forwards:                                                |
+| 40            | `pMsgFwdsRecv`               |                            |
+| Message queue subscription errors:                                        |
+| 41            | `qSub`                       | All                        |
+| 42            | `qSubAuth`                   | Authentication errors      |
+| 43            | `qSubDuplicate`              | Duplicate SUB errors       |
+| 44            | `qSubProhibited`             | Prohibited SUB errors      |
+| Message errors:                                                           |
+| 45            | `msgSentAuth`                | Authentication errors      |
+| 46            | `msgSentQuota`               | Quota errors               |
+| 47            | `msgSentLarge`               | Large message errors       |
+| 48            | `msgNtfs`                    | XXXXXXXXXXXXXXXXXXXX       |
+| 49            | `msgNtfNoSub`                | XXXXXXXXXXXXXXXXXXXX       |
+| 50            | `msgNtfLost`                 | XXXXXXXXXXXXXXXXXXXX       |
+| 51            | `qSubNoMsg`                  | Removed, always 0          |
+| 52            | `msgRecvGet`                 | XXXXXXXXXXXXXXXXX          |
+| 53            | `msgGet`                     | XXXXXXXXXXXXXXXXX          |
+| 54            | `msgGetNoMsg`                | XXXXXXXXXXXXXXXXX          |
+| 55            | `msgGetAuth`                 | XXXXXXXXXXXXXXXXX          |
+| 56            | `msgGetDuplicate`            | XXXXXXXXXXXXXXXXX          |
+| 57            | `msgGetProhibited`           | XXXXXXXXXXXXXXXXX          |
+| 58            | `psSub_dayCount`             | Removed, always 0          |
+| 59            | `psSub_weekCount`            | Removed, always 0          |
+| 60            | `psSub_monthCount`           | Removed, always 0          |
+| 61            | `qCount`                     | XXXXXXXXXXXXXXXXX          |
+| 62            | `ntfCreated`                 | XXXXXXXXXXXXXXXXX          |
+| 63            | `ntfDeleted`                 | XXXXXXXXXXXXXXXXX          |
+| 64            | `ntfSub`                     | XXXXXXXXXXXXXXXXX          |
+| 65            | `ntfSubAuth`                 | XXXXXXXXXXXXXXXXX          |
+| 66            | `ntfSubDuplicate`            | XXXXXXXXXXXXXXXXX          |
+| 67            | `ntfCount`                   | XXXXXXXXXXXXXXXXX          |
+| 68            | `qDeletedAllB`               | XXXXXXXXXXXXXXXXX          |
+| 69            | `qSubAllB`                   | XXXXXXXXXXXXXXXXX          |
+| 70            | `qSubEnd`                    | XXXXXXXXXXXXXXXXX          |
+| 71            | `qSubEndB`                   | XXXXXXXXXXXXXXXXX          |
+| 72            | `ntfDeletedB`                | XXXXXXXXXXXXXXXXX          |
+| 73            | `ntfSubB`                    | XXXXXXXXXXXXXXXXX          |
+| 74            | `msgNtfsB`                   | XXXXXXXXXXXXXXXXX          |
+| 75            | `msgNtfExpired`              | XXXXXXXXXXXXXXXXX          |
+
+To import `csv` to `Grafana` one should:
+
+1. Install Grafana plugin: [Grafana - CSV datasource](https://grafana.com/grafana/plugins/marcusolsson-csv-datasource/)
+
+2. Allow local mode by appending following:
+
+   ```sh
+   [plugin.marcusolsson-csv-datasource]
+   allow_local_mode = true
+   ```
+
+   ... to `/etc/grafana/grafana.ini`
+
+3. Add a CSV data source:
+
+   - In the side menu, click the Configuration tab (cog icon)
+   - Click Add data source in the top-right corner of the Data Sources tab
+   - Enter "CSV" in the search box to find the CSV data source
+   - Click the search result that says "CSV"
+   - In URL, enter a file that points to CSV content
+
+4. You're done! You should be able to create your own dashboard with statistics.
+
+For further documentation, see: [CSV Data Source for Grafana - Documentation](https://grafana.github.io/grafana-csv-datasource/)
+
+## Updating your SMP server
+
+To update your smp-server to latest version, choose your installation method and follow the steps:
+
+   - Manual deployment
+
+     1. Stop the server:
+
+        ```sh
+        sudo systemctl stop smp-server
+        ```
+
+     2. Update the binary:
+
+        ```sh
+         curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/smp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/smp-server && chmod +x /usr/local/bin/smp-server
+        ```
+
+     3. Start the server:
+
+        ```sh
+        sudo systemctl start smp-server
+        ```
+
+   - [Official installation script](https://github.com/simplex-chat/simplexmq#using-installation-script)
+
+     1. Execute the following command:
+
+        ```sh
+        sudo simplex-servers-update
+        ```
+
+        To install specific version, run:
+
+        ```sh
+        export VER=<version_from_github_releases> &&\
+        sudo -E simplex-servers-update
+        ```
+
+     2. Done!
+
+   - [Docker container](https://github.com/simplex-chat/simplexmq#using-docker)
+
+     1. Stop and remove the container:
+
+        ```sh
+        docker rm $(docker stop $(docker ps -a -q --filter ancestor=simplexchat/smp-server --format="\{\{.ID\}\}"))
+        ```
+
+     2. Pull latest image:
+
+        ```sh
+        docker pull simplexchat/smp-server:latest
+        ```
+
+     3. Start new container:
+
+        ```sh
+        docker run -d \
+          -p 5223:5223 \
+          -p 443:443 \
+          -v $HOME/simplex/smp/config:/etc/opt/simplex:z \
+          -v $HOME/simplex/smp/logs:/var/opt/simplex:z \
+          simplexchat/smp-server:latest
+        ```
+
+   - [Linode Marketplace](https://www.linode.com/marketplace/apps/simplex-chat/simplex-chat/)
+
+     1. Pull latest images:
+
+        ```sh
+        docker-compose --project-directory /etc/docker/compose/simplex pull
+        ```
+
+     2. Restart the containers:
+
+        ```sh
+        docker-compose --project-directory /etc/docker/compose/simplex up -d --remove-orphans
+        ```
+
+     3. Remove obsolete images:
+
+        ```sh
+        docker image prune
+        ```
+
+## Reproduce builds
+
+You can locally reproduce server binaries, following these instructions.
+
+If you are a security expert or researcher, you can help SimpleX network and users community by signing the release checksums – we will [publish your signature](https://github.com/simplex-chat/simplexmq/releases/tag/v6.3.1). Please reach out to us!
+
+To reproduce the build you must have:
+
+- Linux machine
+- `x86-64` architecture
+- Installed `docker`, `curl` and `git`
+
+1. Download script:
+
+   ```sh
+   curl -LO 'https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/master/scripts/simplexmq-reproduce-builds.sh'
+   ```
+
+2. Make it executable:
+
+   ```sh
+   chmod +x simplexmq-reproduce-builds.sh
+   ```
+
+3. Execute the script with the required tag:
+
+   ```sh
+   ./simplexmq-reproduce-builds.sh 'v6.3.1'
+   ```
+
+   The script executes these steps (please review the script to confirm):
+
+   1) builds all server binaries for the release in docker container.
+   2) downloads binaries from the same GitHub release and compares them with the built binaries.
+   3) if they all match, generates _sha256sums file with their checksums.
+
+   This will take a while.
+
+4. After compilation, you should see the folder named as the tag (e.g., `v6.3.1`) with two subfolders:
+
+   ```sh
+   ls v6.3.1
+   ```
+
+   ```sh
+   from-source  prebuilt  _sha256sums
+   ```
+
+   The file _sha256sums contains the hashes of all builds - you can compare it with the same file in GitHub release.
+
+## Configuring the app to use the server
+
+To configure the app to use your messaging server copy its full address, including password, and add it to the app. You have an option to use your server together with preset servers or without them - you can remove or disable them.
+
+It is also possible to share the address of your server with your friends by letting them scan QR code from server settings - it will include server password, so they will be able to receive messages via your server as well.
+
+_Please note_: you need SMP server version 4.0 to have password support. If you already have a deployed server, you can add password by adding it to server INI file.
+
+<img src="./server_config_1.png" width="288">    <img src="./server_config_2.png" width="288">    <img src="./server_config_3.png" width="288">
diff --git a/docs/simplex.html b/docs/simplex.html
index b9867e1d4f..ce1ed8ba5b 100644
--- a/docs/simplex.html
+++ b/docs/simplex.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/simplex.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/simplex.md b/docs/simplex.md
new file mode 100644
index 0000000000..81c6911ce3
--- /dev/null
+++ b/docs/simplex.md
@@ -0,0 +1,97 @@
+| Updated 07.02.2023 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/simplex.html), [CZ](https://simplex.chat/docs/lang/cs/simplex.html), [PL](https://simplex.chat/docs/lang/pl/simplex.html) |
+# SimpleX platform - motivation and comparison
+
+## Problems
+
+Existing chat platforms and protocols have some or all of the following problems:
+
+- Lack of privacy of the user profile and contacts (meta-data privacy).
+- No protection (or only optional protection) of [E2EE][1] implementations from MITM attacks via provider.
+- Unsolicited messages (spam and abuse).
+- Lack of data ownership and protection.
+- Complexity of usage for all non-centralized protocols to non-technical users.
+
+The concentration of the communication in a small number of centralized platforms makes resolving these problems quite difficult.
+
+## Proposed solution
+
+Proposed stack of protocols solves these problems by making both messages and contacts stored only on client devices, reducing the role of the servers to simple message relays that only require authorization of messages sent to the queues, but do NOT require user authentication - not only the messages but also the metadata is protected because users do not have any identifiers assigned to them - unlike with any other platforms.
+
+See [SimpleX whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md) for more information on platform objectives and technical design.
+
+## Why use SimpleX
+
+## SimpleX unique approach to privacy and security
+
+Everyone should care about privacy and security of their communications - even ordinary conversations can put you in danger.
+
+### Full privacy of your identity, profile, contacts and metadata
+
+**Unlike any other existing messaging platform, SimpleX has no identifiers assigned to the users** - it does not use phone numbers (like Signal or WhatsApp), domain-based addresses (like email, XMPP or Matrix), usernames (like Telegram), public keys or even random numbers (like all other messengers) to identify its users - we do not even know how many people use SimpleX.
+
+To deliver the messages instead of user identifiers that all other platforms use, SimpleX uses the addresses of unidirectional (simplex) message queues. Using SimpleX is like having a different email address or a phone number for each contact you have, but without the hassle of managing all these addresses. In the near future SimpleX apps will also change the message queues automatically, moving the conversations from one server to another, to provide even better privacy to the users.
+
+This approach protects the privacy of who are you communicating with, hiding it from SimpleX platform servers and from any observers. You can further improve your privacy by configuring your network access to connect to SimpleX servers via some overlay transport network, e.g. Tor.
+
+### The best protection against spam and abuse
+
+As you have no identifier on SimpleX platform, you cannot be contacted unless you share a one-time invitation link or an optional temporary user address. Even with the optional user addresses, while they can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+### Complete ownership, control and security of your data
+
+SimpleX stores all user data on client devices, the messages are only held temporarily on SimpleX relay servers until they are received.
+
+We use portable database format that can be used on all supported devices - we will soon add the ability to export the chat database from the mobile app so it can be used on another device.
+
+Unlike servers of federated networks (email, XMPP or Matrix), SimpleX servers do not store user accounts, they simply relay messages to the recipients, protecting the privacy of both parties. There are no identifiers or encrypted messages in common between sent and received traffic of the server, thanks to the additional encryption layer for delivered messages. So if anybody is observing server traffic, they cannot easily determine who is communicating with whom (see [SimpleX whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md) for the known traffic correlation attacks).
+
+### Users own SimpleX network
+
+You can use SimpleX with your own servers and still communicate with people using the servers that are pre-configured in the apps or any other SimpleX servers.
+
+SimpleX platform uses an open protocol and provides SDK to create chat bots, allowing implementation of services that users can interact with via SimpleX Chat apps – we are really looking forward to see what SimpleX services can be built.
+
+If you are considering developing with the SimpleX platform, whether for chat bot services for SimpleX app users or to integrate the SimpleX Chat library into your mobile apps, please get in touch for any advice and support.
+
+## Comparison with other protocols
+
+|                                                |    SimpleX chat    | Signal, big platforms |  XMPP, Matrix   |  P2P protocols  |
+| :--------------------------------------------- | :----------------: | :-------------------: | :-------------: | :-------------: |
+| Requires user identifiers                      |    No = private    |    Yes<sup>1</sup>    | Yes<sup>2</sup> | Yes<sup>3</sup> |
+| Possibility of MITM                            |    No = secure     |    Yes<sup>4</sup>    |       Yes       |       Yes       |
+| Dependence on DNS                              |   No = resilient   |          Yes          |       Yes       |       No        |
+| Single operator or network                     | No = decentralized |          Yes          |       No        | Yes<sup>5</sup> |
+| Central component or other network-wide attack |   No = resilient   |          Yes          | Yes<sup>2</sup> | Yes<sup>6</sup> |
+
+1. Usually based on a phone number, in some cases on usernames.
+2. DNS based.
+3. Public key or some other globally unique ID.
+4. If operator’s servers are compromised.
+5. While P2P networks and cryptocurrency-based networks are distributed, they are not decentralized - they operate as a single network, with a single namespace of user addresses.
+6. P2P networks either have a central authority or the whole network can be compromised - see the next section.
+
+## Comparison with [P2P][9] messaging protocols
+
+There are several P2P chat/messaging protocols and implementations that aim to solve privacy and centralisation problem, but they have their own set of problems that makes them less reliable than the proposed design, more complex to implement and analyse and more vulnerable to attacks.
+
+1. [P2P][9] networks use some variant of [DHT][10] to route messages/requests through the network. DHT implementations have complex designs that have to balance reliability, delivery guarantee and latency. The proposed design has both better delivery guarantees and lower latency (the message is passed multiple times in parallel, through one node each time, using servers chosen by the recipient, while in P2P networks the message is passed through `O(log N)` nodes sequentially, using nodes chosen by the algorithm).
+
+2. The proposed design, unlike most P2P networks, has no global user identifiers of any kind, even temporary.
+
+3. P2P itself does not solve [MITM attack][2] problem, and most existing solutions do not use out-of-band messages for the initial key exchange. The proposed design uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent][11]). The proposed design is transport agnostic - it can work over standard web protocols, and the servers can be deployed on the same domains as the websites.
+
+5. All known P2P networks are likely to be vulnerable to [Sybil attack][12], because each node is discoverable, and the network operates as a whole. Known measures to reduce the probability of the Sybil attack either require a centralized component or expensive [proof of work][13]. The proposed design, on the opposite, has no server discoverability - servers are not connected, not known to each other and to all clients. The SimpleX network is fragmented and operates as multiple isolated connections. It makes network-wide attacks on SimpleX network impossible - even if some servers are compromised, other parts of the network can operate normally, and affected clients can switch to using other servers without losing contacts or messages.
+
+6. P2P networks are likely to be [vulnerable][14] to [DRDoS attack][15]. In the proposed design clients only relay traffic from known trusted connections and cannot be used to reflect and amplify the traffic in the whole network.
+
+[1]: https://en.wikipedia.org/wiki/End-to-end_encryption
+[2]: https://en.wikipedia.org/wiki/Man-in-the-middle_attack
+[9]: https://en.wikipedia.org/wiki/Peer-to-peer
+[10]: https://en.wikipedia.org/wiki/Distributed_hash_table
+[11]: https://en.wikipedia.org/wiki/BitTorrent
+[12]: https://en.wikipedia.org/wiki/Sybil_attack
+[13]: https://en.wikipedia.org/wiki/Proof_of_work
+[14]: https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent
+[15]: https://en.wikipedia.org/wiki/Denial-of-service_attack#Reflected_attack
diff --git a/docs/themes.html b/docs/themes.html
index afdf320baf..de91b36dc3 100644
--- a/docs/themes.html
+++ b/docs/themes.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/themes.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/themes.md b/docs/themes.md
new file mode 100644
index 0000000000..939e8b6858
--- /dev/null
+++ b/docs/themes.md
@@ -0,0 +1,25 @@
+# App color themes
+
+Mobile apps allow to configure, export and import color themes. Currently this is only supported in Android app.
+
+You can contribute your themes to the repository by creating a pull request.
+
+## How to contribute a theme
+
+1. Once you have configured your theme in the app, export it to a file and give it a descriptive name – e.g., `example.theme`
+
+2. Export your app database, and import a [sample chat database](themes/simplex-chat.sample.zip) - the passphrase is `passphrase`.
+
+3. Make three screenshots - the list of conversations with opened profile picker, conversation and privacy settings.
+
+4. Create PR that includes these files and amends this THEMES.md file, following the example below.
+
+5. Restore your database from the backup.
+
+## Color themes
+
+### SimpleX - included dark blue theme
+
+Download [SimpleX theme](themes/example.theme)
+
+<img src="./themes/example-chats.png" width="240">    <img src="./themes/example-conversation.png" width="240">    <img src="./themes/example-settings.png" width="240">
diff --git a/docs/trademark.html b/docs/trademark.html
index 612e5d9df2..30b15c5a7f 100644
--- a/docs/trademark.html
+++ b/docs/trademark.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/trademark.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/trademark.md b/docs/trademark.md
new file mode 100644
index 0000000000..727e65fff1
--- /dev/null
+++ b/docs/trademark.md
@@ -0,0 +1,33 @@
+# SimpleX Chat Trademark Policy
+
+The SimpleX Chat name and logo are trademarks of SimpleX Chat Ltd. This policy protects the brand from confusion. All uses must follow both the context rules (permitted/prohibited) and usage guidelines below. Unauthorized uses require written permission.
+
+## Permitted Contexts
+
+- **Communities/Events**: For unofficial groups or events.
+- **Addresses/Entities**: To indicate a SimpleX address, person, business, or community.
+- **Publications**: In articles, blogs, videos, social media posts and presentations about SimpleX Chat or SimpleX network.
+- **Software Descriptions**: To state compatibility, e.g., "Compatible with SimpleX network", in docs or descriptions (not in software name/branding).
+
+## Prohibited Contexts
+
+- **Software Branding**: As part of any software's name, branding, or logo, including forks.
+- **Implied Affiliation**: Suggesting endorsement, sponsorship, or official ties without permission.
+- **Commercial Activities**: In ads, merchandise, or promotions without permission.
+- **Any Other**: Uses not listed as permitted.
+
+## Usage Guidelines
+
+When using in permitted contexts:
+- Include "Unofficial" for communities/events.
+- Use logo unchanged (shape/colors), except grayscale if needed.
+- Use icon or icon with "SimpleX" word. See logos [here](https://github.com/simplex-chat/simplex-chat/blob/stable/media-logos).
+- Avoid modifications or implications of official status.
+
+## General Terms
+
+We reserve all trademark rights. For permissions, contact us via email or SimpleX. We may enforce against violations. Policy updates posted here.
+
+## Note
+
+SimpleX Chat software is licensed under AGPLv3 - see [LICENSE](https://github.com/simplex-chat/simplex-chat/blob/stable/LICENSE). This policy covers only trademarks, not code use.
diff --git a/docs/translations.html b/docs/translations.html
index c96e838112..e69f75e506 100644
--- a/docs/translations.html
+++ b/docs/translations.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/translations.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/translations.md b/docs/translations.md
new file mode 100644
index 0000000000..7f8e57a279
--- /dev/null
+++ b/docs/translations.md
@@ -0,0 +1,99 @@
+| 19.03.2023 | EN, [CZ](https://simplex.chat/docs/lang/cs/translations.html), [FR](https://simplex.chat/docs/lang/fr/translations.html), [PL](https://simplex.chat/docs/lang/pl/translations.html) |
+
+# Contributing translations to SimpleX Chat
+
+Huge thanks for your interest in translating SimpleX Chat - it helps a lot to make it accessible to a wider range of users, and we really appreciate your help.
+
+It requires a substantial time investment - most people underestimate it initially - and ongoing maintenance as we develop the application.
+
+This document is created to speed up this process, and share some important "gotchas" we've discovered while working with Weblate - the platform we use for interface translations.
+
+## Before you start translation
+
+1. Create an account in Weblate, using the same email that you use in GitHub - it will make your contributions associated with your GitHub account, and might help you in some cases. Once translation is released to the users we will add your account name to the [list of translators](https://github.com/simplex-chat/simplex-chat#translate-the-apps), unless you ask us not to do it.
+
+2. Before you start the translation there is a simple contributor license agreement to sign via Weblate - this is to avoid any conflicts around IP rights. The copy of this agreement is also [available here](https://github.com/simplex-chat/cla/blob/master/CLA.md).
+
+3. We can also add you to the group of translators for any questions and updates - please connect to the developers via chat (when you just install the app or later, via "Send questions and ideas" in the app settings).
+
+## Translation process
+
+It's easier to translate Android app first, and then iOS app, as Android app strings are set up as a glossary for iOS.
+
+The steps are:
+
+1. [You translate Android app](#translating-android-app) in Weblate.
+2. [We review and release Android app translations](#releasing-android-app-translations).
+3. You review translations in the app and correct any mistakes.
+4. [You translate iOS app in Weblate](#translating-ios-app)
+5. We review and release iOS app translations.
+
+### Translating Android app
+
+1. Please start from [Android app](https://hosted.weblate.org/projects/simplex-chat/android/), both when you do the most time-consuming initial translation, and add any strings later. Firstly, iOS strings can be a bit delayed from appearing in Weblate, as it requires a manual step from us before they are visible. Secondly, Android app is set up as a glossary for iOS app, and 2/3 of all strings require just two clicks to transfer them from Android to iOS (it still takes some time, Weblate doesn't automate it, unfortunately).
+
+2. Some of the strings do not need translations, but they still need to be copied over - there is a button in weblate UI for that:
+
+<img src="./images/weblate_1.png" alt="weblate: copy source to translation" width="100%">
+
+3. Weblate also has automatic suggestions that can speed up the process. Sometimes they can be used as is, sometimes they need some editing - click to use them in translations.
+
+4. Also, please note the string Key (it's on the right of the screen) - it may give you a hint about what this string means when unclear. E.g., the key for "Additional accent" (not clear) is "color_primary_variant" (a bit more clear that it refers to a color used in the app).
+
+5. Once all strings in Android app are translated, please review it to ensure consistent style and language, so that the same words are consistently used for similar user actions, same as in English. Sometimes, you will have to use different words in cases when English has just one, please try to use these choices consistently in similar contexts, to make it easier for the end users.
+
+Please also review reverse translations using Chrome browser and *Translate to English* feature in the _Browse_ mode of weblate - this is what we will be reviewing before translations are released. Fix any mistakes, and please add comments in cases when a sufficiently different translations are justified - it will make review much faster.
+
+### Releasing Android app translations
+
+Once Android app is translated, please let us know.
+
+We will then:
+  - review all the translations and suggest any corrections - it also takes a bit of time :)
+  - merge them to the source code - while we do it weblate will be locked for changes.
+  - create beta releases of both iOS and Android apps - we can also add you to the internal tester groups, so you can install the apps before anybody else.
+  - release it to our beta users - it's more than a thousand people who use our beta versions.
+  - release the app and include the new language in the announcement.
+
+### Translating iOS app
+
+1. When you translate [iOS app](https://hosted.weblate.org/projects/simplex-chat/ios/), a large part of the strings are exactly the same - they can be copied over in one click in glossary section. The visual hint that it can be done is that the whole source string is highlighted in yellow. Many other strings are very similar, they only differ in interpolation syntax or how bold font is used - they require minimal editing. There are some strings that are unique to iOS platform - they need to be translated separately
+
+2. Please review iOS translations in the same way as Android and let us know when it's ready for review - we will repeat the same process for iOS app.
+
+Thanks a lot! This is a huge effort and a huge help for SimpleX Network to grow.
+
+<img src="./images/weblate_2.png" alt="weblate: automatic suggestions" width="100%">
+
+## Common translation mistakes
+
+1. The word "chat" is used in several meanings, depending on the context. It can mean either "SimpleX Chat app" (e.g. in Start/stop chat) or "a single conversation". Please ask when it is not clear, and we will be adding more translation notes.
+
+2. Please use plural and singular as in the original strings, this may change the meaning otherwise. E.g., some settings apply to all contacts, and some to just one contact, it will be confusing if you use plural in both cases.
+
+3. The app uses "Passcode" to provide access, not "password" - in many languages it is translated as "access code". The database uses "Passphrase" - in many languages it is translated as "Password". Please use these words consistently.
+
+4. Member "role". This word refers to the set of permissions the user has, it can be "owner", "admin", "member" or "observer" (the lowest permission that only allows to read messages and add message reactions). Translating it as "identity" or as "function" may be incorrect.
+
+5. "Moderate" / "moderated". These words means "to delete message of another member" and "deleted by admin" respectively. This feature is used when a member sends the message that is not appropriate for the group. Many languages have similar words.
+
+## How we review the translations
+
+To validate the correctness of the translations we review reverse translations by browsing Weblate pages in Google Chrome browser in "Translate to English" mode. E.g., to review the German translations of Android interface somebody from our team scrolled through [these 68 pages](https://hosted.weblate.org/browse/simplex-chat/android/de/).
+
+We are not looking for reverse translation being exactly the same as the original, it is rarely the case, only that it is generally correct.
+
+You would make the review much easier if you could review it in advance in the same way, and comment on any cases where reverse translations are completely different (there may be valid cases for that).
+
+## What is next
+
+1. As we update the app, we post the updates in the group of translators. You are absolutely under no obligation to translate these additional strings. We hugely appreciate if you do though, as it makes the users experience so much better when they depend on your translations, than if some new part of the app is not translated.
+
+2. You can further help SimpleX adoption in your country / language group by translating [our website](https://simplex.chat) (also [via weblate](https://hosted.weblate.org/projects/simplex-chat/website/)) and/or [GitHub documents](https://github.com/simplex-chat/simplex-chat/tree/master/docs/lang) (this is only possible via git)!
+
+3. Also, if you want to be a moderator/admin of the users group in your language, once the app is translated we can host such group - we are preparing community guidelines and adding some moderation tools to the app to be released in v4.6 in March.
+
+
+Thank you very much again for helping us grow SimpleX Chat!
+
+Evgeny, SimpleX Chat founder.
diff --git a/docs/webrtc.html b/docs/webrtc.html
index 7390b555eb..7fe1555e0c 100644
--- a/docs/webrtc.html
+++ b/docs/webrtc.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/webrtc.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/webrtc.md b/docs/webrtc.md
new file mode 100644
index 0000000000..878755f9b7
--- /dev/null
+++ b/docs/webrtc.md
@@ -0,0 +1,152 @@
+| Updated 31.01.2023 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/webrtc.html), [CZ](https://simplex.chat/docs/lang/cs/webrtc.html), [PL](https://simplex.chat/docs/lang/pl/webrtc.html) |
+
+# Using custom WebRTC ICE servers in SimpleX Chat
+
+## Deploy STUN/TURN server
+
+For this guide, we'll be using the most featureful and battle-tested STUN/TURN server implementation – [`coturn`](https://github.com/coturn/coturn) and [`Ubuntu 20.04 LTS`](https://ubuntu.com/download/server) Linux distribution.
+
+0. Obtain `stun.$YOUR_DOMAIN` and `turn.$YOUR_DOMAIN` certificates.
+
+   We're using [Let's Encrypt](https://letsencrypt.org/getting-started/).
+
+1. Install `coturn` package from the main repository.
+
+```sh
+apt update && apt install coturn
+```
+
+2. Uncomment `TURNSERVER_ENABLED=1` from `/etc/default/coturn`:
+
+```sh
+sed -i '/TURN/s/^#//g' /etc/default/coturn
+```
+
+3. Configure `coturn` in `/etc/turnserver.conf`:
+
+   Also, please see comments for each individual option.
+
+```sh
+# Also listen to 443 port for tls
+alt-tls-listening-port=443
+# Use fingerprints in the TURN messages
+fingerprint
+# Use long-term credentials mechanism
+lt-cred-mech
+# Your credentials
+user=$YOUR_LOGIN:$YOUR_PASSWORD
+# Your server domain
+server-name=$YOUR_DOMAIN
+# The default realm to be used for the users when no explicit origin/realm relationship was found
+realm=$YOUR_DOMAIN
+# Path to your certificates. Make sure they're readable by coturn process user/group
+cert=/var/lib/turn/cert.pem
+pkey=/var/lib/turn/key.pem
+# Use 2066 bits predefined DH TLS key
+dh2066
+# Log to journalctl
+syslog
+# User/group which will be running coturn service
+proc-user=turnserver
+proc-group=turnserver
+# Disable weak encryption
+no-tlsv1
+no-tlsv1_1
+no-tlsv1_2
+```
+
+4. Start and enable `coturn` service:
+
+```sh
+systemctl enable coturn && systemctl start coturn
+```
+
+5. Optionally, if using `ufw` firewall, open relevant ports:
+
+- **3478** – "plain" TURN/STUN;
+- **5349** – TURN/STUN over TLS;
+- **443** – TURN/STUN over TLS, which can bypass firewalls;
+- **49152:65535** – port range that Coturn will use by default for TURN relay.
+
+```sh
+# For Ubuntu
+sudo ufw allow 3478 && \
+sudo ufw allow 443 && \
+sudo ufw allow 5349 && \
+sudo ufw allow 49152:65535/tcp && \
+sudo ufw allow 49152:65535/udp
+
+# For Fedora
+sudo firewall-cmd --permanent --add-port=443/tcp && \
+sudo firewall-cmd --permanent --add-port=443/udp && \
+sudo firewall-cmd --permanent --add-port=5349/tcp && \
+sudo firewall-cmd --permanent --add-port=5349/udp && \
+sudo firewall-cmd --permanent --add-port=49152:65535/tcp && \
+sudo firewall-cmd --permanent --add-port=49152:65535/udp && \
+sudo firewall-cmd --reload
+```
+
+## Configure mobile apps
+
+To configure your mobile app to use your server:
+
+1. Open `Settings / Network & Servers / WebRTC ICE servers` and switch toggle `Configure ICE servers`.
+
+2. Enter all server addresses in the field, one per line, for example if your servers are on the port 5349:
+
+```
+stun:stun.example.com:5349
+turn:username:password@turn.example.com:5349
+```
+
+This is it - you now can make audio and video calls via your own server, without sharing any data with our servers (other than the key exchange with your contact in E2E encrypted messages).
+
+## Troubleshoot
+
+- **Determine if server is available**:
+
+  Run this command in your terminal:
+
+  ```sh
+  ping <your_ip_or_domain>
+  ```
+
+  If packets are being transmitted, the server is up!
+
+- **Determine if ports are open**:
+
+  Run this command in your terminal:
+
+  ```sh
+  nc -zvw10 <your_ip_or_domain> 443 5349
+  ```
+
+  You should see:
+
+  ```
+  Connection to <your_ip_or_domain> 443 port [tcp/https] succeeded!
+  Connection to <your_ip_or_domain> 5349 port [tcp/*] succeeded!
+  ```
+
+- **Test STUN/TURN connectivity**:
+
+  1. Go to [IceTest](https://icetest.info/).
+
+  2. In **Build up ICE Server List** section, add:
+
+     <img src="./stun_1.png">
+
+     - `STUN: stun:<your_ip_or_domain>:<port>` and hit `Add STUN`
+     - `TURN: turn:<your_ip_or_domain>:<port>`, `Username: <your_login>`, `Credential: <your_pass>` and hit `Add TURN`
+
+     Where `<port>` is 443 or 5349.
+
+  3. You should see your servers in **ICE server list** section. If everything is set up correctly, hit `Start test`:
+
+     <img src="./stun_2.png">
+
+  4. In **Results** section, you should see something like this:
+
+     <img src="./stun_3.png">
+
+     If results show `srflx` and `relay` candidates, everything is set up correctly!
diff --git a/docs/why.html b/docs/why.html
index d61b06170b..5bd774a694 100644
--- a/docs/why.html
+++ b/docs/why.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
@@ -875,6 +879,7 @@ window.addEventListener('click',(e)=>{
 <p>The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.</p>
 <p>Because we destroyed the power to know who you are. So that your power can never be taken.</p>
 <p>Be free in your network.</p>
+<p><a href="https://www.youtube.com/watch?v=k-GhLNZm8G0">Watch the film</a></p>
 </div>
                 </article>
             </main>
diff --git a/docs/why.md b/docs/why.md
new file mode 100644
index 0000000000..b36df4a154
--- /dev/null
+++ b/docs/why.md
@@ -0,0 +1,21 @@
+# Why we are building SimpleX Network
+
+You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that your power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/docs/xftp-server.html b/docs/xftp-server.html
index 7649ec53f1..1462435d98 100644
--- a/docs/xftp-server.html
+++ b/docs/xftp-server.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/docs/xftp-server.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/docs/xftp-server.md b/docs/xftp-server.md
new file mode 100644
index 0000000000..4686c8a4e6
--- /dev/null
+++ b/docs/xftp-server.md
@@ -0,0 +1,650 @@
+# Hosting your own XFTP Server
+
+## Table of Contents
+
+- [Overview](#overview)
+- [Installation options](#installation-options)
+   - [systemd service](#systemd-service) with [installation script](#installation-script) or [manually](#manual-deployment)
+   - [docker container](#docker-container)
+   - [Linode marketplace](#linode-marketplace)
+- [Tor installation](#tor-installation)
+- [Configuration](#configuration)
+- [Documentation](#documentation)
+   - [XFTP server address](#xftp-server-address)
+   - [Systemd commands](#systemd-commands)
+   - [Control port](#control-port)
+   - [Daily statistics](#daily-statistics)
+- [Updating your XFTP server](#updating-your-xftp-server)
+- [Configuring the app to use the server](#configuring-the-app-to-use-the-server)
+
+## Overview
+
+XFTP is a new file transfer protocol focussed on meta-data protection - it is based on the same principles as SimpleX Messaging Protocol used in SimpleX Chat messenger:
+
+   - asynchronous file delivery - the sender does not need to be online for file to be received, it is stored on XFTP relays for a limited time (currently, it is 48 hours) or until deleted by the sender.
+   - padded e2e encryption of file content.
+   - content padding and fixed size chunks sent via different XFTP relays, assembled back into the original file by the receiving client.
+   - efficient sending to multiple recipients (the file needs to be uploaded only once).
+   - no identifiers or ciphertext in common between sent and received relay traffic, same as for messages delivered by SMP relays.
+   - protection of sender IP address from the recipients.
+
+## Installation options
+
+You can install XFTP server in one of the following ways:
+
+- [systemd service](#systemd-service)
+   - using [installation script](#installation-script) - **recommended**
+   - or [manually](#manual-deployment)
+- [Docker container](#docker-container) from DockerHub
+- [Linode marketplace](#linode-marketplace)
+
+### systemd service
+
+#### Installation script
+
+This installation script will automatically install binaries, systemd services and additional scripts that will manage backups, updates and uninstallation. This is the recommended option due to its flexibility, easy updating, and being battle tested on our servers.
+
+**Please note** that currently only Ubuntu distribution is supported.
+
+Run the following script on the server:
+
+```sh
+curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/install.sh -o simplex-server-install.sh &&\
+if echo '53fcdb4ceab324316e2c4cda7e84dbbb344f32550a65975a7895425e5a1be757 simplex-server-install.sh' | sha256sum -c; then
+  chmod +x ./simplex-server-install.sh
+  ./simplex-server-install.sh
+  rm ./simplex-server-install.sh
+else
+  echo "SHA-256 checksum is incorrect!"
+  rm ./simplex-server-install.sh
+fi
+```
+
+Type `2` and hit enter to install `xftp-server`.
+
+#### Manual deployment
+
+Manual installation is the most advanced deployment that provides the most flexibility. Generally recommended only for advanced users.
+
+1. Install binary:
+
+   - Using official binaries:
+
+     ```sh
+     curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/xftp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/xftp-server && chmod +x /usr/local/bin/xftp-server
+     ```
+
+   - Compiling from source:
+
+     Please refer to [Build from source: Using your distribution](https://github.com/simplex-chat/simplexmq#using-your-distribution)
+
+
+2. Create user and group for `xftp-server`:
+
+   ```sh
+   sudo useradd -m xftp
+   ```
+
+3. Create necessary directories and assign permissions:
+
+   ```sh
+   sudo mkdir -p /var/opt/simplex-xftp /etc/opt/simplex-xftp /srv/xftp
+   sudo chown xftp:xftp /var/opt/simplex-xftp /etc/opt/simplex-xftp /srv/xftp
+   ```
+
+4. Allow xftp-server port in firewall:
+
+   ```sh
+   # For Ubuntu
+   sudo ufw allow 443/tcp
+   # For Fedora
+   sudo firewall-cmd --permanent --add-port=443/tcp && \
+   sudo firewall-cmd --reload
+   ```
+
+5. **Optional** — If you're using distribution with `systemd`, create `/etc/systemd/system/xftp-server.service` file with the following content:
+
+   ```sh
+   [Unit]
+   Description=XFTP server systemd service
+  
+   [Service]
+   User=xftp
+   Group=xftp
+   Type=simple
+   ExecStart=/usr/local/bin/xftp-server start +RTS -N -RTS
+   ExecStopPost=/usr/bin/env sh -c '[ -e "/var/opt/simplex-xftp/file-server-store.log" ] && cp "/var/opt/simplex-xftp/file-server-store.log" "/var/opt/simplex-xftp/file-server-store.log.$(date +'%%FT%%T')"'
+   LimitNOFILE=65535
+   KillSignal=SIGINT
+   TimeoutStopSec=infinity
+   AmbientCapabilities=CAP_NET_BIND_SERVICE
+      
+   [Install]
+   WantedBy=multi-user.target
+   ```
+
+   And execute `sudo systemctl daemon-reload`.
+
+### Docker container
+
+You can deploy xftp-server using Docker Compose. This is the second recommended option due to its popularity and relatively easy deployment.
+
+This deployment provides two Docker Compose files: the **automatic** one and **manual**. If you're not sure, choose **automatic**.
+
+This will download images from [Docker Hub](https://hub.docker.com/r/simplexchat).
+
+1. Create `xftp-server` directory and switch to it:
+
+  ```sh
+  mkdir xftp-server && cd xftp-server
+  ```
+
+2. Create `docker-compose.yml` file with the following content:
+
+  You can also grab it from here - [docker-compose-xftp.yml](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-xftp.yml). Don't forget to rename it to `docker-compose.yml`.
+
+  ```yaml
+  name: SimpleX Chat - xftp-server
+
+  services:
+    xftp-server:
+      image: ${SIMPLEX_XFTP_IMAGE:-simplexchat/xftp-server:latest}
+      environment:
+        ADDR: ${ADDR?"Please specify the domain."}
+        QUOTA: ${QUOTA?"Please specify disk quota."}
+        PASS: ${PASS:-}
+      volumes:
+        - ./xftp_configs:/etc/opt/simplex-xftp
+        - ./xftp_state:/var/opt/simplex-xftp
+        - ./xftp_files:/srv/xftp
+      ports:
+        - 443:443
+      restart: unless-stopped
+  ```
+
+3. In the same directory, create `.env` file with the following content:
+
+  You can also grab it from here - [docker-compose-xftp.env](https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/stable/scripts/docker/docker-compose-xftp.yml). Don't forget to rename it to `.env`.
+
+  Change variables according to your preferences.
+
+  ```env
+  # Mandatory
+  ADDR=your_ip_or_addr
+  QUOTA=120gb
+
+  # Optional
+  #PASS='123123'
+  ```
+
+4. Start your containers:
+
+  ```sh
+  docker compose up
+  ```
+
+### Linode marketplace
+
+You can deploy xftp-server upon creating new Linode VM. Please refer to: [Linode Marketplace](https://www.linode.com/marketplace/apps/simplex-chat/simplex-chat/)
+
+## Tor installation
+
+xftp-server can also be deployed to serve from [tor](https://www.torproject.org) network. Run the following commands as `root` user.
+
+1. Install tor:
+
+   We're assuming you're using Ubuntu/Debian based distributions. If not, please refer to [official tor documentation](https://community.torproject.org/onion-services/setup/install/) or your distribution guide.
+
+   - Configure official Tor PPA repository:
+
+     ```sh
+     CODENAME="$(lsb_release -c | awk '{print $2}')"
+     echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main
+     deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org ${CODENAME} main" > /etc/apt/sources.list.d/tor.list
+     ```
+
+   - Import repository key:
+
+     ```sh
+     curl --proto '=https' --tlsv1.2 -sSf https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null
+     ```
+
+   - Update repository index:
+
+     ```sh
+     apt update
+     ```
+
+   - Install `tor` package:
+
+     ```sh
+     apt install -y tor deb.torproject.org-keyring
+     ```
+
+2. Configure tor:
+
+   - File configuration:
+  
+     Open tor configuration with your editor of choice (`nano`,`vim`,`emacs`,etc.):
+
+     ```sh
+     vim /etc/tor/torrc
+     ```
+
+     And insert the following lines to the bottom of configuration. Please note lines starting with `#`: these are comments about each individual option.
+
+     ```sh
+     # Enable log (otherwise, tor doesn't seem to deploy onion address)
+     Log notice file /var/log/tor/notices.log
+     # Enable single hop routing (2 options below are dependencies of third). Will reduce latency in exchange of anonimity (since tor runs alongside xftp-server and onion address will be displayed in clients, this is totally fine)
+     SOCKSPort 0
+     HiddenServiceNonAnonymousMode 1
+     HiddenServiceSingleHopMode 1
+     # xftp-server hidden service host directory and port mappings
+     HiddenServiceDir /var/lib/tor/simplex-xftp/
+     HiddenServicePort 443 localhost:443
+     ```
+
+   - Create directories:
+
+     ```sh
+     mkdir /var/lib/tor/simplex-xftp/ && chown debian-tor:debian-tor /var/lib/tor/simplex-xftp/ && chmod 700 /var/lib/tor/simplex-xftp/
+     ```
+
+3. Start tor:
+
+   Enable `systemd` service and start tor. Official `tor` is a bit flaky on the first start and may not create onion host address, so we're restarting it just in case.
+
+   ```sh
+   systemctl enable tor && systemctl start tor && systemctl restart tor
+   ```
+
+4. Display onion host:
+
+   Execute the following command to display your onion host address:
+
+   ```sh
+   cat /var/lib/tor/simplex-xftp/hostname
+   ```
+
+## Configuration
+
+To see which options are available, execute `xftp-server` without flags:
+
+```sh
+sudo su xftp -c xftp-server
+
+...
+Available commands:
+  init                     Initialize server - creates /etc/opt/simplex-xftp and
+                           /var/opt/simplex-xftp directories and configuration
+                           files
+  start                    Start server (configuration:
+                           /etc/opt/simplex-xftp/file-server.ini)
+  delete                   Delete configuration and log files
+
+```
+
+You can get further help by executing `su xftp -c "xftp-server <command> -h"`
+
+After that, we need to configure `xftp-server`:
+
+```sh
+sudo su xftp -c "xftp-server init -h"
+
+...
+Available options:
+  -l,--store-log           Enable store log for persistence
+  -a,--sign-algorithm ALG  Signature algorithm used for TLS certificates:
+                           ED25519, ED448 (default: ED448)
+  --ip IP                  Server IP address, used as Common Name for TLS online
+                           certificate if FQDN is not supplied
+                           (default: "127.0.0.1")
+  -n,--fqdn FQDN           Server FQDN used as Common Name for TLS online
+                           certificate
+  -p,--path PATH           Path to the directory to store files
+  -q,--quota QUOTA         File storage quota (e.g. 100gb)
+  -h,--help                Show this help text
+```
+
+You should determine which flags are needed for your use-case and then execute `xftp-server init`:
+
+```sh
+sudo su xftp -c "xftp-server init -<your flag> <your option>"
+```
+
+For example, run:
+
+```sh
+sudo su xftp -c "xftp-server init -l --ip 192.168.1.5 -q '20gb' -p /srv/xftp/"
+```
+
+to initialize your `xftp-server` configuration with:
+
+- restoring connections when the server is restarted (`-l` flag),
+- IP address `192.168.1.5` (`--ip` flag),
+- set overall storage quota to 10Gb (`-q` flag),
+- store files in `/srv/xftp` directory (`-p` flag).
+
+To password-protect your `xftp-server`, change it in the configuration:
+
+   1. Open configuration with:
+      
+      ```sh
+      sudo su xftp -c "vim /etc/opt/simplex-xftp/file-server.ini"
+      ```
+   2. Under `[AUTH]` section uncomment `create_password` and change it:
+  
+      ```sh
+      ...
+      [AUTH]
+      # Set new_files option to off to completely prohibit uploading new files.
+      # This can be useful when you want to decommission the server, but still allow downloading the existing files.
+      new_files: on
+      
+      # Use create_password option to enable basic auth to upload new files.
+      # The password should be used as part of server address in client configuration:
+      # xftp://fingerprint:password@host1,host2
+      # The password will not be shared with file recipients, you must share it only
+      # with the users who you want to allow uploading files to your server.
+      create_password: your_very_secure_password
+      ...
+      ```
+---
+
+After that, your installation is complete and you should see in your terminal output something like this:
+
+```sh
+Certificate request self-signature ok
+subject=CN = 192.168.1.5
+Server initialized, you can modify configuration in /etc/opt/simplex-xftp/file-server.ini.
+Run `file-server start` to start server.
+----------
+You should store CA private key securely and delete it from the server.
+If server TLS credential is compromised this key can be used to sign a new one, keeping the same server identity and established connections.
+CA private key location:
+/etc/opt/simplex-xftp/ca.key
+----------
+SimpleX XFTP server v0.1.0
+Fingerprint: ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=
+Server address: xftp://ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=@<hostnames>
+```
+
+The server address above should be used in your client configuration and if you added server password it should only be shared with the other people when you want to allow them to use your server to upload files. If you passed IP address or hostnames during the initialisation, they will be printed as part of server address, otherwise replace `<hostnames>` with the actual server addresses.
+
+## Documentation
+
+All necessary files for `xftp-server` are located in `/etc/opt/simplex-xftp/` folder.
+
+Stored messages, connections, statistics and server log are located in `/var/opt/simplex-xftp/` folder.
+
+Location of uploaded files is configured by the user. In our guide we're using `/srv/xftp/`
+
+### XFTP server address
+
+XFTP server address has the following format:
+
+```
+xftp://<fingerprint>[:<password>]@<public_hostname>[,<onion_hostname>]
+```
+
+- `<fingerprint>`
+
+  Your `xftp-server` fingerprint of certificate. You can check your certificate fingerprint in `/etc/opt/simplex-xftp/fingerprint`.
+
+- **optional** `<password>`
+
+  Your configured password of `xftp-server`. You can check your configured password in `/etc/opt/simplex-xftp/file-server.ini`, under `[AUTH]` section in `create_password:` field.
+
+- `<public_hostname>`, **optional** `<onion_hostname>`
+
+  Your configured hostname(s) of `xftp-server`. You can check your configured hosts in `/etc/opt/simplex-xftp/file-server.ini`, under `[TRANSPORT]` section in `host:` field.
+
+### Systemd commands
+
+To start `xftp-server` on host boot, run:
+
+```sh
+sudo systemctl enable xftp-server.service
+
+Created symlink /etc/systemd/system/multi-user.target.wants/xftp-server.service → /etc/systemd/system/xftp-server.service.
+```
+
+To start `xftp-server`, run:
+
+```sh
+sudo systemctl start xftp-server.service
+```
+
+To check status of `xftp-server`, run:
+
+```sh
+sudo systemctl status xftp-server.service
+
+● xftp-server.service - XFTP server systemd service
+     Loaded: loaded (/etc/systemd/system/xftp-server.service; enabled; vendor preset: enabled)
+     Active: active (running) since Sat 2023-03-11 13:11:55 UTC; 1 months 10 days ago
+   Main PID: 110770 (xftp-server)
+      Tasks: 14 (limit: 4611)
+     Memory: 2.4G
+     CGroup: /system.slice/xftp-server.service
+             └─110770 /usr/local/bin/xftp-server start +RTS -N -RTS
+
+Feb 27 19:21:11 localhost systemd[1]: Started XFTP server systemd service.
+Feb 27 19:21:11 localhost xftp-server[2350]: SimpleX XFTP server v0.1.0
+Feb 27 19:21:11 localhost xftp-server[2350]: Fingerprint: ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=
+Feb 27 19:21:11 localhost xftp-server[2350]: Server address: xftp://ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=@<hostnames>
+Feb 27 19:21:11 localhost xftp-server[2350]: Store log: /var/opt/simplex-xftp/file-server-store.log
+Feb 27 19:21:11 localhost xftp-server[2350]: Uploading new files allowed.
+Feb 27 19:21:11 localhost xftp-server[2350]: Listening on port 443...
+Feb 27 19:21:11 localhost xftp-server[2350]: [INFO 2023-02-27 19:21:11 +0000 src/Simplex/FileTransfer/Server/Env.hs:85] Total / available storage: 64424509440 / 64424509440
+```
+
+To stop `xftp-server`, run:
+
+```sh
+sudo systemctl stop xftp-server.service
+```
+
+To check tail of `xftp-server` log, run:
+
+```sh
+sudo journalctl -fu xftp-server.service
+
+Feb 27 19:21:11 localhost systemd[1]: Started XFTP server systemd service.
+Feb 27 19:21:11 localhost xftp-server[2350]: SimpleX XFTP server v0.1.0
+Feb 27 19:21:11 localhost xftp-server[2350]: Fingerprint: ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=
+Feb 27 19:21:11 localhost xftp-server[2350]: Server address: xftp://ioyYeRyy4SqJkNvb_7nM04MuLasOM4c-acVyVnqw248=@<hostnames>
+Feb 27 19:21:11 localhost xftp-server[2350]: Store log: /var/opt/simplex-xftp/file-server-store.log
+Feb 27 19:21:11 localhost xftp-server[2350]: Uploading new files allowed.
+Feb 27 19:21:11 localhost xftp-server[2350]: Listening on port 443...
+Feb 27 19:21:11 localhost xftp-server[2350]: [INFO 2023-02-27 19:21:11 +0000 src/Simplex/FileTransfer/Server/Env.hs:85] Total / available storage: 64424509440 / 64424509440
+```
+
+### Control port
+
+Enabling control port in the configuration allows administrator to see information about the xftp-server in real-time. Additionally, it allows to delete file chunks for content moderation and see the debug info about the clients, sockets, etc. Enabling the control port requires setting the `admin` and `user` passwords.
+
+1. Generate two passwords for each user:
+
+   ```sh
+   tr -dc A-Za-z0-9 </dev/urandom | head -c 20; echo
+   ```
+
+2. Open the configuration file:
+
+   ```sh
+   vim /etc/opt/simplex-xftp/file-server.ini
+   ```
+
+2. Configure the control port and replace the passwords:
+
+   ```ini
+   [AUTH]
+   control_port_admin_password: <your_randomly_generated_admin_password>
+   control_port_user_password: <your_randomly_generated_user_password>
+
+   [TRANSPORT]
+   control_port: 5224
+   ```
+
+3. Restart the server:
+
+   ```sh
+   systemctl restart xftp-server
+   ```
+
+To access the control port, use:
+
+```sh
+nc 127.0.0.1 5224
+```
+
+or:
+
+```sh
+telnet 127.0.0.1 5224
+```
+
+Upon connecting, the control port should print:
+
+```sh
+XFTP server control port
+'help' for supported commands
+```
+
+To authenticate, type the following and hit enter. Change the `my_generated_password` with the `user` or `admin` password from the configuration:
+
+```sh
+auth my_generated_password
+```
+
+Here's the full list of commands, their descriptions and who can access them.
+
+| Command          | Description                                                                     | Requires `admin` role      |
+| ---------------- | ------------------------------------------------------------------------------- | -------------------------- |
+| `stats-rts`      | GHC/Haskell statistics. Can be enabled with `+RTS -T -RTS` option               | -                          |
+| `delete`         | Delete known file chunk. Useful for content moderation.                         | -                          |
+| `help`           | Help menu.                                                                      | -                          |
+| `quit`           | Exit the control port.                                                          | -                          |
+
+### Daily statistics
+
+You can enable `xftp-server` statistics for `Grafana` dashboard by setting value `on` in `/etc/opt/simplex-xftp/file-server.ini`, under `[STORE_LOG]` section in `log_stats:` field.
+
+Logs will be stored as `csv` file in `/var/opt/simplex-xftp/file-server-stats.daily.log`. Fields for the `csv` file are:
+
+```sh
+fromTime,filesCreated,fileRecipients,filesUploaded,filesDeleted,dayCount,weekCount,monthCount,fileDownloads,fileDownloadAcks,filesCount,filesSize
+```
+
+- `fromTime` - timestamp; date and time of event
+
+- `filesCreated` - int; chunks created
+
+- `fileRecipients` - int; number of file chunks recipients
+
+- `filesUploaded` - int; chunks uploaded
+
+- `filesDeleted` - int; chunks deleted
+
+- `dayCount` - int; uploaded chunks in a day
+
+- `weekCount` - int; uploaded chunks in a week
+
+- `monthCount` - int; uploaded chunks in a month
+
+- `fileDownloads` - int; chunks downloaded
+
+- `filesCount` - int; count of stored file chunks
+
+- `filesSize` - int; total size of uploaded file chunks
+
+
+To import `csv` to `Grafana` one should:
+
+1. Install Grafana plugin: [Grafana - CSV datasource](https://grafana.com/grafana/plugins/marcusolsson-csv-datasource/)
+
+2. Allow local mode by appending following:
+
+   ```sh
+   [plugin.marcusolsson-csv-datasource]
+   allow_local_mode = true
+   ```
+
+   ... to `/etc/grafana/grafana.ini`
+
+3. Add a CSV data source:
+
+   - In the side menu, click the Configuration tab (cog icon)
+   - Click Add data source in the top-right corner of the Data Sources tab
+   - Enter "CSV" in the search box to find the CSV data source
+   - Click the search result that says "CSV"
+   - In URL, enter a file that points to CSV content
+
+4. You're done! You should be able to create your own dashboard with statistics.
+
+For further documentation, see: [CSV Data Source for Grafana - Documentation](https://grafana.github.io/grafana-csv-datasource/)
+
+
+## Updating your XFTP server
+
+To update your XFTP server to latest version, choose your installation method and follow the steps:
+
+   - Manual deployment
+     1. Stop the server:
+        ```sh
+        sudo systemctl stop xftp-server
+        ```
+     2. Update the binary:
+        ```sh
+         curl -L https://github.com/simplex-chat/simplexmq/releases/latest/download/xftp-server-ubuntu-20_04-x86-64 -o /usr/local/bin/xftp-server && chmod +x /usr/local/bin/xftp-server
+        ```
+     3. Start the server:
+        ```sh
+        sudo systemctl start xftp-server
+        ```
+
+   - [Official installation script](https://github.com/simplex-chat/simplexmq#using-installation-script)
+     1. Execute the following command:
+        ```sh
+        sudo simplex-servers-update
+        ```
+     2. Done!
+
+   - [Docker container](https://github.com/simplex-chat/simplexmq#using-docker)
+     1. Stop and remove the container:
+        ```sh
+        docker rm $(docker stop $(docker ps -a -q --filter ancestor=simplexchat/xftp-server --format="\{\{.ID\}\}"))
+        ```
+     2. Pull latest image:
+        ```sh
+        docker pull simplexchat/xftp-server:latest
+        ```
+     3. Start new container:
+        ```sh
+        docker run -d \
+          -p 443:443 \
+          -v $HOME/simplex/xftp/config:/etc/opt/simplex-xftp:z \
+          -v $HOME/simplex/xftp/logs:/var/opt/simplex-xftp:z \
+          -v $HOME/simplex/xftp/files:/srv/xftp:z \
+          simplexchat/xftp-server:latest
+        ```
+
+   - [Linode Marketplace](https://www.linode.com/marketplace/apps/simplex-chat/simplex-chat/)
+     1. Pull latest images:
+        ```sh
+        docker-compose --project-directory /etc/docker/compose/simplex pull
+        ```
+     2. Restart the containers:
+        ```sh
+        docker-compose --project-directory /etc/docker/compose/simplex up -d --remove-orphans
+        ```
+     3. Remove obsolete images:
+        ```sh
+        docker image prune
+        ```
+
+## Configuring the app to use the server
+
+Please see: [SMP Server: Configuring the app to use the server](https://simplex.chat/docs/server.md#configuring-the-app-to-use-the-server).
diff --git a/donate.md b/donate.md
new file mode 100644
index 0000000000..36a2d84b04
--- /dev/null
+++ b/donate.md
@@ -0,0 +1,27 @@
+# Please support us with donations
+
+Huge thank you to everybody who donated to SimpleX Chat!
+
+We are prioritizing users' privacy and security - it would be impossible without your support.
+
+Our pledge to our users is that SimpleX protocols are and will remain open, and in public domain, - so anybody can build the future implementations of the clients and the servers. We are building SimpleX platform based on the same principles as email and web, but much more private and secure.
+
+To ensure network independence and neutrality, we are currently finalizing the launch of [SimpleX Network Consortium](https://simplexnetwork.org/) - an agreement between SimpleX Network Foundation that is being formed as 501.c3 non-profit and SimpleX Chat company.
+
+Your donations help us raise more funds - any amount, even the price of the cup of coffee, makes a big difference for us.
+
+Please donate via:
+
+- [GitHub](https://github.com/sponsors/simplex-chat) (commission-free) or [OpenCollective](https://opencollective.com/simplex-chat) (~10% commission)
+- BTC: [bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u](bitcoin:bc1q2gy6f02nn6vvcxs0pnu29tpnpyz0qf66505d4u)
+- XMR: [8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c](monero:8A3ZWAXrrQddvnT1fPrtbK86ZAoM4nai3Gjg1LEow3JWcryJtovMnHYZnxTJpCLmAbfWbnPMeTzPmMBjAhyd4xoM89hYq1c)
+- ETH/USDT (Ethereum, Arbitrum One): [0xD7047Fe3Eecb2f2FF78d839dD927Be27Bc12c86a](ethereum:0xD7047Fe3Eecb2f2FF78d839dD927Be27Bc12c86a) ([donate.simplexchat.eth](ethereum:0xD7047Fe3Eecb2f2FF78d839dD927Be27Bc12c86a))
+- [Other cryptocurrencies](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Thank you,
+
+Evgeny, SimpleX Chat founder
+
+## SimpleX Community Credits
+
+Please comment on our plan to make SimpleX network sustainable: https://simplex.chat/credits
diff --git a/donate/index.html b/donate/index.html
index bc82206c9c..ff5cec01c4 100644
--- a/donate/index.html
+++ b/donate/index.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/donate.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/downloads.md b/downloads.md
new file mode 100644
index 0000000000..eff6f1266a
--- /dev/null
+++ b/downloads.md
@@ -0,0 +1,44 @@
+# Download SimpleX apps
+
+You can get the latest beta releases from [GitHub](https://github.com/simplex-chat/simplex-chat/releases).
+
+If you cannot access GitHub, you can download SimpleX Chat apps from our mirror at [git.simplex.chat](https://git.simplex.chat/simplex-chat/simplex-chat/releases)
+
+- [desktop](#desktop-app)
+- [mobile](#mobile-apps)
+- [terminal](#terminal-console-app) (console)
+
+## Desktop app
+
+<img src="/docs/images/simplex-desktop-light.png" alt="desktop app" width=500>
+
+You can link your mobile device with desktop to use the same profile remotely, but this is only possible when both devices are connected to the same local network.
+
+**Linux**:
+- Most Linux distros: AppImage ([x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-x86_64.AppImage), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-aarch64.AppImage)) or [Flatpak](https://flathub.org/apps/chat.simplex.simplex).
+- Ubuntu 22.04 and Debian-based distros ([x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-ubuntu-22_04-x86_64.deb), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-ubuntu-22_04-aarch64.deb)).
+- Ubuntu 24.04 ([x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-ubuntu-24_04-x86_64.deb), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-ubuntu-24_04-aarch64.deb)).
+
+You can [verify and reproduce](https://simplex.chat/reproduce/index.html) Linux builds.
+
+**Mac**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-macos-x86_64.dmg) (Intel), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-macos-aarch64.dmg) (Apple Silicon).
+
+**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-desktop-windows-x86_64.msi).
+
+## Mobile apps
+
+**iOS**: [App store](https://apps.apple.com/us/app/simplex-chat/id1605771084), [TestFlight](https://testflight.apple.com/join/DWuT2LQu).
+
+**Android**: [Play store](https://play.google.com/store/apps/details?id=chat.simplex.app), [F-Droid](https://simplex.chat/fdroid/), [APK aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk), [APK armv7](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-armv7a.apk).
+
+You can [verify and reproduce](https://simplex.chat/reproduce/index.html) Android APKs.
+
+## Terminal (console) app
+
+See [Using terminal app](https://simplex.chat/docs/cli.md).
+
+**Linux**: Ubuntu 22.04 ([x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-ubuntu-22_04-x86_64), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-ubuntu-22_04-aarch64)), Ubuntu 24.04 ([x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-ubuntu-24_04-x86_64), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-ubuntu-24_04-aarch64)).
+
+**Mac**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-macos-x86-64), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-macos-aarch64).
+
+**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-chat-windows-x86-64).
diff --git a/downloads/index.html b/downloads/index.html
index b7c3f11ed3..ebe6b59133 100644
--- a/downloads/index.html
+++ b/downloads/index.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/downloads.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/en/contact.md b/en/contact.md
new file mode 100644
index 0000000000..ecf1706558
--- /dev/null
+++ b/en/contact.md
@@ -0,0 +1,66 @@
+# You received an address to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received an address to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
diff --git a/en/contact/index.html b/en/contact/index.html
index c560415fa3..19a62bd805 100644
--- a/en/contact/index.html
+++ b/en/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received an address to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
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@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
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@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
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@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
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-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/en/fdroid.md b/en/fdroid.md
new file mode 100644
index 0000000000..296adf884e
--- /dev/null
+++ b/en/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stable and beta versions built by the developers
+
+To add it to your F-Droid client, scan the QR code or use this URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stable versions built by F-Droid.org
+
+The releases to this repo are done several days later.
+
+SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please [export](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) the chat database and re-install the app.
diff --git a/en/fdroid/index.html b/en/fdroid/index.html
index f729814b0d..2109809ce6 100644
--- a/en/fdroid/index.html
+++ b/en/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
                         <p>To add it to your F-Droid client, <span class="hide-on-mobile">scan the QR code or</span> use this URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stable versions built by F-Droid.org</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
                 <p class="mb-2">SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">export</a> the chat database and re-install the app.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/en/file.md b/en/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/en/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/en/file/index.html b/en/file/index.html
index 2a823bae39..9477ce2a4f 100644
--- a/en/file/index.html
+++ b/en/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/en/index.html b/en/index.html
index a679925d1e..2b4701d75e 100644
--- a/en/index.html
+++ b/en/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/en/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/en/index.md b/en/index.md
new file mode 100644
index 0000000000..43aea883b3
--- /dev/null
+++ b/en/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Learn more.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/why)
+
+## Funded by Its Users
+
+To stay independent, large channels and communities will pay for their servers.
+
+And the users can now invest in SimpleX Chat — the equity crowdfunding is live!
+
+[Get a stake in SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/en/invitation.md b/en/invitation.md
new file mode 100644
index 0000000000..fd84b8ba88
--- /dev/null
+++ b/en/invitation.md
@@ -0,0 +1,66 @@
+# You received a 1-time link to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received a 1-time link to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
diff --git a/en/invitation/index.html b/en/invitation/index.html
index c3bc77749f..21967f044d 100644
--- a/en/invitation/index.html
+++ b/en/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received a 1-time link to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/en/messaging.md b/en/messaging.md
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--- /dev/null
+++ b/en/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Why SimpleX is unique
+
+### You have complete privacy
+
+SimpleX protects the privacy of your profile, contacts and metadata, hiding it from SimpleX network servers and any observers.
+
+Unlike any other existing messaging network, SimpleX has no identifiers assigned to the users — **not even random numbers**.
+
+### You are protected from spam and abuse
+
+Because you have no identifier or fixed address on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+### You control your data
+
+SimpleX stores all user data on client devices in a **portable encrypted database format** — it can be transferred to another device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+### You own SimpleX network
+
+The SimpleX network is fully decentralised and independent of any crypto-currency or any other network, other than the Internet.
+
+You can **use SimpleX with your own servers** or with the servers provided by us — and still connect to any user.
+
+# Full privacy of your identity, profile, contacts and metadata
+
+Unlike other messaging networks, SimpleX has **no identifiers assigned to the users**. It does not rely on phone numbers, domain-based addresses (like email or XMPP), usernames, public keys or even random numbers to identify its users — SimpleX server operators don't know how many people use their servers.
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# The best protection from spam and abuse
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# Ownership, control and security of your data
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+There are no identifiers or ciphertext in common between sent and received server traffic — if anybody is observing it, they cannot easily determine who communicates with whom, even if TLS is compromised.
+
+# Fully decentralised — users own the SimpleX network
+
+You can **use SimpleX with your own servers** and still communicate with people who use the servers preconfigured in the apps.
+
+SimpleX network uses an [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) and provides [SDK to create chat bots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), allowing implementation of services that users can interact with via SimpleX Chat apps — we're really looking forward to seeing what SimpleX services you will build.
+
+If you are considering developing for the SimpleX network, for example, the chat bot for SimpleX app users, or the integration of the SimpleX Chat library into your mobile apps, please [get in touch](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) for any advice and support.
+
+## Features
+
+E2E-encrypted messages with markdown and editing
+
+E2E-encrypted
+images, videos and files
+
+E2E-encrypted decentralized groups — only users know they exist
+
+E2E-encrypted voice messages
+
+Disappearing messages
+
+E2E-encrypted
+audio and video calls
+
+Portable encrypted app storage — move profile to another device
+
+Incognito mode —
+unique to SimpleX Chat
+
+## What makes SimpleX private
+
+### Temporary anonymous pairwise identifiers
+
+SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member.
+
+It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.
+
+### Out-of-band key exchange
+
+Many communication networks are vulnerable to MITM attacks by servers or network providers.
+
+To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.
+
+### 2-layers of end-to-end encryption
+
+Double-ratchet protocol —
+OTR messaging with perfect forward secrecy and break-in recovery.
+
+NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.
+
+### Message integrity verification
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### Additional layer of server encryption
+
+Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.
+
+### Message mixing to reduce correlation
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### Secure authenticated TLS transport
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+Connection resumption is disabled to prevent session attacks.
+
+### Optional access via Tor
+
+To protect your IP address you can access the servers via Tor or some other transport overlay network.
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Unidirectional message queues
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+It reduces the attack vectors, compared with traditional message brokers, and available meta-data.
+
+### Multiple layers of content padding
+
+SimpleX uses content padding for each encryption layer to frustrate message size attacks.
+
+It makes messages of different sizes look the same to the servers and network observers.
+
+## SimpleX Network
+
+SimpleX Chat provides the best privacy by combining the advantages of P2P and federated networks.
+
+### Unlike P2P networks
+
+All messages are sent via the servers, both providing better metadata privacy and reliable asynchronous message delivery, while avoiding many .
+
+# Comparison with P2P messaging protocols
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messaging protocols and apps have various problems that make them less reliable than SimpleX, more complex to analyse, and vulnerable to several types of attack.
+
+1. P2P networks rely on some variant of [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) to route messages. DHT designs have to balance delivery guarantee and latency. SimpleX has both better delivery guarantee and lower latency than P2P, because the message can be redundantly passed via several servers in parallel, using the servers chosen by the recipient. In P2P networks the message is passed through *O(log N)* nodes sequentially, using nodes chosen by the algorithm.
+2. SimpleX design, unlike most P2P networks, has no global user identifiers of any kind, even temporary, and only uses temporary pairwise identifiers, providing better anonymity and metadata protection.
+3. P2P does not solve [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problem, and most existing implementations do not use out-of-band messages for the initial key exchange. SimpleX uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### Unlike federated networks
+
+SimpleX relay servers do NOT store user profiles, contacts and delivered messages, do NOT connect to each other, and there is NO servers directory.
+
+---
+
+### SimpleX network
+
+servers provide unidirectional queues to connect the users, but they have no visibility of the network connection graph — only the users do.
+
+## SimpleX explained
+
+1. What users experience
+
+2. How does it work
+
+3. What servers see
+
+1. What users experience
+
+You can create contacts and groups, and have two-way conversations, as in any other messenger.
+
+How can it work with unidirectional queues and without user profile identifiers?
+
+2. How does it work
+
+For each connection you use two separate messaging queues to send and receive messages via different servers.
+
+Servers only pass messages one way, without having the full picture of user's conversations or connections.
+
+3. What servers see
+
+The servers have separate anonymous credentials for each queue, and do not know which users they belong to.
+
+Users can further improve metadata privacy by using Tor to access servers, preventing correlation by IP address.
+
+## Comparison with other protocols
+
+|  |  | Signal, big platforms | XMPP, Matrix | P2P protocols |
+| --- | --- | --- | --- | --- |
+| Requires global identity | No - private | Yes [1] | Yes [2] | Yes [3] |
+| Possibility of MITM | No - secure [4] | Yes [5] | Yes | Yes |
+| Dependence on DNS | No - resilient | Yes | Yes | No |
+| Single or centralized network | No - decentralized | Yes | No - federated [6] | Yes [7] |
+| Central component or other network-wide attack | No - resilient | Yes | Yes [2] | Yes [8] |
+
+---
+
+1. Usually based on a phone number, in some cases on usernames
+2. DNS-based addresses
+3. Public key or some other globally unique ID
+4. SimpleX relays cannot compromise e2e encryption. Verify security code to mitigate attack on out-of-band channel
+5. If operator's servers are compromised. Verify security code in Signal and some other apps to mitigate it
+6. Does not protect users' metadata privacy
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. P2P networks either have a central authority or the whole network can be compromised — [see here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [see here](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/en/messaging/index.html b/en/messaging/index.html
index 9b1182cf9e..9d8d2ed42c 100644
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connection resumption is disabled to prevent session attacks.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It reduces the attack vectors, compared with traditional message brokers, and available meta-data.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It makes messages of different sizes look the same to the servers and network observers.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
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         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
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 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/en/why.md b/en/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/en/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/en/why/index.html b/en/why/index.html
index d07088c007..330576099c 100644
--- a/en/why/index.html
+++ b/en/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/en/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/es/contact.md b/es/contact.md
new file mode 100644
index 0000000000..0d1ec535a4
--- /dev/null
+++ b/es/contact.md
@@ -0,0 +1,66 @@
+# Has recibido una dirección para conectarte con SimpleX Chat
+
+## Escanéa el código QR en tu teléfono o tableta con la aplicación SimpleX Chat.
+
+Las claves públicas y la dirección de la cola de mensajes de este enlace NO se envían a través de la red cuando ves esta página. Están contenidos en el fragmento hash del URL del enlace.
+
+¿Aún no has descargado SimpleX Chat?
+
+Usa los siguientes enlaces para descargar la aplicación.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Escanear el código QR desde la aplicación móvil
+
+# Has recibido una dirección para conectarte con SimpleX Chat
+
+Para establecer una conexión:
+
+Instalar SimpleX Chat
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid)
+
+1
+
+Conectar en la aplicación
+
+Abrir la app SimpleX
+
+2
+
+Pulsa el botón "conectar" en la aplicación
+
+3
+
+## Escanear el código QR con la aplicación SimpleX Chat
+
+Las claves públicas y la dirección de la cola de mensajes de este enlace NO se envían a través de la red cuando ves esta página.
+Están contenidos en el fragmento hash del URL del enlace.
+
+## Instalación de chat SimpleX en el terminal
+
+Usa este comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Ver SimpleX Chat Repositorio GitHub instrucciones para descargar o compilar desde el código fuente.
+
+---
+
+## Si ya has instalado SimpleX Chat para el terminal
+
+Si ya has instalado SimpleX Chat para el terminal v1.0.0+, copia el siguiente comando y úsalo en el chat:
+
+## Únete a SimpleX
+
+Te invitamos a unirte a la conversación
+
+[Únete a la comunidad REDDIT](https://www.reddit.com/r/SimpleXChat/) [Únete a nosotros en GitHub](https://github.com/simplex-chat) [Dona aquí para ayudarnos](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Suscríbete para recibir actualizaciones
+
+---
+
+Obtén SimpleX [para desktop](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid)
diff --git a/es/contact/index.html b/es/contact/index.html
index 975981d265..62851f6006 100644
--- a/es/contact/index.html
+++ b/es/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Has recibido una dirección para conectarte con SimpleX Chat</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Usa los siguientes enlaces para descargar la aplicación.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instalar SimpleX Chat</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Escanear el código QR con la aplicación SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalación de chat SimpleX en el terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositorio GitHub</span>
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                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Si ya has instalado SimpleX Chat para el terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Suscríbete para recibir actualizaciones</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Escribe tu correo electrónico">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtén SimpleX <a href="/downloads">para desktop</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/fdroid.md b/es/fdroid.md
new file mode 100644
index 0000000000..b02c9bcefe
--- /dev/null
+++ b/es/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat en F-Droid
+
+### Repositorio SimpleX Chat
+
+Versiones estables y beta compilados por los desarrolladores
+
+Para añadirlo al cliente F-Droid, escanea el código QR o usa esta URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Huella de la clave (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Repositorio F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Versión estable compilada por F-Droid.org
+
+Las versiones se publican varios días más tarde en este repositorio.
+
+Los repositorios de SimpleX Chat y F-Droid.org firman con claves distintas. Para pasar de uno a otro, por favor [exporta](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) la base de datos y reinstala la aplicación.
diff --git a/es/fdroid/index.html b/es/fdroid/index.html
index 97da2c086a..7ac2bccb80 100644
--- a/es/fdroid/index.html
+++ b/es/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat en F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Versiones estables y beta compilados por los desarrolladores</p>
                         <p>Para añadirlo al cliente F-Droid, <span class="hide-on-mobile">escanea el código QR o</span> usa esta URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Huella de la clave (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Repositorio F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Versión estable compilada por F-Droid.org</p>
                 <p class="mb-2">Las versiones se publican varios días más tarde en este repositorio.</p>
                 <p class="mb-2">Los repositorios de SimpleX Chat y F-Droid.org firman con claves distintas. Para pasar de uno a otro, por favor <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exporta</a> la base de datos y reinstala la aplicación.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/file.md b/es/file.md
new file mode 100644
index 0000000000..21fd239c72
--- /dev/null
+++ b/es/file.md
@@ -0,0 +1,31 @@
+# Transferencia de archivos SimpleX
+
+Arrastra y suelta el archivo aquí
+
+o
+
+Seleccionar archivo
+
+Max 100 MB - [La app SimpleX Chat](https://simplex.chat/downloads) soporta archivos hasta 1GB
+
+Envía archivos cifrados de extremo a extremo de forma segura - sin cuentas, sin ser monitorizado.
+
+## Descarga SimpleX Chat — el mensajero privado & más seguro
+
+La transferencia de archivos que acabas de usar emplea el mismo protocolo de enrutamiento de datos que SimpleX Chat. La aplicación ofrece mensajería, llamadas de voz y video, grupos y envío de archivos con cifrado de extremo a extremo. Sin cuentas. Sin teléfono. Sin correo electrónico. Sin identificadores de usuario.
+
+# Protocolo XFTP, la transferencia de archivos más segura
+
+### No se necesita cuenta
+
+Cada fragmento del archivo usa una clave aleatoria. Los routers de datos no tienen "usuarios" o "archivos", solo transportan los fragmentos cifrados con un tamaño fijo.
+
+### Triple cifrado en tu navegador
+
+La clave de cifrado está presente solo en el fragmento hash de la URL, tu navegador nunca lo envía a un servidor. Hay tres capas de cifrado: transporte TLS, clave por transferencia (clave única y temporal por cada transferencia), y cifrado de extremo a extremo del archivo.
+
+### Routers de datos independientes
+
+Cuando un archivo se divide en fragmentos, se envía a través de routers en la red gestionados por terceros independientes. Ningún operador puede ver el nombre o el tamaño real del archivo. Incluso si un enrutador se ve comprometido, solo puede ver fragmentos cifrados de tamaño fijo. Los fragmentos de los archivos se almacenan por los routers de la red durante aproximadamente 48 horas.
+
+[Sobre las especificaciones del protocolo XFTP →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/es/file/index.html b/es/file/index.html
index 45d5788874..08e93168d4 100644
--- a/es/file/index.html
+++ b/es/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">Transferencia de archivos SimpleX</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Arrastra y suelta el archivo aquí</p>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Descarga SimpleX Chat — el mensajero privado &amp; más seguro
+      Descarga SimpleX Chat &mdash; el mensajero privado &amp; más seguro
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       La transferencia de archivos que acabas de usar emplea el mismo protocolo de enrutamiento de datos que SimpleX Chat. La aplicación ofrece mensajería, llamadas de voz y video, grupos y envío de archivos con cifrado de extremo a extremo. Sin cuentas. Sin teléfono. Sin correo electrónico. Sin identificadores de usuario.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/es/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/es/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/index.html b/es/index.html
index 485eefe0e9..a2a7173ca6 100644
--- a/es/index.html
+++ b/es/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/es/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/es/fdroid" title="SimpleX app vía F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Betas SimpleX para iOS en TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Betas SimpleX para iOS en TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Auditorías de seguridad" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Ahora</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/es/index.md b/es/index.md
new file mode 100644
index 0000000000..bce605c7b7
--- /dev/null
+++ b/es/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Sé Libre
+
+## En Tu Red
+
+La primera red sin IDs de usuario.
+Tus contactos, grupos y canales te pertenecen.
+
+Invierte en SimpleX Chat. [Descubre más.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app vía F-Droid](https://simplex.chat/es/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Auditorías de seguridad](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Auditorías
+en Seguridad
+
+[Recomendaciones de mensajería de Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Recomendación de mensajería de Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publicaciones Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Revisión por Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Entrevista en podcast de OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nadie Puede Ver Con Quién Hablas
+
+Ni siquiera los servidores – todos los mensajes parecen ruido aleatorio.
+
+Decenas de millones de mensajes entregados de forma privada cada día.
+
+[Descubre más sobre la mensajería SimpleX](https://simplex.chat/es/messaging)
+
+## La Red Te Pertenece
+
+Cada contacto y grupo está en tu dispositivo, no en la base de datos de un servidor.
+
+Ninguna entidad controla la red – cualquiera puede ejecutar servidores.
+
+[Por qué la estamos creando](https://simplex.chat/es/why)
+
+## Financiada por Sus Usuarios
+
+Para mantenerse independientes, los canales y comunidades grandes pagarán por sus servidores.
+
+Y los usuarios ya pueden invertir en SimpleX Chat — ¡el crowdfunding está activo!
+
+[Invertir en SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Ruta SimpleX hacía el Internet Libre
+
+2026
+
+: Escalar a Comunidades Grandes
+
+Huir de plataformas centralizadas
+
+Jun 2027
+
+: Comunidades y Servidores Sostenibles
+
+Lanzamiento de Créditos Comunitarios
+
+Dic 2027
+
+: Haz Crecer Tus Comunidades
+
+Herramientas para la promoción
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Únete a las Comunidades SimpleX
+
+Más de 2 millones de personas descargaron las aplicaciones SimpleX.
+
+¡Encuentra tus canales y comunidades en el directorio y crea los tuyos!
+
+[Ir al Directorio SimpleX](https://simplex.chat/directory)
diff --git a/es/invitation.md b/es/invitation.md
new file mode 100644
index 0000000000..2e15106b8a
--- /dev/null
+++ b/es/invitation.md
@@ -0,0 +1,66 @@
+# Has recibido un enlace de un solo uso para conectarte con SimpleX Chat
+
+## Escanéa el código QR en tu teléfono o tableta con la aplicación SimpleX Chat.
+
+Las claves públicas y la dirección de la cola de mensajes de este enlace NO se envían a través de la red cuando ves esta página. Están contenidos en el fragmento hash del URL del enlace.
+
+¿Aún no has descargado SimpleX Chat?
+
+Usa los siguientes enlaces para descargar la aplicación.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Escanear el código QR desde la aplicación móvil
+
+# Has recibido un enlace de un solo uso para conectarte con SimpleX Chat
+
+Para establecer una conexión:
+
+Instalar SimpleX Chat
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid)
+
+1
+
+Conectar en la aplicación
+
+Abrir la app SimpleX
+
+2
+
+Pulsa el botón "conectar" en la aplicación
+
+3
+
+## Escanear el código QR con la aplicación SimpleX Chat
+
+Las claves públicas y la dirección de la cola de mensajes de este enlace NO se envían a través de la red cuando ves esta página.
+Están contenidos en el fragmento hash del URL del enlace.
+
+## Instalación de chat SimpleX en el terminal
+
+Usa este comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Ver SimpleX Chat Repositorio GitHub instrucciones para descargar o compilar desde el código fuente.
+
+---
+
+## Si ya has instalado SimpleX Chat para el terminal
+
+Si ya has instalado SimpleX Chat para el terminal v1.0.0+, copia el siguiente comando y úsalo en el chat:
+
+## Únete a SimpleX
+
+Te invitamos a unirte a la conversación
+
+[Únete a la comunidad REDDIT](https://www.reddit.com/r/SimpleXChat/) [Únete a nosotros en GitHub](https://github.com/simplex-chat) [Dona aquí para ayudarnos](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Suscríbete para recibir actualizaciones
+
+---
+
+Obtén SimpleX [para desktop](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/es/fdroid)
diff --git a/es/invitation/index.html b/es/invitation/index.html
index d6579808ad..28bf4f6176 100644
--- a/es/invitation/index.html
+++ b/es/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Has recibido un enlace de un solo uso para conectarte con SimpleX Chat</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Usa los siguientes enlaces para descargar la aplicación.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instalar SimpleX Chat</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Escanear el código QR con la aplicación SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalación de chat SimpleX en el terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositorio GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
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+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Si ya has instalado SimpleX Chat para el terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Suscríbete para recibir actualizaciones</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Escribe tu correo electrónico">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtén SimpleX <a href="/downloads">para desktop</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/es/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/es/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/messaging.md b/es/messaging.md
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--- /dev/null
+++ b/es/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Por qué SimpleX es único
+
+### La privacidad es completa
+
+SimpleX protege la privacidad de tu perfil, contactos y metadatos, ocultándolos de los servidores SimpleX y de cualquier observador.
+
+A diferencia de cualquier otra red de mensajería existente, SimpleX no tiene identificadores asignados a los usuarios, **ni siquiera números aleatorios**.
+
+### Estás protegido contra el spam y el abuso
+
+Al no tener identificadores o dirección permanente en la red SimpleX, nadie puede ponerse en contacto contigo salvo que compartas una dirección de usuario de un solo uso o una dirección temporal en forma de enlace o código QR.
+
+### Tu gestionas tus datos
+
+SimpleX almacena todos los datos de usuario únicamente en los dispositivos cliente usando un **formato cifrado y portable de la base de datos**, la cual puede ser transferida a otro dispositivo.
+
+Los mensajes cifrados de extremo a extremo (E2E) se mantienen temporalmente en los servidores SimpleX hasta que se entregan al destinatario, y después se borran definitivamente.
+
+### La red SimpleX te pertenece
+
+La red SimpleX está completamente descentralizada y es independiente de cualquier criptodivisa o de cualquier red salvo Internet.
+
+Puedes **usar SimpleX con tus propios servidores** o con los servidores proporcionados por nosotros para contactar con cualquier usuario.
+
+# Privacidad total de tu identidad, perfil, contactos y metadatos
+
+A diferencia de otras redes de mensajería, SimpleX **no tiene identificadores asignados a los usuarios**. No depende de números de teléfono, direcciones basadas en dominios (como es el caso del email o XMPP), nombres de usuario, claves públicas o incluso números aleatorios para identificar a sus usuarios. Los operadores de servidores SimpleX desconocen cuántas personas usan sus servidores.
+
+Para la entrega de mensajes, SimpleX usa [direcciones anónimas por pares](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) de colas de mensajes unidireccionales separadas para mensajes salientes y entrantes a través de servidores diferentes.
+
+Este diseño protege la privacidad de la persona que se comunica contigo ocultándole a los servidores de la red SimpleX y de cualquier observador. Para ocultar tu dirección IP a los servidores puedes **conectarte a los servidores SimpleX mediante Tor**.
+
+# La mejor protección contra el spam y el abuso
+
+Al no tener identificadores en la red SimpleX, nadie puede ponerse en contacto contigo salvo que compartas una dirección de usuario de un solo uso o una dirección temporal en forma de enlace o código QR.
+
+Incluso con la dirección de usuario opcional, aunque pueda usarse para enviar solicitudes de contacto spam, puedes cambiarla o eliminarla por completo sin perder ninguna de tus conexiones.
+
+# Titularidad, control y seguridad de tus datos
+
+SimpleX Chat almacena todos los datos de usuario únicamente en los dispositivos cliente usando un **formato cifrado y portable de la base de datos**, la cual puede ser exportada y transferida a cualquier dispositivo compatible.
+
+Los mensajes cifrados de extremo a extremo (E2E) se mantienen temporalmente en los servidores SimpleX hasta que se entregan al destinatario, y después se borran definitivamente.
+
+A diferencia de los servidores de redes federadas (correo electrónico, XMPP o Matrix), los servidores SimpleX no almacenan cuentas de usuario, sólo retransmiten mensajes, protegiendo así la privacidad de ambas partes.
+
+No hay identificadores ni texto cifrado en común entre el tráfico de servidor enviado y el recibido. Si alguien te está monitorizando, difícilmente podría determinar quién se comunica con quién, incluso si el protocolo TLS se ve comprometido.
+
+# Totalmente descentralizado, los usuarios son dueños de la red SimpleX
+
+Puedes **usar SimpleX con tus propios servidores** y aún así comunicarte con personas que usen los servidores preconfigurados de la aplicación.
+
+La red SimpleX usa un [protocolo abierto](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) y proporciona el [SDK para crear chatbots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), permitiendo implementar servicios con los que los usuarios interactúen con las aplicaciones SimpleX Chat — esperamos ver con interés los servicios SimpleX que creará usted.
+
+Si estás considerando desarrollar para la red SimpleX, por ejemplo un chatbot para los usuarios de SimpleX o la integración de las librerías SimpleX Chat en tus aplicaciones móviles, por favor [ponte en contacto](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) para consejos y soporte.
+
+## Características
+
+Mensajes cifrados E2E
+con sintáxis markdown y edición
+
+Cifrado E2E
+de imágenes, vídeos y archivos
+
+Grupos descentralizados cifrados E2E, sólo los usuarios saben de su existencia
+
+Mensajes de voz cifrados E2E
+
+Mensajes temporales
+
+Llamadas y videollamadas
+con cifrado E2E
+
+Almacenamiento portable y cifrado, podrás transferir tu perfil a otro dispositivo
+
+Modo Incógnito
+exclusivo de SimpleX Chat
+
+## Qué hace que SimpleX sea privado
+
+### Identificadores por pares temporales y anónimos
+
+SimpleX usa direcciones y credenciales temporales y anónimas por pares para cada contacto o miembro del grupo.
+
+Permite la entrega de mensajes sin identificadores del perfil de usuario y proporciona mayor privacidad de metadatos que las alternativas.
+
+### Intercambio de claves fuera de banda
+
+Muchas redes de comunicaciónes son vulnerables a ataques MITM por parte de los servidores o los proveedores de red.
+
+Para evitarlo las aplicaciones SimpleX pasan claves de un solo uso fuera de banda cuando compartes un enlace de dirección o un código QR.
+
+### Doble capa de cifrado de extremo a extremo
+
+Protocolo de '[Double Ratchet](https://en.wikipedia.org/wiki/Double_Ratchet_Algorithm)' —
+Mensajería [OTR](https://es.wikipedia.org/wiki/Off_the_record_messaging) con [secreto perfecto hacia adelante](https://es.wikipedia.org/wiki/Perfect_forward_secrecy) y recuperación de intrusión.
+
+Y si el protocolo TLS se ve comprometido, NaCL cryptobox en cada cola de mensajes para prevenir la correlación de tráfico entre las colas.
+
+### Verificación de la integridad del mensaje
+
+Para garantizar la integridad los mensajes se numeran secuencialmente e incluyen el hash del mensaje anterior.
+
+Si se añade, elimina o modifica algún mensaje, el destinatario es avisado.
+
+### Capa de cifrado adicional en el servidor
+
+Capa de cifrado adicional desde el servidor al destinatario, para prevenir la correlación entre el tráficos de entrada y salida del servidor si el protocolo TLS se ve comprometido.
+
+### Mezcla de mensajes para prevenir la correlación
+
+Los servidores SimpleX actúan como nodos de mezcla de baja latencia, los mensajes entrantes y salientes siguen un orden diferente.
+
+### Transporte TLS seguro y autenticado
+
+Para las conexiones cliente servidor se usan exclusivamente el protocolo TLS 1.2/1.3 con algoritmos robustos.
+
+La huella digital del servidor y la vinculación de canales evitan los ataques de respuesta y MITM.
+
+La reanudación de la conexión está deshabilitada para evitar ataques de sesión.
+
+### Acceso opcional a través de Tor
+
+Para proteger tu dirección IP, puedes acceder a los servidores a través Tor u otra red superpuesta de transporte.
+
+Para usar SimpleX a través de Tor, instala la aplicación [Orbot](https://guardianproject.info/apps/org.torproject.android/) y activa el proxy SOCKS5 (o VPN [en iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Colas de mensajes unidireccionales
+
+Cada cola de mensajes transmite los mensajes en un sol sentido. entre las direcciónes de envío y recepción.
+
+Esto reduce los vectores de ataque y los metadatos disponibles en comparación con los brokers de mensajes tradicionales.
+
+### Múltiples capas de contenido acolchado
+
+SimpleX utiliza relleno de contenido en cada capa de cifrado para frustrar los ataques al tamaño de los mensajes.
+
+Esto hace que mensajes de distintos tamaños parezcan iguales desde el punto de vista de servidores y observadores de red.
+
+## Red SimpleX
+
+SimpleX Chat proporciona la mejor privacidad al combinar las ventajas de P2P y las redes federadas.
+
+### Distinta de las redes P2P
+
+Todos los mensajes se envían a través de los servidores, proporcionando mejor privacidad para los metadatos y entrega asíncrona fiable, evitando al mismo tiempo muchos de los .
+
+# Comparativa con protocolos de mensajería P2P
+
+Los protocolos y aplicaciones de mensajería [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) presentan varios problemas que los hacen menos fiables que SimpleX, más complejos de analizar y más vulnerables a ciertos tipos de ataques.
+
+1. Para enrutar mensajes, las redes P2P se basan en alguna variante de [DHT](https://es.wikipedia.org/wiki/Tabla_de_hash_distribuida). Los diseños DHT tienen que equilibrar la garantía de entrega y latencia. SimpleX ofrece mayor garantía de entrega y menor latencia que P2P ya que el mensaje puede transmitirse en paralelo y de forma redundante a través de varios servidores elegidos por el destinatario. En las redes P2P el mensaje se transmite secuencialmente por *O(log N)* nodos, usando nodos elegidos por el algoritmo.
+2. Por diseño SimpleX, a diferencia de la mayoría de las redes P2P, no tiene identificadores globales de usuario de ningún tipo, ni siquiera temporales, y sólo usa identificadores temporales por pares, lo que proporciona un mejor anonimato y protección de los metadatos.
+3. P2P no resuelve el problema del [ataque MITM](https://es.wikipedia.org/wiki/Ataque_de_intermediario) , y la mayoría de implementaciones existentes no usan mensajes fuera de banda para el intercambio de claves inicial. SimpleX usa mensajes fuera de banda, o en algunos casos conexiones seguras y de confianza preexistentes para el intercambio inicial de claves.
+4. Algunos proveedores de Internet pueden bloquear las aplicaciones P2P (como [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX es independiente del transporte. Puede trabajar con protocolos web estándar, por ejemplo WebSockets.
+5. Todas las redes P2P conocidas pueden ser vulnerables al ataque [Sybil](https://es.wikipedia.org/wiki/Ataque_Sybil) porque cada nodo es susceptible de ser descubierto y la red funciona como una unidad. Las medidas de mitigación conocidas requieren un componente centralizado o bien costosas [pruebas de trabajo](https://en.wikipedia.org/wiki/Proof_of_work). La red SimpleX no tiene la capacidad para descubrir los servidores, está fragmentada y funciona como múltiples subredes aisladas haciendo imposibles los ataques a toda la red.
+6. Las redes P2P pueden ser vulnerables al [ataque DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), en el que los clientes retransmiten y amplifican el tráfico provocando el bloqueo del servicio en la red. Los clientes SimpleX sólo transmiten el tráfico desde conexiones conocidas y no pueden ser usados por un atacante para amplificar el tráfico en toda la red.
+
+---
+
+### Distinta de las redes federadas
+
+Los servidores de SimpleX NO almacenan perfiles de usuario, contactos, o mensajes entregados. NO contactan entre sí y NO existe un directorio de servidores.
+
+---
+
+### Red Simplex
+
+los servidores proporcionan colas unidireccionales para conectar a los usuarios pero no ven la gráfica de conexiónes red, sólo los usuarios pueden verla.
+
+## SimpleX explicado
+
+1. Experiencia del usuario
+
+2. Cómo funciona la red
+
+3. Qué ven los servidores
+
+1. Experiencia del usuario
+
+Puedes crear contactos y grupos, y mantener conversaciones bidireccionales igual que en cualquier aplicación de mensajería.
+
+¿Cómo puede funcionar con colas unidireccionales y sin identificadores de usuario?
+
+2. Cómo funciona la red
+
+Por cada conexión se usan dos colas de mensajes separadas, para que el envío y la recepción se realicen a través de servidores diferentes.
+
+Los servidores sólo transmiten en un sentido para no disponer de la conversación completa o las conexiones del usuario.
+
+3. Qué ven los servidores
+
+Para cada cola los servidores disponen de credenciales separadas y anónimas, por lo que desconocen a qué usuarios pertenecen.
+
+El usuario puede mejorar aún más la privacidad de sus metadatos, haciendo uso de la red Tor para acceder a los servidores, evitando así la correlación por dirección IP.
+
+## Comparación con otros protocolos
+
+|  |  | Signal, grandes plataformas | XMPP, Matrix | Protocolos P2P |
+| --- | --- | --- | --- | --- |
+| Requiere de identidad global | No - privado | Sí [1] | Sí [2] | Sí [3] |
+| Posibilidad de MITM | No - seguro [4] | Sí [5] | Sí | Sí |
+| Dependencia del DNS | No - resiliente | Sí | Sí | No |
+| Red única o centralizada | No - descentralizado | Sí | No - federado [6] | Sí [7] |
+| Componente central u otro ataque en toda la red | No - resiliente | Sí | Sí [2] | Sí [8] |
+
+---
+
+1. Generalmente basada en un número de teléfono, y en algunos casos en nombres de usuario
+2. Direcciones basadas en DNS
+3. Clave pública o algun otro ID único a nivel global
+4. Los servidores no pueden comprometer el cifrado E2E. Para evitar posibles ataques, verifica el código de seguridad mediante un canal alternativo
+5. Si los servidores del operador se ven comprometidos. Verifica el código de seguridad en Signal y otras aplicaciónes para mitigarlo
+6. No protege la privacidad de los metadatos del usuario
+7. A pesar de que las redes P2P son distribuidas, no son federadas. Funcionan como una única red
+8. Las redes P2P, o bien disponen de una autoridad central, o bien la red completa podría verse comprometida — [ver aquí](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparativa del cifrado de extremo a extremo en los distintos mensajeros
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Relleno de mensajes | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudio (negabilidad) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Secreto hacia adelante | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Seguridad tras ser comprometido | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Intercambio de claves de dobre factor | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Cifrado híbrido postcuántico | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar rellena los mensajes hasta el tamaño redondeado a 1024 bytes, Signal a 160 bytes
+2. El repudio no incluye la conexión cliente‑servidor.
+3. Parece que el uso de firmas criptográficas compromete el repudio (negabilidad) pero es necesario aclararlo.
+4. La implementación multi‑dispositivo compromete la seguridad posterior a ser comprometida del Double Ratchet — [ver aquí](https://eprint.iacr.org/2021/626.pdf).
+5. El intercambio de clave de doble factor es opcional mediante la verificación del código de seguridad.
+6. El acuerdo de claves postcuántico es "parcial", solo protege determinados pasos del ratchet.
diff --git a/es/messaging/index.html b/es/messaging/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">La privacidad es completa</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Estás protegido<br>contra el spam y el abuso</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Tu gestionas tus datos</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">La red SimpleX te pertenece</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Permite la entrega de mensajes sin identificadores del perfil de usuario y proporciona mayor privacidad de metadatos que las alternativas.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Para evitarlo las aplicaciones SimpleX pasan claves de un solo uso fuera de banda cuando compartes un enlace de dirección o un código QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Y si el protocolo TLS se ve comprometido, NaCL cryptobox en cada cola de mensajes para prevenir la correlación de tráfico entre las colas.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Si se añade, elimina o modifica algún mensaje, el destinatario es avisado.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Capa de cifrado adicional desde el servidor al destinatario, para prevenir la correlación entre el tráficos de entrada y salida del servidor si el protocolo TLS se ve comprometido.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Los servidores SimpleX actúan como nodos de mezcla de baja latencia, los mensajes entrantes y salientes siguen un orden diferente.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">La reanudación de la conexión está deshabilitada para evitar ataques de sesión.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Para usar SimpleX a través de Tor, instala la aplicación <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot</a> y activa el proxy SOCKS5 (o VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">en iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Esto reduce los vectores de ataque y los metadatos disponibles en comparación con los brokers de mensajes tradicionales.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Esto hace que mensajes de distintos tamaños parezcan iguales desde el punto de vista de servidores y observadores de red.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Pulsa para cerrar</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/old/index.html b/es/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">La privacidad es completa</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Tu gestionas tus datos</h3>
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">La red SimpleX te pertenece</h3>
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-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/es/why.md b/es/why.md
new file mode 100644
index 0000000000..bc2ca35264
--- /dev/null
+++ b/es/why.md
@@ -0,0 +1,19 @@
+# Naciste sin una cuenta.
+
+Nadie monitorizaba tus conversaciones. Nadie registraba tus ubicaciones. La privacidad nunca fue un lujo, era la manera de vivir.
+
+Después pasamos a internet y cada plataforma pedía una parte de tí: tu nombre, tu número, tus amistades. Aceptamos que el precio de hablar con los demás es informar a alguien de quién es interlocutor. Cada generación, personas y tecnología, ha funcionado así: teléfono, email, mensajería, redes sociales. Parecía el único camino.
+
+Existe otro camino. Una red sin números de teléfono. Sin nombres de usuario. Sin cuentas. Sin identificadores de ningún tipo. Una red que conecta las personas y entrega mensajes cifrados sin saber quien está conectado.
+
+No un candado mejorado en la puerta de otro. No un terrateniente que respeta tu privacidad pero sigue guardando un registro de tus visitantes. Tu no eres el invitado. Estás en tu casa y ningún rey podrá entrar. Tu eres el soberano.
+
+Tus conversaciones te pertenecen, tal como ha sido siempre antes de la llegada de internet. Tu red no es un lugar que visitas. Es un lugar que has creado, te pertenece y nadie te la podrá quitar, ya sea pública o privada.
+
+La libertad más antigua del ser humano, la de hablar con otra persona sin ser observado, materializada sobre una infraestructura que no puede traicionarla.
+
+Porque hemos destruido el poder de saber quien eres. De manera que *tu* poder nunca se pueda arrebatar.
+
+Se libre en tu red.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/es/why/index.html b/es/why/index.html
index e506c96f51..7b52cf86c2 100644
--- a/es/why/index.html
+++ b/es/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/es/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Se libre en tu red.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/fa/contact.md b/fa/contact.md
new file mode 100644
index 0000000000..5fcdbc64b7
--- /dev/null
+++ b/fa/contact.md
@@ -0,0 +1,66 @@
+# شما یک آدرس برای اتصال به چت SimpleX دریافت کرده‌اید
+
+## کد QR را با برنامه چت SimpleX روی گوشی یا تبلت خود اسکن کنید.
+
+کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند — آن‌ها در بخش هش لینک URL قرار دارند.
+
+هنوز برنامه چت SimpleX را دانلود نکرده‌اید؟
+
+از لینک‌های زیر برای دانلود برنامه استفاده کنید.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+کد QR را از برنامه موبایل اسکن کنید
+
+# شما یک آدرس برای اتصال به چت SimpleX دریافت کرده‌اید
+
+برای برقراری ارتباط:
+
+برنامه SimpleX را نصب کنید
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid)
+
+1
+
+در برنامه متصل شوید
+
+برنامه SimpleX را باز کنید
+
+2
+
+دکمه ‘اتصال’ را در برنامه بزنید
+
+3
+
+## کد QR را با برنامه چت SimpleX اسکن کنید
+
+کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند —
+آن‌ها در بخش هش لینک URL قرار دارند.
+
+## نصب چت SimpleX در ترمینال
+
+از این دستور استفاده کنید:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+چت SimpleX را ببینید مخزن GitHub برای دستورالعمل‌های دانلود یا کامپایل آن از کد منبع.
+
+---
+
+## اگر قبلاً چت SimpleX را برای ترمینال نصب کرده‌اید
+
+اگر قبلاً نصب کرده‌اید چت SimpleX برای ترمینال v1.0.0+, دستور زیر را کپی کرده و در چت استفاده کنید:
+
+## پیوستن SimpleX
+
+ما شما را به پیوستن به گفتگو دعوت می‌کنیم
+
+[به جامعه REDDIT بپیوندید](https://www.reddit.com/r/SimpleXChat/) [به ما در GitHub بپیوندید](https://github.com/simplex-chat) [اینجا حمایت مالی کنید](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+برای دریافت به‌روزرسانی‌های ما ثبت‌نام کنید
+
+---
+
+برنامه [دسکتاپ SimpleX](https://simplex.chat/downloads) را دریافت کنید
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid)
diff --git a/fa/contact/index.html b/fa/contact/index.html
index 4113385b35..7390e9b89a 100644
--- a/fa/contact/index.html
+++ b/fa/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">شما یک آدرس برای اتصال به چت SimpleX دریافت کرده‌اید</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">کد QR را با برنامه چت SimpleX روی گوشی یا تبلت خود اسکن کنید.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند — آن‌ها در بخش هش لینک URL قرار دارند.
+                کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند &mdash; آن‌ها در بخش هش لینک URL قرار دارند.
             </p>
             <p class="text-grey-black dark:text-white text-base">هنوز برنامه چت SimpleX را دانلود نکرده‌اید؟</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">از لینک‌های زیر برای دانلود برنامه استفاده کنید.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">برنامه SimpleX را نصب کنید</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -748,7 +755,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">دکمه <span class="text-active-blue">‘اتصال’</span> را در برنامه بزنید</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">دکمه <span class='text-active-blue'>‘اتصال’</span> را در برنامه بزنید</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">کد QR را با برنامه چت SimpleX اسکن کنید</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند —<br> آن‌ها در بخش هش لینک URL قرار دارند.
+                            کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند &mdash;<br> آن‌ها در بخش هش لینک URL قرار دارند.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">نصب چت SimpleX در ترمینال</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">مخزن GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">اگر قبلاً چت SimpleX را برای ترمینال نصب کرده‌اید</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">برای دریافت به‌روزرسانی‌های ما ثبت‌نام کنید</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="آدرس ایمیل خود را وارد کنید">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">برنامه <a href="/downloads">دسکتاپ SimpleX</a> را دریافت کنید</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/fdroid.md b/fa/fdroid.md
new file mode 100644
index 0000000000..a5befc6bd6
--- /dev/null
+++ b/fa/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat در F-Droid
+
+### مخزن SimpleX Chat
+
+نسخه‌های پایدار و بتا که توسط توسعه‌دهندگان ساخته شده‌اند
+
+برای افزودن آن به کلاینت F-Droid خود، کد QR را اسکن کنید یا از این URL استفاده کنید:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+اثر انگشت کلید امضا (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### مخزن F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+نسخه‌های پایدار که توسط F-Droid.org ساخته شده‌اند
+
+انتشارها در این مخزن چندین روز بعد انجام می‌شود.
+
+SimpleX Chat و مخازن F-Droid.org بیلدها را با کلیدهای متفاوتی امضا می‌کنند. برای تغییر، لطفاً [پایگاه داده چت را اکسپورت کنید](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) و برنامه را دوباره نصب کنید.
diff --git a/fa/fdroid/index.html b/fa/fdroid/index.html
index 7c0eafc214..2232ebd08f 100644
--- a/fa/fdroid/index.html
+++ b/fa/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat در F-Droid</h2>
 
@@ -692,16 +697,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">نسخه‌های پایدار و بتا که توسط توسعه‌دهندگان ساخته شده‌اند</p>
-                        <p>برای افزودن آن به کلاینت F-Droid خود، <span class="hide-on-mobile">کد QR را اسکن کنید یا</span> از این URL استفاده کنید:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>برای افزودن آن به کلاینت F-Droid خود، <span class='hide-on-mobile'>کد QR را اسکن کنید یا</span> از این URL استفاده کنید:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             اثر انگشت کلید امضا (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,25 +718,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">مخزن F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">نسخه‌های پایدار که توسط F-Droid.org ساخته شده‌اند</p>
                 <p class="mb-2">انتشارها در این مخزن چندین روز بعد انجام می‌شود.</p>
-                <p class="mb-2">SimpleX Chat و مخازن F-Droid.org بیلدها را با کلیدهای متفاوتی امضا می‌کنند. برای تغییر، لطفاً <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">پایگاه داده چت را اکسپورت کنید</a> و برنامه را دوباره نصب کنید.</p>
+                <p class="mb-2">SimpleX Chat و مخازن F-Droid.org بیلدها را با کلیدهای متفاوتی امضا می‌کنند. برای تغییر، لطفاً <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>پایگاه داده چت را اکسپورت کنید</a> و برنامه را دوباره نصب کنید.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/file.md b/fa/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/fa/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/fa/file/index.html b/fa/file/index.html
index 4aa8ca444e..5dba82dabf 100644
--- a/fa/file/index.html
+++ b/fa/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/index.html b/fa/index.html
index b389165c73..1616217418 100644
--- a/fa/index.html
+++ b/fa/index.html
@@ -60,6 +60,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/fa/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/fa/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/fa/index.md b/fa/index.md
new file mode 100644
index 0000000000..c6a328c326
--- /dev/null
+++ b/fa/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# آزاد باش
+
+## در شبکه شما
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [بیشتر بدانید.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/fa/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/fa/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/fa/why)
+
+## با حمایت مالی کاربران
+
+برای حفظ استقلال، کانال‌ها و انجمن‌های بزرگ هزینه سرورهای خود را می‌پردازند.
+
+و اکنون کاربران می‌توانند در SimpleX Chat سرمایه‌گذاری کنند — تأمین مالی جمعی آغاز شده است!
+
+[در SimpleX Chat سرمایه‌گذاری کنید](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/fa/invitation.md b/fa/invitation.md
new file mode 100644
index 0000000000..19b35cb1d1
--- /dev/null
+++ b/fa/invitation.md
@@ -0,0 +1,66 @@
+# شما یک لینک یک‌بار مصرف برای اتصال به چت SimpleX دریافت کرده‌اید
+
+## کد QR را با برنامه چت SimpleX روی گوشی یا تبلت خود اسکن کنید.
+
+کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند — آن‌ها در بخش هش لینک URL قرار دارند.
+
+هنوز برنامه چت SimpleX را دانلود نکرده‌اید؟
+
+از لینک‌های زیر برای دانلود برنامه استفاده کنید.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+کد QR را از برنامه موبایل اسکن کنید
+
+# شما یک لینک یک‌بار مصرف برای اتصال به چت SimpleX دریافت کرده‌اید
+
+برای برقراری ارتباط:
+
+برنامه SimpleX را نصب کنید
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid)
+
+1
+
+در برنامه متصل شوید
+
+برنامه SimpleX را باز کنید
+
+2
+
+دکمه ‘اتصال’ را در برنامه بزنید
+
+3
+
+## کد QR را با برنامه چت SimpleX اسکن کنید
+
+کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند —
+آن‌ها در بخش هش لینک URL قرار دارند.
+
+## نصب چت SimpleX در ترمینال
+
+از این دستور استفاده کنید:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+چت SimpleX را ببینید مخزن GitHub برای دستورالعمل‌های دانلود یا کامپایل آن از کد منبع.
+
+---
+
+## اگر قبلاً چت SimpleX را برای ترمینال نصب کرده‌اید
+
+اگر قبلاً نصب کرده‌اید چت SimpleX برای ترمینال v1.0.0+, دستور زیر را کپی کرده و در چت استفاده کنید:
+
+## پیوستن SimpleX
+
+ما شما را به پیوستن به گفتگو دعوت می‌کنیم
+
+[به جامعه REDDIT بپیوندید](https://www.reddit.com/r/SimpleXChat/) [به ما در GitHub بپیوندید](https://github.com/simplex-chat) [اینجا حمایت مالی کنید](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+برای دریافت به‌روزرسانی‌های ما ثبت‌نام کنید
+
+---
+
+برنامه [دسکتاپ SimpleX](https://simplex.chat/downloads) را دریافت کنید
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fa/fdroid)
diff --git a/fa/invitation/index.html b/fa/invitation/index.html
index 66ccfd8992..6843fb7c19 100644
--- a/fa/invitation/index.html
+++ b/fa/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">شما یک لینک یک‌بار مصرف برای اتصال به چت SimpleX دریافت کرده‌اید</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">کد QR را با برنامه چت SimpleX روی گوشی یا تبلت خود اسکن کنید.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند — آن‌ها در بخش هش لینک URL قرار دارند.
+                کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند &mdash; آن‌ها در بخش هش لینک URL قرار دارند.
             </p>
             <p class="text-grey-black dark:text-white text-base">هنوز برنامه چت SimpleX را دانلود نکرده‌اید؟</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">از لینک‌های زیر برای دانلود برنامه استفاده کنید.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">برنامه SimpleX را نصب کنید</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -748,7 +755,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">دکمه <span class="text-active-blue">‘اتصال’</span> را در برنامه بزنید</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">دکمه <span class='text-active-blue'>‘اتصال’</span> را در برنامه بزنید</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">کد QR را با برنامه چت SimpleX اسکن کنید</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند —<br> آن‌ها در بخش هش لینک URL قرار دارند.
+                            کلیدهای عمومی و آدرس صف پیام در این لینک هنگام مشاهده این صفحه از طریق شبکه ارسال نمی‌شوند &mdash;<br> آن‌ها در بخش هش لینک URL قرار دارند.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">نصب چت SimpleX در ترمینال</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">مخزن GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">اگر قبلاً چت SimpleX را برای ترمینال نصب کرده‌اید</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">برای دریافت به‌روزرسانی‌های ما ثبت‌نام کنید</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="آدرس ایمیل خود را وارد کنید">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">برنامه <a href="/downloads">دسکتاپ SimpleX</a> را دریافت کنید</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/messaging.md b/fa/messaging.md
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--- /dev/null
+++ b/fa/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## چرا SimpleX منحصربه‌فرد است
+
+### شما حریم خصوصی کاملی دارید
+
+SimpleX حریم خصوصی پروفایل، مخاطبین و فراداده‌های شما را محافظت می‌کند و آن‌ها را از سرورهای شبکه SimpleX و هر ناظر دیگری پنهان می‌سازد.
+
+برخلاف هر شبکه پیام‌رسان دیگری، SimpleX هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد — **حتی شماره‌های تصادفی** نیز وجود ندارد.
+
+### شما از هرزنامه و سوءاستفاده محافظت می‌شوید
+
+از آنجا که شما هیچ شناسه یا آدرس ثابتی در شبکه SimpleX ندارید، هیچ‌کس نمی‌تواند با شما تماس بگیرد مگر اینکه یک آدرس کاربری یک‌بار مصرف یا موقتی را به‌عنوان کد QR یا لینک به اشتراک بگذارید.
+
+### شما بر داده‌های خود کنترل دارید
+
+SimpleX تمام داده‌های کاربری را بر روی دستگاه‌های کلاینت در یک **فرمت پایگاه داده رمزنگاری شده قابل حمل** ذخیره می‌کند — این داده‌ها می‌توانند به دستگاه دیگری منتقل شوند.
+
+پیام‌های رمزنگاری شده انتها به انتها به‌طور موقت بر روی سرورهای رله SimpleX نگهداری می‌شوند تا دریافت شوند و سپس به‌طور دائمی حذف می‌شوند.
+
+### ­شما مالک شبکه SimpleX هستید
+
+شبکه SimpleX به‌طور کامل غیرمتمرکز و مستقل از هر ارز دیجیتال یا هر شبکه دیگری به جز اینترنت است.
+
+شما می‌توانید **از SimpleX با سرورهای خود استفاده کنید** یا از سرورهای ارائه‌شده توسط ما استفاده کنید — و همچنان به هر کاربری متصل شوید.
+
+# حریم خصوصی کامل هویت، پروفایل، مخاطبین و فراداده‌های شما
+
+برخلاف سایر شبکه‌های پیام‌رسان، SimpleX **هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد**. این شبکه به شماره‌های تلفن، آدرس‌های مبتنی بر دامنه (مانند ایمیل یا XMPP)، نام‌های کاربری، کلیدهای عمومی یا حتی شماره‌های تصادفی برای شناسایی کاربران خود تکیه نمی‌کند — اپراتورهای سرور SimpleX نمی‌دانند چند نفر از سرورهای آن‌ها استفاده می‌کنند.
+
+برای ارسال پیام‌ها، SimpleX از [آدرس‌های ناشناس جفتی](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) در صف‌های پیام یک‌طرفه استفاده می‌کند که برای پیام‌های دریافتی و ارسال‌شده جداگانه هستند و معمولاً از طریق سرورهای مختلف انجام می‌شود.
+
+این طراحی از حریم خصوصی افرادی را که با آن‌ها ارتباط دارید، محافظت می‌کند و آن را از سرورهای شبکه SimpleX و هر ناظر دیگری پنهان می‌سازد. برای پنهان کردن آدرس IP خود از سرورها، می‌توانید **از طریق Tor به سرورهای SimpleX متصل شوید**.
+
+# بهترین محافظت در برابر هرزنامه و سوءاستفاده
+
+از آنجایی که شما هیچ شناسه‌ای در شبکه SimpleX ندارید، هیچ‌کس نمی‌تواند با شما تماس بگیرد مگر اینکه یک آدرس کاربری یک‌بار مصرف یا موقتی را به‌عنوان کد QR یا لینک به اشتراک بگذارید.
+
+حتی با وجود آدرس کاربری اختیاری که ممکن است برای ارسال درخواست‌های تماس اسپم استفاده شود، شما می‌توانید آن را تغییر دهید یا به‌طور کامل حذف کنید و در عین حال هیچ‌یک از ارتباطات خود را از دست ندهید.
+
+# مالکیت، کنترل و امنیت داده‌های شما
+
+چت SimpleX تمام داده‌های کاربری را تنها بر روی دستگاه‌های کلاینت ذخیره می‌کند و از یک **فرمت پایگاه داده رمزنگاری شده قابل حمل** استفاده می‌کند که می‌تواند اکسپورت و به هر دستگاه پشتیبانی‌شده‌ای منتقل شود.
+
+پیام‌های رمزنگاری شده انتها به انتها به‌طور موقت بر روی سرورهای رله SimpleX نگهداری می‌شوند تا دریافت شوند و سپس به‌طور دائمی حذف می‌شوند.
+
+برخلاف سرورهای شبکه‌های فدرال (ایمیل، XMPP یا Matrix)، سرورهای SimpleX حساب‌های کاربری را ذخیره نمی‌کنند و تنها پیام‌ها را منتقل می‌کنند، که حریم خصوصی هر دو طرف را محافظت می‌کند.
+
+هیچ شناسه یا متن رمز مشترکی بین ترافیک سرور ارسال‌شده و دریافتی وجود ندارد — اگر کسی در حال نظارت باشد، نمی‌تواند به‌راحتی تشخیص دهد که چه کسی با چه کسی ارتباط برقرار می‌کند، حتی اگر TLS به خطر بیفتد.
+
+# کاملاً غیرمتمرکز — کاربران مالک شبکه SimpleX هستند
+
+شما می‌توانید **از SimpleX با سرورهای خود استفاده کنید** و همچنان با افرادی که از سرورهای پیش‌پیکربندی‌شده در برنامه‌ها استفاده می‌کنند، ارتباط برقرار کنید.
+
+شبکه SimpleX از یک [پروتکل باز](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) استفاده می‌کند و [SDK برای ایجاد ربات‌های چت](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript) ارائه می‌دهد، که امکان پیاده‌سازی خدماتی را فراهم می‌کند که کاربران می‌توانند از طریق برنامه‌های چت SimpleX با آن‌ها تعامل داشته باشند — ما واقعاً منتظر هستیم ببینیم چه خدماتی را با SimpleX ایجاد خواهید کرد.
+
+اگر به توسعه برای شبکه SimpleX فکر می‌کنید، مثلاً ربات چت برای کاربران برنامه SimpleX یا ادغام کتابخانه چت SimpleX در برنامه‌های موبایل خود، لطفاً برای هرگونه مشاوره و پشتیبانی [با ما تماس بگیرید](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D).
+
+## ویژگی‌ها
+
+پیام‌های رمزنگاری شده انتها به انتها با ویرایش و فرمت‌بندی Markdown
+
+تصاویر، ویدیوها و فایل‌های رمزنگاری شده انتها به انتها
+
+گروه‌های غیرمتمرکز رمزنگاری شده انتها به انتها — تنها کاربران می‌دانند که این گروه‎ها وجود دارند
+
+پیام‌های صوتی رمزنگاری شده به صورت انتها به انتها
+
+پیام‌های ناپدید شونده
+
+تماس‌های صوتی و ویدیویی رمزنگاری شده انتها به انتها
+
+فضای ذخیره‌سازی رمزنگاری شده قابل حمل — انتقال پروفایل به دستگاه دیگر
+
+حالت ناشناس —
+منحصربه‌فرد برای SimpleX Chat
+
+## چه چیزی SimpleX را خصوصی می‌کند
+
+### شناسه‌های موقت ناشناس دوطرفه
+
+SimpleX از آدرس‌ها و اعتبارنامه‌های موقتی و ناشناس جفت‌به‌جفت برای هر مخاطب کاربر یا عضو گروه استفاده می‌کند.
+
+این امکان را فراهم می‌کند که پیام‌ها بدون شناسه‌های پروفایل کاربر ارسال شوند و حریم خصوصی فراداده بهتری نسبت به گزینه‌های دیگر ارائه می‌دهد.
+
+### مبادله کلید خارج از باند
+
+بسیاری از شبکه‌های ارتباطی در برابر حملات MITM توسط سرورها یا ارائه‌دهندگان شبکه آسیب‌پذیر هستند.
+
+زمانی که آدرسی را به عنوان لینک یا کد QR به اشتراک می‌گذارید، برنامه‌های SimpleX کلیدهای یک‌بار مصرف را به صورت خارج از باند منتقل می‌کنند تا از این موضوع جلوگیری شود.
+
+### دو لایه از رمزنگاری انتها به انتها
+
+پروتکل Double-ratchet — پیام‌رسانی OTR با محرمانگی کامل پیشرو و بازیابی در صورت نفوذ.
+
+NaCL cryptobox در هر صف برای جلوگیری از همبستگی ترافیک بین صف‌های پیام اگر TLS به خطر بیفتد.
+
+### تأیید صحت پیام
+
+برای تضمین یکپارچگی، پیام‌ها به صورت ترتیبی شماره‌گذاری شده و شامل هش پیام قبلی هستند.
+
+اگر هر پیامی اضافه، حذف یا تغییر یابد، گیرنده مطلع خواهد شد.
+
+### لایه اضافی از رمزنگاری سرور
+
+برای تحویل به گیرنده، لایه اضافی رمزنگاری سرور اضافه می‌شود تا در صورت به خطر افتادن TLS، از همبستگی بین ترافیک دریافتی و ارسالی سرور جلوگیری شود.
+
+### مخلوط‌سازی پیام برای کاهش امکان رهگیری
+
+سرورهای SimpleX به عنوان گره‌های میکس با تأخیر کم عمل می‌کنند — پیام‌های ورودی و خروجی ترتیب متفاوتی دارند.
+
+### انتقال TLS امن و تأییدشده
+
+فقط از TLS 1.2/1.3 با الگوریتم‌های قوی برای اتصالات کلاینت-سرور استفاده می‌شود.
+
+اثر انگشت سرور و اتصال کانال از حملات MITM و حملات replay جلوگیری می‌کنند.
+
+برای جلوگیری از حملات نشست، از سرگیری اتصال غیرفعال شده است.
+
+### دسترسی اختیاری از طریق Tor
+
+برای محافظت از آدرس IP خود، می‌توانید از طریق Tor یا برخی دیگر از شبکه‌های حمل و نقل پوششی به سرورها دسترسی پیدا کنید.
+
+برای استفاده از SimpleX از طریق Tor، لطفاً [برنامه Orbot](https://guardianproject.info/apps/org.torproject.android/) را نصب کرده و پروکسی SOCKS5 (یا VPN [در iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)) را فعال کنید.
+
+### صف‌های پیام یک‌طرفه
+
+هر صف پیام، پیام‌ها را در یک جهت منتقل می‌کند و آدرس‌های ارسال و دریافت متفاوتی دارد.
+
+این کار نسبت به کارگزارهای پیام سنتی و فراداده‌های موجود، بردارهای حمله را کاهش می‌دهد.
+
+### چندین لایه از پدینگ محتوا
+
+SimpleX از padding محتوا برای هر لایه رمزنگاری استفاده می‌کند تا از حملات اندازه پیام جلوگیری کند.
+
+این کار باعث می‌شود که پیام‌های با اندازه‌های مختلف برای سرورها و ناظران شبکه یکسان به نظر برسند.
+
+## شبکه SimpleX
+
+چت SimpleX بهترین حریم خصوصی را با ترکیب مزایای شبکه‌های P2P و شبکه‌های فدرال ارائه می‌دهد.
+
+### برخلاف شبکه‌های P2P
+
+تمام پیام‌ها از طریق سرورها ارسال می‌شوند که هم حریم خصوصی فراداده را بهتر تأمین می‌کند و هم تحویل پیام‌های غیرهمزمان قابل اعتماد را فراهم می‌آورد، در حالی که از بسیاری از مشکلات جلوگیری می‌کند. .
+
+# مقایسه با پروتکل‌های پیام‌رسانی P2P
+
+پروتکل‌ها و برنامه‌های پیام‌رسانی [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) مشکلات متعددی دارند که آن‌ها را نسبت به SimpleX کمتر قابل اعتماد، تحلیل آن‌ها را پیچیده‌تر و در برابر چندین نوع حمله آسیب‌پذیر می‌کند.
+
+1. شبکه‌های P2P به نوعی از [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) برای مسیریابی پیام‌ها وابسته هستند. طراحی‌های DHT باید بین تضمین تحویل و تأخیر تعادل برقرار کنند. SimpleX هم تضمین تحویل بهتری دارد و هم تأخیر کمتری نسبت به P2P، زیرا پیام می‌تواند به صورت اضافی از طریق چندین سرور به طور موازی منتقل شود و از سرورهای انتخاب‌شده توسط گیرنده استفاده کند. در شبکه‌های P2P، پیام به صورت ترتیبی از طریق *O(log N)* گره منتقل می‌شود و این گره‌ها توسط الگوریتم انتخاب می‌شوند.
+2. طراحی SimpleX، برخلاف اکثر شبکه‌های P2P، هیچ شناسه کاربری جهانی از هیچ نوعی، حتی موقتی، ندارد و فقط از شناسه‌های جفت‌به‌جفت موقتی استفاده می‌کند که این امر حریم خصوصی و محافظت از فراداده را بهتر فراهم می‌کند.
+3. P2P مشکل [حملات MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) را حل نمی‌کند و بیشتر پیاده‌سازی‌های موجود از پیام‌های خارج از باند برای تبادل کلید اولیه استفاده نمی‌کنند. SimpleX از پیام‌های خارج از باند یا در برخی موارد، از اتصالات امن و مورد اعتماد پیشین برای تبادل کلید اولیه استفاده می‌کند.
+4. پیاده‌سازی‌های P2P می‌توانند توسط برخی از ارائه‌دهندگان اینترنت (مانند [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)) مسدود شوند. SimpleX مستقل از نوع حمل و نقل است — این امکان را دارد که بر روی پروتکل‌های وب استاندارد، مانند WebSockets، کار کند.
+5. تمام شبکه‌های P2P شناخته‌شده ممکن است در معرض [حمله Sybil](https://en.wikipedia.org/wiki/Sybil_attack) قرار بگیرند، زیرا هر گره قابل شناسایی است و شبکه به‌عنوان یک کل عمل می‌کند. تدابیر شناخته‌شده برای کاهش آن نیاز به یک مؤلفه متمرکز یا [اثبات کار](https://en.wikipedia.org/wiki/Proof_of_work) پرهزینه دارند. شبکه SimpleX هیچ کشف‌پذیری سروری ندارد، تکه‌تکه است و به‌عنوان چندین زیرشبکه ایزوله عمل می‌کند، که حملات در سطح شبکه را غیرممکن می‌سازد.
+6. شبکه‌های P2P ممکن است در معرض [حمله DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) قرار بگیرند، زمانی که کلاینت‌ها می‌توانند ترافیک را دوباره پخش و تقویت کنند که منجر به عدم دسترسی به خدمات در سطح شبکه می‌شود. کلاینت‌های SimpleX تنها ترافیک را از اتصالات شناخته‌شده منتقل می‌کنند و نمی‌توانند توسط یک مهاجم برای تقویت ترافیک در کل شبکه استفاده شوند.
+
+---
+
+### برخلاف شبکه‌های فدرال
+
+سرورهای رله SimpleX پروفایل‌های کاربری، مخاطبین و پیام‌های تحویل‌شده را ذخیره نمی‌کنند، به یکدیگر متصل نمی‌شوند و هیچ دایرکتوری سروری وجود ندارد.
+
+---
+
+### شبکه SimpleX
+
+سرورها صف‌های یک‌طرفه را برای اتصال کاربران فراهم می‌کنند، اما هیچ دیدگاهی از نمودار ارتباطات شبکه ندارند — تنها کاربران این دید را دارند.
+
+## توضیحات در مورد SimpleX
+
+۱. تجربه کاربران
+
+۲. چگونه کار می‌کند
+
+۳. آنچه سرورها می‌بینند
+
+۱. تجربه کاربران
+
+شما می‌توانید مخاطبین و گروه‌ها را ایجاد کنید و مانند هر پیام‌رسان دیگری، مکالمات دوطرفه داشته باشید.
+
+چگونه می‌تواند با صف‌های یک‌طرفه و بدون شناسه‌های پروفایل کاربر کار کند؟
+
+۲. چگونه کار می‌کند
+
+برای هر اتصال، شما از دو صف پیام جداگانه برای ارسال و دریافت پیام‌ها از طریق سرورهای مختلف استفاده می‌کنید.
+
+سرورها فقط پیام‌ها را به یک سمت منتقل می‌کنند و از جزئیات کامل مکالمات یا ارتباطات کاربران بی‌خبر هستند.
+
+۳. آنچه سرورها می‌بینند
+
+سرورها برای هر صف دارای اعتبارنامه‌های جداگانه و ناشناس هستند و نمی‌دانند که این اعتبارنامه‌ها به کدام کاربران تعلق دارند.
+
+کاربران می‌توانند با استفاده از Tor برای دسترسی به سرورها، حریم خصوصی فراداده را بیشتر بهبود بخشند و از شناسایی بر اساس آدرس IP جلوگیری کنند.
+
+## مقایسه با سایر پروتکل‌ها
+
+|  |  | سیگنال، پلتفرم‌های بزرگ | XMPP، Matrix | پروتکل‌های P2P |
+| --- | --- | --- | --- | --- |
+| نیاز به هویت جهانی دارد | خیر - خصوصی | بله [1] | بله [2] | بله [3] |
+| امکان حمله MITM | خیر - امن [4] | بله [5] | بله | بله |
+| وابستگی به DNS | خیر - مقاوم | بله | بله | خیر |
+| شبکه تک یا متمرکز | خیر - غیرمتمرکز | بله | خیر - فدرال [6] | بله [7] |
+| مؤلفه مرکزی یا حمله‌ای در سطح شبکه | خیر - مقاوم | بله | بله [2] | بله [8] |
+
+---
+
+1. معمولاً بر اساس شماره تلفن و در برخی موارد بر اساس نام‌های کاربری
+2. آدرس‌های مبتنی بر DNS
+3. کلید عمومی یا برخی دیگر از شناسه‌های منحصربه‌فرد جهانی
+4. رله‌های SimpleX نمی‌توانند رمزنگاری انتها به انتها را به خطر بیندازند. توصیه می‌شود کد امنیتی را برای کاهش حمله در کانال out-of-band تأیید کنید
+5. اگر سرورهای اپراتور به خطر بیفتند. کد امنیتی را در سیگنال و برخی دیگر از برنامه‌ها تأیید کنید تا این خطر را کاهش دهید
+6. از حریم خصوصی فراداده‌های کاربران محافظت نمی‌کند
+7. در حالی که شبکه‌های P2P توزیع‌شده هستند، اما فدرال نیستند — آن‌ها به‌عنوان یک شبکه واحد عمل می‌کنند
+8. شبکه‌های P2P یا دارای یک نهاد مرکزی هستند یا کل شبکه می‌تواند به خطر بیفتد — [اینجا را ببینید](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [اینجا را ببینید](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/fa/messaging/index.html b/fa/messaging/index.html
index bbd86fabd2..aca06e6e24 100644
--- a/fa/messaging/index.html
+++ b/fa/messaging/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما حریم خصوصی کاملی دارید</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما از هرزنامه و سوءاستفاده محافظت می‌شوید</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما بر داده‌های خود کنترل دارید</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">­شما مالک شبکه SimpleX هستید</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">این امکان را فراهم می‌کند که پیام‌ها بدون شناسه‌های پروفایل کاربر ارسال شوند و حریم خصوصی فراداده بهتری نسبت به گزینه‌های دیگر ارائه می‌دهد.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">زمانی که آدرسی را به عنوان لینک یا کد QR به اشتراک می‌گذارید، برنامه‌های SimpleX کلیدهای یک‌بار مصرف را به صورت خارج از باند منتقل می‌کنند تا از این موضوع جلوگیری شود.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1236,7 +1240,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox در هر صف برای جلوگیری از همبستگی ترافیک بین صف‌های پیام اگر TLS به خطر بیفتد.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1254,7 +1258,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">اگر هر پیامی اضافه، حذف یا تغییر یابد، گیرنده مطلع خواهد شد.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1270,7 +1274,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">برای تحویل به گیرنده، لایه اضافی رمزنگاری سرور اضافه می‌شود تا در صورت به خطر افتادن TLS، از همبستگی بین ترافیک دریافتی و ارسالی سرور جلوگیری شود.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1286,7 +1290,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">سرورهای SimpleX به عنوان گره‌های میکس با تأخیر کم عمل می‌کنند — پیام‌های ورودی و خروجی ترتیب متفاوتی دارند.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1306,7 +1310,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">برای جلوگیری از حملات نشست، از سرگیری اتصال غیرفعال شده است.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">برای استفاده از SimpleX از طریق Tor، لطفاً <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">برنامه Orbot</a> را نصب کرده و پروکسی SOCKS5 (یا VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">در iOS</a>) را فعال کنید.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1342,7 +1346,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">این کار نسبت به کارگزارهای پیام سنتی و فراداده‌های موجود، بردارهای حمله را کاهش می‌دهد.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1360,7 +1364,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">این کار باعث می‌شود که پیام‌های با اندازه‌های مختلف برای سرورها و ناظران شبکه یکسان به نظر برسند.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">برای بستن ضربه بزنید</p>
                     </div>
                 </div>
                 
@@ -1842,17 +1846,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/old/index.html b/fa/old/index.html
index 65e390984d..51f88b86b7 100644
--- a/fa/old/index.html
+++ b/fa/old/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,13 +674,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">حریم خصوصی بازتعریف شده</h1>
@@ -721,7 +726,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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     </div>
@@ -752,7 +757,7 @@ window.addEventListener('click',(e)=>{
     فقط دستگاه‌های کلاینت پروفایل‌های کاربری، مخاطبین و گروه‌ها را ذخیره می‌کنند؛ پیام‌ها با رمزنگاری انتها به انتهای دو لایه ارسال می‌شوند.
 </p>
 <p>
-    برای اطلاعات بیشتر به <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">وایت پیپر SimpleX</a> مراجعه کنید.
+    برای اطلاعات بیشتر به <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>وایت پیپر SimpleX</a> مراجعه کنید.
 </p>
                         </div>
                     </div>
@@ -769,7 +774,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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@@ -808,7 +813,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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@@ -829,7 +834,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -845,11 +850,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">برنامه <a href="/downloads">دسکتاپ SimpleX</a> را دریافت کنید</p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -860,15 +865,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -897,10 +902,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -922,8 +927,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">چرا حریم خصوصی <span class="gradient-text">مهم است</span></h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">حفظ حریم خصوصی فراداده‌های شما — <span class="text-active-blue">با چه کسی صحبت می‌کنید</span> — شما را در برابر موارد زیر محافظت می‌کند:</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">چرا حریم خصوصی <span class='gradient-text'>مهم است</span></h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">حفظ حریم خصوصی فراداده‌های شما &mdash; <span class='text-active-blue'>با چه کسی صحبت می‌کنید</span> &mdash; شما را در برابر موارد زیر محافظت می‌کند:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -951,7 +956,7 @@ window.addEventListener('click',(e)=>{
     فروشگاه‌های آنلاین می‌دانند که افراد با درآمد پایین‌تر بیشتر احتمال دارد خریدهای فوری انجام دهند، بنابراین ممکن است قیمت‌های بالاتری تعیین کنند یا تخفیف‌ها را حذف کنند.
 </p>
 <p>
-    برخی از شرکت‌های مالی و بیمه از نمودارهای اجتماعی برای تعیین نرخ‌های بهره و حق بیمه‌ها استفاده می‌کنند. این اغلب باعث می‌شود که افراد با درآمد پایین‌تر بیشتر پرداخت کنند — که به آن <a href="https://fairbydesign.com/povertypremium/" target="_blank">'حق بیمه فقر'</a> گفته می‌شود.
+    برخی از شرکت‌های مالی و بیمه از نمودارهای اجتماعی برای تعیین نرخ‌های بهره و حق بیمه‌ها استفاده می‌کنند. این اغلب باعث می‌شود که افراد با درآمد پایین‌تر بیشتر پرداخت کنند &mdash; که به آن <a href='https://fairbydesign.com/povertypremium/' target='_blank'>'حق بیمه فقر'</a> گفته می‌شود.
 </p>
 <p>
     شبکه SimpleX حریم خصوصی ارتباطات شما را بهتر از هر گزینه دیگری محافظت می‌کند و به‌طور کامل از در دسترس قرار گرفتن نمودار اجتماعی شما برای هر شرکت یا سازمانی جلوگیری می‌کند. حتی زمانی که افراد از سرورهای پیش‌پیکربندی‌شده در برنامه‌های چت SimpleX استفاده می‌کنند، اپراتورهای سرور از تعداد کاربران یا ارتباطات آن‌ها اطلاعی ندارند.
@@ -965,7 +970,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -992,7 +997,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    مدتی پیش، ما شاهد دستکاری در انتخابات بزرگ توسط <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">یک شرکت مشاوره معتبر</a> بودیم که از نمودارهای اجتماعی ما برای تحریف دیدگاه‌مان نسبت به دنیای واقعی و دستکاری در رأی‌گیری‌مان استفاده کرد.
+    مدتی پیش، ما شاهد دستکاری در انتخابات بزرگ توسط <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>یک شرکت مشاوره معتبر</a> بودیم که از نمودارهای اجتماعی ما برای تحریف دیدگاه‌مان نسبت به دنیای واقعی و دستکاری در رأی‌گیری‌مان استفاده کرد.
 </p>
 <p>
     برای اینکه عینی باشید و تصمیمات مستقل بگیرید، باید کنترل فضای اطلاعات خود را در دست داشته باشید. این تنها در صورتی ممکن است که از یک شبکه ارتباطی خصوصی استفاده کنید که به نمودار اجتماعی شما دسترسی نداشته باشد.
@@ -1009,7 +1014,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1036,16 +1041,16 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    همه باید به حریم خصوصی و امنیت ارتباطات خود اهمیت دهند — گفتگوهای بی‌ضرر می‌توانند شما را در خطر قرار دهند، حتی اگر چیزی برای پنهان کردن نداشته باشید.
+    همه باید به حریم خصوصی و امنیت ارتباطات خود اهمیت دهند &mdash; گفتگوهای بی‌ضرر می‌توانند شما را در خطر قرار دهند، حتی اگر چیزی برای پنهان کردن نداشته باشید.
 </p>
 <p>
-    یکی از شگفت‌انگیزترین داستان‌ها، تجربه <a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">محمدو ولد صلاحی</a> است که در یادداشت‌هایش توصیف شده و در فیلم "موریتانی" به نمایش درآمده است. او بدون محاکمه به اردوگاه گوانتانامو منتقل شد و به مدت ۱۵ سال تحت شکنجه قرار گرفت. این اتفاق پس از یک تماس تلفنی با یکی از بستگانش در افغانستان رخ داد. او به ظن ارتباط با حملات ۱۱ سپتامبر، بدون محاکمه به اردوگاه گوانتانامو منتقل شد.
+    یکی از شگفت‌انگیزترین داستان‌ها، تجربه <a href='https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi' target='_blank'>محمدو ولد صلاحی</a> است که در یادداشت‌هایش توصیف شده و در فیلم "موریتانی" به نمایش درآمده است. او بدون محاکمه به اردوگاه گوانتانامو منتقل شد و به مدت ۱۵ سال تحت شکنجه قرار گرفت. این اتفاق پس از یک تماس تلفنی با یکی از بستگانش در افغانستان رخ داد. او به ظن ارتباط با حملات ۱۱ سپتامبر، بدون محاکمه به اردوگاه گوانتانامو منتقل شد.
 </p>
 <p>
-    افراد عادی به خاطر آنچه که به‌صورت آنلاین به اشتراک می‌گذارند، حتی از طریق حساب‌های 'ناشناس' خود، <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html" target="_blank">حتی در کشورهای دموکراتیک</a> دستگیر می‌شوند.
+    افراد عادی به خاطر آنچه که به‌صورت آنلاین به اشتراک می‌گذارند، حتی از طریق حساب‌های 'ناشناس' خود، <a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html' target='_blank'>حتی در کشورهای دموکراتیک</a> دستگیر می‌شوند.
 </p>
 <p>
-    استفاده از یک پیام‌رسان رمزنگاری شده انتها به انتها کافی نیست؛ همه ما باید از پیام‌رسان‌هایی استفاده کنیم که حریم خصوصی شبکه‌های شخصی ما را محافظت می‌کنند — اینکه با چه کسانی ارتباط داریم.
+    استفاده از یک پیام‌رسان رمزنگاری شده انتها به انتها کافی نیست؛ همه ما باید از پیام‌رسان‌هایی استفاده کنیم که حریم خصوصی شبکه‌های شخصی ما را محافظت می‌کنند &mdash; اینکه با چه کسانی ارتباط داریم.
 </p>
 
                         </div>
@@ -1056,7 +1061,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1074,7 +1079,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">چرا SimpleX <span class="gradient-text">منحصربه‌فرد</span> است</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">چرا SimpleX <span class='gradient-text'>منحصربه‌فرد</span> است</h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1089,7 +1094,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما حریم خصوصی کاملی دارید</h3>
                             </div>
 
@@ -1100,7 +1105,7 @@ window.addEventListener('click',(e)=>{
     SimpleX حریم خصوصی پروفایل، مخاطبین و فراداده‌های شما را محافظت می‌کند و آن‌ها را از سرورهای شبکه SimpleX و هر ناظر دیگری پنهان می‌سازد.
 </p>
 <p>
-    برخلاف هر شبکه پیام‌رسان دیگری، SimpleX هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد — <strong>حتی شماره‌های تصادفی</strong> نیز وجود ندارد.
+    برخلاف هر شبکه پیام‌رسان دیگری، SimpleX هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد &mdash; <strong>حتی شماره‌های تصادفی</strong> نیز وجود ندارد.
 </p>
 
                                     </div>
@@ -1116,7 +1121,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">اطلاعات بیشتر</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1124,7 +1129,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">پنهان کردن اطلاعات</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1140,7 +1145,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما از هرزنامه و سوءاستفاده محافظت می‌شوید</h3>
                             </div>
 
@@ -1164,7 +1169,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">اطلاعات بیشتر</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1172,7 +1177,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">پنهان کردن اطلاعات</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1188,7 +1193,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">شما بر داده‌های خود کنترل دارید</h3>
                             </div>
 
@@ -1196,7 +1201,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleX تمام داده‌های کاربری را بر روی دستگاه‌های کلاینت در یک <strong>فرمت پایگاه داده رمزنگاری شده قابل حمل</strong> ذخیره می‌کند — این داده‌ها می‌توانند به دستگاه دیگری منتقل شوند.
+    SimpleX تمام داده‌های کاربری را بر روی دستگاه‌های کلاینت در یک <strong>فرمت پایگاه داده رمزنگاری شده قابل حمل</strong> ذخیره می‌کند &mdash; این داده‌ها می‌توانند به دستگاه دیگری منتقل شوند.
 </p>
 <p>
     پیام‌های رمزنگاری شده انتها به انتها به‌طور موقت بر روی سرورهای رله SimpleX نگهداری می‌شوند تا دریافت شوند و سپس به‌طور دائمی حذف می‌شوند.
@@ -1215,7 +1220,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">اطلاعات بیشتر</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1223,7 +1228,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">پنهان کردن اطلاعات</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1239,7 +1244,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">­شما مالک شبکه SimpleX هستید</h3>
                             </div>
 
@@ -1250,7 +1255,7 @@ window.addEventListener('click',(e)=>{
     شبکه SimpleX به‌طور کامل غیرمتمرکز و مستقل از هر ارز دیجیتال یا هر شبکه دیگری به جز اینترنت است.
 </p>
 <p>
-    شما می‌توانید <strong>از SimpleX با سرورهای خود استفاده کنید</strong> یا از سرورهای ارائه‌شده توسط ما استفاده کنید — و همچنان به هر کاربری متصل شوید.
+    شما می‌توانید <strong>از SimpleX با سرورهای خود استفاده کنید</strong> یا از سرورهای ارائه‌شده توسط ما استفاده کنید &mdash; و همچنان به هر کاربری متصل شوید.
 </p>
 
                                     </div>
@@ -1266,7 +1271,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">اطلاعات بیشتر</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1274,7 +1279,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">پنهان کردن اطلاعات</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1311,10 +1316,10 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    برخلاف سایر شبکه‌های پیام‌رسان، SimpleX <strong>هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد</strong>. این شبکه به شماره‌های تلفن، آدرس‌های مبتنی بر دامنه (مانند ایمیل یا XMPP)، نام‌های کاربری، کلیدهای عمومی یا حتی شماره‌های تصادفی برای شناسایی کاربران خود تکیه نمی‌کند — اپراتورهای سرور SimpleX نمی‌دانند چند نفر از سرورهای آن‌ها استفاده می‌کنند.
+    برخلاف سایر شبکه‌های پیام‌رسان، SimpleX <strong>هیچ شناسه‌ای به کاربران اختصاص نمی‌دهد</strong>. این شبکه به شماره‌های تلفن، آدرس‌های مبتنی بر دامنه (مانند ایمیل یا XMPP)، نام‌های کاربری، کلیدهای عمومی یا حتی شماره‌های تصادفی برای شناسایی کاربران خود تکیه نمی‌کند &mdash; اپراتورهای سرور SimpleX نمی‌دانند چند نفر از سرورهای آن‌ها استفاده می‌کنند.
 </p>
 <p>
-    برای ارسال پیام‌ها، SimpleX از <a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">آدرس‌های ناشناس جفتی</a> در صف‌های پیام یک‌طرفه استفاده می‌کند که برای پیام‌های دریافتی و ارسال‌شده جداگانه هستند و معمولاً از طریق سرورهای مختلف انجام می‌شود.
+    برای ارسال پیام‌ها، SimpleX از <a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>آدرس‌های ناشناس جفتی</a> در صف‌های پیام یک‌طرفه استفاده می‌کند که برای پیام‌های دریافتی و ارسال‌شده جداگانه هستند و معمولاً از طریق سرورهای مختلف انجام می‌شود.
 </p>
 <p>
     این طراحی از حریم خصوصی افرادی را که با آن‌ها ارتباط دارید، محافظت می‌کند و آن را از سرورهای شبکه SimpleX و هر ناظر دیگری پنهان می‌سازد. برای پنهان کردن آدرس IP خود از سرورها، می‌توانید <strong>از طریق Tor به سرورهای SimpleX متصل شوید</strong>.
@@ -1335,7 +1340,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1374,7 +1379,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1401,7 +1406,7 @@ window.addEventListener('click',(e)=>{
     برخلاف سرورهای شبکه‌های فدرال (ایمیل، XMPP یا Matrix)، سرورهای SimpleX حساب‌های کاربری را ذخیره نمی‌کنند و تنها پیام‌ها را منتقل می‌کنند، که حریم خصوصی هر دو طرف را محافظت می‌کند.
 </p>
 <p>
-    هیچ شناسه یا متن رمز مشترکی بین ترافیک سرور ارسال‌شده و دریافتی وجود ندارد — اگر کسی در حال نظارت باشد، نمی‌تواند به‌راحتی تشخیص دهد که چه کسی با چه کسی ارتباط برقرار می‌کند، حتی اگر TLS به خطر بیفتد.
+    هیچ شناسه یا متن رمز مشترکی بین ترافیک سرور ارسال‌شده و دریافتی وجود ندارد &mdash; اگر کسی در حال نظارت باشد، نمی‌تواند به‌راحتی تشخیص دهد که چه کسی با چه کسی ارتباط برقرار می‌کند، حتی اگر TLS به خطر بیفتد.
 </p>
 
                         </div>
@@ -1419,7 +1424,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,10 +1445,10 @@ window.addEventListener('click',(e)=>{
     شما می‌توانید <strong>از SimpleX با سرورهای خود استفاده کنید</strong> و همچنان با افرادی که از سرورهای پیش‌پیکربندی‌شده در برنامه‌ها استفاده می‌کنند، ارتباط برقرار کنید.
 </p>
 <p>
-    شبکه SimpleX از یک <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">پروتکل باز</a> استفاده می‌کند و <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK برای ایجاد ربات‌های چت</a> ارائه می‌دهد، که امکان پیاده‌سازی خدماتی را فراهم می‌کند که کاربران می‌توانند از طریق برنامه‌های چت SimpleX با آن‌ها تعامل داشته باشند — ما واقعاً منتظر هستیم ببینیم چه خدماتی را با SimpleX ایجاد خواهید کرد.
+    شبکه SimpleX از یک <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>پروتکل باز</a> استفاده می‌کند و <a href='https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript' target='_blank'>SDK برای ایجاد ربات‌های چت</a> ارائه می‌دهد، که امکان پیاده‌سازی خدماتی را فراهم می‌کند که کاربران می‌توانند از طریق برنامه‌های چت SimpleX با آن‌ها تعامل داشته باشند &mdash; ما واقعاً منتظر هستیم ببینیم چه خدماتی را با SimpleX ایجاد خواهید کرد.
 </p>
 <p>
-    اگر به توسعه برای شبکه SimpleX فکر می‌کنید، مثلاً ربات چت برای کاربران برنامه SimpleX یا ادغام کتابخانه چت SimpleX در برنامه‌های موبایل خود، لطفاً برای هرگونه مشاوره و پشتیبانی <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">با ما تماس بگیرید</a>.
+    اگر به توسعه برای شبکه SimpleX فکر می‌کنید، مثلاً ربات چت برای کاربران برنامه SimpleX یا ادغام کتابخانه چت SimpleX در برنامه‌های موبایل خود، لطفاً برای هرگونه مشاوره و پشتیبانی <a href='https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>با ما تماس بگیرید</a>.
 </p>
 
                         </div>
@@ -1461,7 +1466,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1492,66 +1497,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">پیام‌های رمزنگاری شده انتها به انتها با ویرایش و فرمت‌بندی Markdown</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">تصاویر، ویدیوها و فایل‌های رمزنگاری شده انتها به انتها<br></p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">گروه‌های غیرمتمرکز رمزنگاری شده انتها به انتها — تنها کاربران می‌دانند که این گروه‎ها وجود دارند</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">گروه‌های غیرمتمرکز رمزنگاری شده انتها به انتها &mdash; تنها کاربران می‌دانند که این گروه‎ها وجود دارند</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">پیام‌های صوتی رمزنگاری شده به صورت انتها به انتها</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">پیام‌های ناپدید شونده</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">تماس‌های صوتی و ویدیویی رمزنگاری شده انتها به انتها<br></p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">فضای ذخیره‌سازی رمزنگاری شده قابل حمل — انتقال پروفایل به دستگاه دیگر</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">فضای ذخیره‌سازی رمزنگاری شده قابل حمل &mdash; انتقال پروفایل به دستگاه دیگر</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">حالت ناشناس —<br>منحصربه‌فرد برای SimpleX Chat</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">حالت ناشناس &mdash;<br>منحصربه‌فرد برای SimpleX Chat</p>
             </div>
             
         </div>
@@ -1561,7 +1566,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">چه چیزی SimpleX را <span class="gradient-text">خصوصی</span> می‌کند</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">چه چیزی SimpleX را <span class='gradient-text'>خصوصی</span> می‌کند</h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1569,8 +1574,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">شناسه‌های موقت ناشناس دوطرفه</h3>
@@ -1587,8 +1592,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">مبادله کلید خارج از باند<br></h3>
@@ -1605,8 +1610,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">دو لایه از<br>رمزنگاری انتها به انتها</h3>
@@ -1623,8 +1628,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">تأیید صحت پیام<br></h3>
@@ -1641,8 +1646,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">لایه اضافی از<br>رمزنگاری سرور</h3>
@@ -1657,8 +1662,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">مخلوط‌سازی پیام<br>برای کاهش امکان رهگیری</h3>
@@ -1673,8 +1678,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">انتقال TLS امن و تأییدشده<br></h3>
@@ -1693,8 +1698,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">دسترسی اختیاری از طریق<br>Tor</h3>
@@ -1711,8 +1716,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">صف‌های پیام یک‌طرفه<br></h3>
@@ -1729,8 +1734,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">چندین لایه از<br>پدینگ محتوا</h3>
@@ -1765,14 +1770,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">شبکه <span class="gradient-text">SimpleX</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">شبکه <span class='gradient-text'>SimpleX</span></h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">چت SimpleX بهترین حریم خصوصی را با ترکیب مزایای شبکه‌های P2P و شبکه‌های فدرال ارائه می‌دهد.</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">برخلاف شبکه‌های P2P</h3>
@@ -1780,7 +1785,7 @@ window.addEventListener('click',(e)=>{
                         تمام پیام‌ها از طریق سرورها ارسال می‌شوند که هم حریم خصوصی فراداده را بهتر تأمین می‌کند و هم تحویل پیام‌های غیرهمزمان قابل اعتماد را فراهم می‌آورد، در حالی که از بسیاری از مشکلات جلوگیری می‌کند. <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">مشکلات شبکه‌های P2P</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">مقایسه با پروتکل‌های پیام‌رسانی P2P</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1788,26 +1793,26 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    پروتکل‌ها و برنامه‌های پیام‌رسانی <a href="https://en.wikipedia.org/wiki/Peer-to-peer">P2P</a> مشکلات متعددی دارند که آن‌ها را نسبت به SimpleX کمتر قابل اعتماد، تحلیل آن‌ها را پیچیده‌تر و در برابر چندین نوع حمله آسیب‌پذیر می‌کند.
+    پروتکل‌ها و برنامه‌های پیام‌رسانی <a href='https://en.wikipedia.org/wiki/Peer-to-peer'>P2P</a> مشکلات متعددی دارند که آن‌ها را نسبت به SimpleX کمتر قابل اعتماد، تحلیل آن‌ها را پیچیده‌تر و در برابر چندین نوع حمله آسیب‌پذیر می‌کند.
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
-        شبکه‌های P2P به نوعی از <a href="https://en.wikipedia.org/wiki/Distributed_hash_table">DHT</a> برای مسیریابی پیام‌ها وابسته هستند. طراحی‌های DHT باید بین تضمین تحویل و تأخیر تعادل برقرار کنند. SimpleX هم تضمین تحویل بهتری دارد و هم تأخیر کمتری نسبت به P2P، زیرا پیام می‌تواند به صورت اضافی از طریق چندین سرور به طور موازی منتقل شود و از سرورهای انتخاب‌شده توسط گیرنده استفاده کند. در شبکه‌های P2P، پیام به صورت ترتیبی از طریق <em>O(log N)</em> گره منتقل می‌شود و این گره‌ها توسط الگوریتم انتخاب می‌شوند.
+        شبکه‌های P2P به نوعی از <a href='https://en.wikipedia.org/wiki/Distributed_hash_table'>DHT</a> برای مسیریابی پیام‌ها وابسته هستند. طراحی‌های DHT باید بین تضمین تحویل و تأخیر تعادل برقرار کنند. SimpleX هم تضمین تحویل بهتری دارد و هم تأخیر کمتری نسبت به P2P، زیرا پیام می‌تواند به صورت اضافی از طریق چندین سرور به طور موازی منتقل شود و از سرورهای انتخاب‌شده توسط گیرنده استفاده کند. در شبکه‌های P2P، پیام به صورت ترتیبی از طریق <em>O(log N)</em> گره منتقل می‌شود و این گره‌ها توسط الگوریتم انتخاب می‌شوند.
     </li>
     <li>
         طراحی SimpleX، برخلاف اکثر شبکه‌های P2P، هیچ شناسه کاربری جهانی از هیچ نوعی، حتی موقتی، ندارد و فقط از شناسه‌های جفت‌به‌جفت موقتی استفاده می‌کند که این امر حریم خصوصی و محافظت از فراداده را بهتر فراهم می‌کند.
     </li>
     <li>
-        P2P مشکل <a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">حملات MITM</a> را حل نمی‌کند و بیشتر پیاده‌سازی‌های موجود از پیام‌های خارج از باند برای تبادل کلید اولیه استفاده نمی‌کنند. SimpleX از پیام‌های خارج از باند یا در برخی موارد، از اتصالات امن و مورد اعتماد پیشین برای تبادل کلید اولیه استفاده می‌کند.
+        P2P مشکل <a href='https://en.wikipedia.org/wiki/Man-in-the-middle_attack'>حملات MITM</a> را حل نمی‌کند و بیشتر پیاده‌سازی‌های موجود از پیام‌های خارج از باند برای تبادل کلید اولیه استفاده نمی‌کنند. SimpleX از پیام‌های خارج از باند یا در برخی موارد، از اتصالات امن و مورد اعتماد پیشین برای تبادل کلید اولیه استفاده می‌کند.
     </li>
     <li>
-        پیاده‌سازی‌های P2P می‌توانند توسط برخی از ارائه‌دهندگان اینترنت (مانند <a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a>) مسدود شوند. SimpleX مستقل از نوع حمل و نقل است — این امکان را دارد که بر روی پروتکل‌های وب استاندارد، مانند WebSockets، کار کند.
+        پیاده‌سازی‌های P2P می‌توانند توسط برخی از ارائه‌دهندگان اینترنت (مانند <a href='https://en.wikipedia.org/wiki/BitTorrent'>BitTorrent</a>) مسدود شوند. SimpleX مستقل از نوع حمل و نقل است — این امکان را دارد که بر روی پروتکل‌های وب استاندارد، مانند WebSockets، کار کند.
     </li>
     <li>
-        تمام شبکه‌های P2P شناخته‌شده ممکن است در معرض <a href="https://en.wikipedia.org/wiki/Sybil_attack">حمله Sybil </a> قرار بگیرند، زیرا هر گره قابل شناسایی است و شبکه به‌عنوان یک کل عمل می‌کند. تدابیر شناخته‌شده برای کاهش آن نیاز به یک مؤلفه متمرکز یا <a href="https://en.wikipedia.org/wiki/Proof_of_work">اثبات کار</a> پرهزینه دارند. شبکه SimpleX هیچ کشف‌پذیری سروری ندارد، تکه‌تکه است و به‌عنوان چندین زیرشبکه ایزوله عمل می‌کند، که حملات در سطح شبکه را غیرممکن می‌سازد.
+        تمام شبکه‌های P2P شناخته‌شده ممکن است در معرض <a href='https://en.wikipedia.org/wiki/Sybil_attack'>حمله Sybil </a> قرار بگیرند، زیرا هر گره قابل شناسایی است و شبکه به‌عنوان یک کل عمل می‌کند. تدابیر شناخته‌شده برای کاهش آن نیاز به یک مؤلفه متمرکز یا <a href='https://en.wikipedia.org/wiki/Proof_of_work'>اثبات کار</a> پرهزینه دارند. شبکه SimpleX هیچ کشف‌پذیری سروری ندارد، تکه‌تکه است و به‌عنوان چندین زیرشبکه ایزوله عمل می‌کند، که حملات در سطح شبکه را غیرممکن می‌سازد.
     </li>
     <li>
-        شبکه‌های P2P ممکن است در معرض <a href="https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent">حمله DRDoS</a> قرار بگیرند، زمانی که کلاینت‌ها می‌توانند ترافیک را دوباره پخش و تقویت کنند که منجر به عدم دسترسی به خدمات در سطح شبکه می‌شود. کلاینت‌های SimpleX تنها ترافیک را از اتصالات شناخته‌شده منتقل می‌کنند و نمی‌توانند توسط یک مهاجم برای تقویت ترافیک در کل شبکه استفاده شوند.
+        شبکه‌های P2P ممکن است در معرض <a href='https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent'>حمله DRDoS</a> قرار بگیرند، زمانی که کلاینت‌ها می‌توانند ترافیک را دوباره پخش و تقویت کنند که منجر به عدم دسترسی به خدمات در سطح شبکه می‌شود. کلاینت‌های SimpleX تنها ترافیک را از اتصالات شناخته‌شده منتقل می‌کنند و نمی‌توانند توسط یک مهاجم برای تقویت ترافیک در کل شبکه استفاده شوند.
     </li>
 </ol>
                         </div>
@@ -1825,12 +1830,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1838,8 +1843,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">برخلاف شبکه‌های فدرال</h3>
@@ -1853,13 +1858,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">شبکه SimpleX</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        سرورها <span class="text-active-blue">صف‌های یک‌طرفه</span> را برای اتصال کاربران فراهم می‌کنند، اما هیچ دیدگاهی از نمودار ارتباطات شبکه ندارند — تنها کاربران این دید را دارند.
+                        سرورها <span class='text-active-blue'>صف‌های یک‌طرفه</span> را برای اتصال کاربران فراهم می‌کنند، اما هیچ دیدگاهی از نمودار ارتباطات شبکه ندارند &mdash; تنها کاربران این دید را دارند.
                     </p>
                 </div>
             </div>
@@ -1916,7 +1921,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">۱. تجربه کاربران</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             شما می‌توانید مخاطبین و گروه‌ها را ایجاد کنید و مانند هر پیام‌رسان دیگری، مکالمات دوطرفه داشته باشید.
                         </p>
@@ -1929,7 +1934,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">۲. چگونه کار می‌کند</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             برای هر اتصال، شما از دو صف پیام جداگانه برای ارسال و دریافت پیام‌ها از طریق سرورهای مختلف استفاده می‌کنید.
                         </p>
@@ -1942,7 +1947,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">۳. آنچه سرورها می‌بینند</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             سرورها برای هر صف دارای اعتبارنامه‌های جداگانه و ناشناس هستند و نمی‌دانند که این اعتبارنامه‌ها به کدام کاربران تعلق دارند.
                         </p>
@@ -2043,8 +2048,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">سیگنال، پلتفرم‌های بزرگ</th>
                         <th class="pb-4">XMPP، Matrix</th>
@@ -2102,7 +2107,7 @@ window.addEventListener("load", function () {
                     <li> رله‌های SimpleX نمی‌توانند رمزنگاری انتها به انتها را به خطر بیندازند. توصیه می‌شود کد امنیتی را برای کاهش حمله در کانال out-of-band تأیید کنید</li>
                     <li> اگر سرورهای اپراتور به خطر بیفتند. کد امنیتی را در سیگنال و برخی دیگر از برنامه‌ها تأیید کنید تا این خطر را کاهش دهید</li>
                     <li> از حریم خصوصی فراداده‌های کاربران محافظت نمی‌کند</li>
-                    <li> در حالی که شبکه‌های P2P توزیع‌شده هستند، اما فدرال نیستند — آن‌ها به‌عنوان یک شبکه واحد عمل می‌کنند</li>
+                    <li> در حالی که شبکه‌های P2P توزیع‌شده هستند، اما فدرال نیستند &mdash; آن‌ها به‌عنوان یک شبکه واحد عمل می‌کنند</li>
                     <li> شبکه‌های P2P یا دارای یک نهاد مرکزی هستند یا کل شبکه می‌تواند به خطر بیفتد - <a class="underline text-primary-light dark:text-primary-dark underline-offset-2" href="https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols">اینجا را ببینید</a></li>
                 </ol>
             </div>
@@ -2127,10 +2132,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">برای دریافت به‌روزرسانی‌های ما ثبت‌نام کنید</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="آدرس ایمیل خود را وارد کنید">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2139,28 +2146,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">برنامه <a href="/downloads">دسکتاپ SimpleX</a> را دریافت کنید</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fa/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fa/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fa/why.md b/fa/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/fa/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/fa/why/index.html b/fa/why/index.html
index 13d802e4c2..d064487799 100644
--- a/fa/why/index.html
+++ b/fa/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fa/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/faq.md b/faq.md
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+# Frequently Asked Questions
+
+[How to use it](#how-to-use-it)
+- [How do I connect to people?](#how-do-i-connect-to-people)
+- [I have nobody to chat with! Where can I find any groups?](#i-have-nobody-to-chat-with-where-can-i-find-any-groups)
+- [What is database? What can I do with it?](#what-is-database-what-can-i-do-with-it)
+- [Can I send files over SimpleX? ](#can-i-send-files-over-simplex)
+- [What’s incognito profile?](#whats-incognito-profile)
+- [How do invitations work?](#how-do-invitations-work)
+- [How to configure and delete groups?](#how-to-configure-and-delete-groups)
+- [Are there any reactions to messages? Can I answer specific messages directly?](#are-there-any-reactions-to-messages-can-i-answer-specific-messages-directly)
+- [What do checkmarks mean?](#what-do-checkmarks-mean)
+- [I want to see when my contacts read my messages](#i-want-to-see-when-my-contacts-read-my-messages)
+- [Can I use the same profile on desktop? Do messages sync cross-platform?](#can-i-use-the-same-profile-on-desktop-do-messages-sync-cross-platform)
+- [Why cannot I delete messages I sent from my contact's device?](#why-cannot-i-delete-messages-i-sent-from-my-contacts-device)
+- [What do group roles mean?](#what-do-group-roles-mean)
+- [I don't want to share a web link or a QR code. How can I connect?](#i-dont-want-to-share-a-web-link-or-a-qr-code-how-can-i-connect)
+- [How to change servers to my own](#how-to-change-servers-to-my-own)
+
+[Troubleshooting](#troubleshooting)
+- [I do not receive messages or message notifications](#i-do-not-receive-messages-or-message-notifications)
+- [I do not see the second tick on the messages I sent](#i-do-not-see-the-second-tick-on-the-messages-i-sent)
+- [I see image preview but cannot open the image](#i-see-image-preview-but-cannot-open-the-image)
+- [I cannot play a voice message](#i-cannot-play-a-voice-message)
+- [Audio or video calls do not connect](#audio-or-video-calls-do-not-connect)
+- [Audio or video calls without e2e encryption](#audio-or-video-calls-without-e2e-encryption)
+- [I clicked the link to connect, but could not connect](#i-clicked-the-link-to-connect-but-could-not-connect)
+- [I do not know my database passphrase](#i-do-not-know-my-database-passphrase)
+- [My mobile app does not connect to desktop app](#my-mobile-app-does-not-connect-to-desktop-app)
+
+[Privacy and security](#privacy-and-security)
+- [Does SimpleX support post quantum cryptography?](#does-simplex-support-post-quantum-cryptography)
+- [Why can't I use the same profile on different devices?](#why-cant-i-use-the-same-profile-on-different-devices)
+- [What user data can be provided on request?](#what-user-data-can-be-provided-on-request)
+- [Does SimpleX protect my IP address?](#does-simplex-protect-my-ip-address)
+- [Doesn't private message routing reinvent Tor?](#doesnt-private-message-routing-reinvent-tor)
+- [Why don't you embed Tor in SimpleX Chat app?](#why-dont-you-embed-tor-in-simplex-chat-app)
+- [Can I host my own relays?](#can-i-host-my-own-relays)
+
+[Funding and business model](#funding-and-business-model)
+- [How are you funded?](#how-are-you-funded)
+- [Why VCs?](#why-vcs)
+- [What will be the business model?](#what-will-be-the-business-model)
+
+## How to use it
+
+### How do I connect to people?
+
+Tap "pencil" button in the right corner, then "Create 1-time link". Share the link with the person you want to connect to. Your contact has to paste the link to the app's search bar. The link can also be opened via the browser, once the app is installed.
+
+Alternatively, you can show the QR code when meeting in person or in a video call.
+
+It is safe to share this link over any communication channel, it contains only public keys and can only be used once.
+
+If you want to share your address publicly, so that many people can connect to you, use your SimpleX address instead of 1-time links. Tap your profile image/avatar, then Your SimpleX address. Once you create the address, you can share it in social media profiles, email signature, etc. See [the comparison of SimpleX address with 1-time links](https://simplex.chat/docs/guide/making-connections.md#comparison-of-1-time-invitation-links-and-simplex-contact-addresses).
+
+### I have nobody to chat with! Where can I find any groups?
+
+Please check our [Groups Directory](https://simplex.chat/docs/directory.md) in the first place. You might find some interesting groups and meet even more interesting people.
+
+### What is database? What can I do with it?
+
+Database is essential for SimpleX Chat to function properly. In comparison to centralized messaging providers, it is _the user_ who is responsible for taking care of their data. On the other hand, user is sure that _nobody but them_ has access to it. Please read more about it: [Database](https://simplex.chat/docs/guide/managing-data.md).
+
+### Can I send files over SimpleX?
+
+Of course! While doing so, you are using a _state-of-the-art_ protocol that greatly reduces metadata leaks. Please read more about it: [XFTP Protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md).
+
+### What’s incognito profile?
+
+This feature is unique to SimpleX Chat – it is independent from chat profiles.
+
+When "Incognito Mode” is turned on, your currently chosen profile name and image are hidden from your new contacts. It allows anonymous connections with other people without any shared data – when you make new connections or join groups via a link a new random profile name will be generated for each connection.
+
+### How do invitations work?
+
+It is quite a complex process, but fortunately all of this happens in the background, so it's simple to use.
+
+Whenever somebody connects to you via your address, they basically ask your client whether they want to establish connection. After that, you can either agree or disagree.
+If interested, please read more: [Addresses and invitations](https://simplex.chat/docs/guide/making-connections.md).
+
+### How to configure and delete groups?
+
+Please check: [Users guide](https://simplex.chat/docs/guide/secret-groups.md).
+
+### Are there any reactions to messages? Can I answer specific messages directly?
+
+Yes! Currently, there are six emojis available. What's more, you can respond to specific message by holding it and selecting _Reply_.
+
+### What do checkmarks mean?
+
+It's quite simple:
+- one checkmark - message is delivered to the relay (the server).
+- two checkmarks - message is delivered to the recipient's device.
+"sent" means accepted by the relay for delivery, "delivered" - stored on the recipient device.
+
+Also see: [I do not see the second tick on the messages I sent](#i-do-not-see-the-second-tick-on-the-messages-i-sent)
+
+### I want to see when my contacts read my messages
+
+To know when your contact reads your messages, your contact's app has to send you a confirmation message. And vice versa, for your contact to know when you read the message, your app has to send a confirmation message.
+
+The important questions for this feature:
+- do you always want that your contacts can see when you read all their messages? Probably, even with your close friends, sometimes you would prefer to have time before you answer their message, and also have a plausible deniability that you have not seen the message. And this should be ok - in the end, this is your device, and it should be for you to decide whether this confirmation message is sent or not, and when it is sent.
+- what practical problems an automatic notification sent to your contacts when you read the message solves for you compared with you simply adding a reaction to a message or sending a quick reply?
+
+Overall, it seems that this feature is more damaging to your communications with your contacts than it is helpful. It keeps senders longer in the app, nervously waiting for read receipts, exploiting addictive patterns - having you spend more time in the app is the reason why it is usually present in most messaging apps. It also creates a pressure on the recipients to reply sooner, and if read receipts are opt-in, it creates a pressure to enable it, that can be particularly damaging in any relationships with power imbalance.
+
+We think that delivery receipts are important and equally benefit both sides as the conversation, as they confirm that communication network functions properly. But we strongly believe that read receipts are an anti-feature that only benefits the app developers, and hurts the relations between the app users. So we are not planning to add it even as opt-in. In case you want your contact to know you've read the message put a reaction to it. And if you don't want them to know it - it is also ok, what your device sends should be under your control.
+
+### Can I use the same profile on desktop? Do messages sync cross-platform?
+
+You can use your profile from mobile device on desktop. However, to do so you need to be on the same network, both on your mobile and desktop. More about it: [Release info](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol).
+
+### Why cannot I delete messages I sent from my contact's device?
+
+In SimpleX Chat, you and your contacts can delete the messages you send from recipients' devices if you both agree to that within 24 hours of sending it. To be able to do that you both have to enable "Delete for everyone" option in Contact preferences - tap on the contact's name above the conversation to get there.
+
+You can also revoke the files you send. If the recipients did not yet receive the file, they will not be able to receive it after the file is revoked.
+
+This is different from most other messengers that allow deleting messages from the recipients' devices without any agreement with the recipients.
+
+We believe that allowing deleting information from your device to your contacts is a very wrong design decision for several reasons:
+1) it violates your data sovereignty as the device owner - once you are in possession of any information, you have the rights to retain it, and any deletion should be agreed with you. And security and privacy is not possible if users don't have sovereignty over their devices.
+2) it may be a business communication, and either your organization policy or a compliance requirement is that every message you receive must be preserved for some time.
+3) the message can contain a legally binding promise, effectively a contract between you and your contact, in which case you both need to keep it.
+4) the messages may contain threat or abuse and you may want to keep them as a proof.
+5) you may have paid for the message (e.g., it can be a design project or consulting report), and you don't want it to suddenly disappear before you had a chance to store it outside of the conversation.
+
+It is also important to remember, that even if your contact enabled "Delete for everyone", you cannot really see it as a strong guarantee that the message will be deleted. Your contact's app can have a very simple modification (a one-line code change), that would prevent this deletion from happening when you request it. So you cannot see it as something that guarantees your security from your contacts.
+
+When "Delete for everyone" is not enabled, you can still mark the sent message as deleted within 24 hours of sending it. In this case the recipient will see it as "deleted message", and will be able to reveal the original message.
+
+### What do group roles mean?
+
+Groups support 5 member roles: owner, admin, moderator, member and observer.
+
+An observer can:
+- add reactions
+- send reports
+- talk to admins via "Chat with admins"
+
+A member can:
+- send messages
+
+A moderator can:
+- approve members in review ("knocking")
+- moderate messages<sup>*</sup>
+- block members temporarily<sup>*</sup>
+- participate in "Chats with members"
+
+An admin can:
+- add and remove members<sup>*</sup>
+- change member roles<sup>*</sup>, including their own
+- create group links (but the new members will join via them, so use links of admins who are always online).
+
+A group owner can:
+- edit group profile
+- delete the group
+
+Each role can do everything that the previous roles can, except moderators and higher cannot send reports or "Chat with admins".
+
+<sup>*</sup>Any actions affecting members or their messages can only be applied to members of the same or lower role (so admins can't demote owners or promote anybody to owners, etc., but they can demote other admins and themselves, or make anybody an admin).
+
+### I don't want to share a web link or a QR code. How can I connect?
+
+You can replace the server part of the link (e.g., `https://smp18.simplex.im/`) with `simplex:/` and add `?h=smp18.simplex.im` (replace it with server of your link) to the end of the link. Then it will not be possible to use it in a web browser, but it will be recognized by SimpleX Chat app.
+
+For example, this link: `https://smp18.simplex.im/i#E74vSxMwDnEx6DAvRCZmzBeZwwAseJUD/yVTHjaaH_EzL19DG7fvd46Mjry3IBqYT0UMo5G7l4jQ`
+
+becomes: `simplex:/i#E74vSxMwDnEx6DAvRCZmzBeZwwAseJUD/yVTHjaaH_EzL19DG7fvd46Mjry3IBqYT0UMo5G7l4jQ?h=smp18.simplex.im`
+
+### How to change servers to my own?
+
+Add your server in Settings -> Network & servers -> Your servers. If you have multiple profiles, you need to add your server in every profile.
+After that, disable all preset servers. If you have multiple profiles, you must first add your server to all profiles for this option to be available.
+
+To resolve SimpleX public names, if your server does not support it, you may leave preset servers enabled only for resolving the public names.
+
+Please note: configured servers only determine which servers will be used for the new connections (members/contacts). Previously created connections don't switch automatically. You can manually switch all existing contacts and small/important groups (each member needs to be switched), and then leave and re-join all large groups.
+You can switch contacts/members manually to another server by going to their profile and clicking on "Change receiving address", note that the current server must be online for the address change to work.
+
+## Troubleshooting
+
+### I do not receive messages or message notifications
+
+There may be several reasons messages are not delivered to you from your contact:
+
+**You or your contact cannot connect to the server that you use to receive messages from your contact.**
+
+You can check which server is used to receive messages by tapping the contact name above the conversation.
+
+You can also run tests for this server from the app Network settings.
+
+Please ask your contact if they have a single tick on the message to determine if the message failed to send or if you fail to receive it.
+
+**Message delivery got stuck because of some unresolved bug.**
+
+Fully restarting the app is the workaround to resume message delivery.
+
+To do it on iOS, simply close the app (swipe up from the opened apps) and open it again.
+
+To do it on Android - choose Restart from the app settings, simply closing and re-opening the app will not restart the messaging service.
+
+**Your Android operating system kills the app while it is in background.**
+
+Check battery settings for the app - it should be set to Unrestricted.
+
+For some devices, there may be additional options to prevent the app from being killed - e.g., on Xiaomi you need to enable Auto Start setting for the app. Please consult https://dontkillmyapp.com site for any additional settings for your device.
+
+**Why my notifications aren't working on iOS**
+
+Check the color of the bolt icon next to Notifications in app settings - it should be green.
+
+If it's not, please open notifications, disable them (choose Off / Local), and then enable again - you should do it when you have Internet connection.
+
+Check if your push server has been restarted at time of the issue (Notifications -> Push server) at https://status.simplex.chat if it has been restarted, you may not receive notifications from that time.
+
+If device was offline, you may need to open the app to start receiving notifications.
+
+If the above didn't help, the reason could be that iOS failed to issue notification token - we have seen this issue several times. In this case, restarting the whole device should help.
+
+In some cases notifications may still not work, iOS notifications are hard to do right in a decentralized app, we will be improving them soon to be more reliable.
+
+**Messaging server or notification server is under maintenance**
+
+Please check the current status of preset servers at [https://status.simplex.chat](https://status.simplex.chat). You can also connect to status bot via QR code on that page - it will send the updates when the server is offline for maintenance, and also when the new versions of the app are released.
+
+### I do not see the second tick on the messages I sent
+
+You may not have the second tick on your sent messages for these reasons:
+
+- your contact is not online, and did not receive your message.
+- possibly, message delivery to your contact or to you is disrupted - see [I do not receive messages](#i-do-not-receive-messages-or-message-notifications) - please check with your contact via some other channel if they received your message. If the message was delivered, then it means your device could fail to receive the delivery notification.
+- possibly, your contact disabled sending delivery receipts - it can be disabled for specific or for all contacts - please check with your contact.
+
+### I see image preview but cannot open the image
+
+It can be for these reasons:
+- your contact did not finish uploading the image file, possibly closing the app too quickly. When the image file is fully uploaded there will be a tick in the _top right corner_ of the image.
+- your device fails to receive it. Please check server connectivity and run server tests, and also try increasing network timeouts in Advanced network settings. File reception was substantially improved in v5.7 - please make sure you are using the latest version.
+- file expired and can no longer be received. Files can be received only for 2 days after they were sent, after that they won't be available and will show X in the top right corner.
+
+### I cannot play a voice message
+
+This can happen for similar reasons as for [images](#i-see-image-preview-but-cannot-open-the-image).
+
+Please check your network settings and make sure you use the latest version of the app.
+
+Please report such issues if you use v5.7 or newer.
+
+### Audio or video calls do not connect
+
+App uses WebRTC for calls. Please check that you can connect to the servers configured in the app: stun.simplex.im and turn.simplex.im - see [troubleshooting WebRTC](https://simplex.chat/docs/webrtc.md#troubleshoot).
+
+If you can connect to the server, please report this issue to us privately, including the following information:
+
+- how you connect to the network: WiFi, mobile network, VPN provider - the more information you can provide the better.
+
+- app version and platform. For mobile apps, it would help if you can make a screen recording from both devices during unsuccessful calls and share with us.
+
+- if the issue is on desktop app, which browser is used for calls. In this case also please check browser console during the call and send us the log, ideally from both sides of the unsuccessful calls.
+
+Thank you for helping us debug and improve calls.
+
+### Audio or video calls without e2e encryption
+
+During the call, the app indicates whether or not the call has end-to-end encryption.
+
+If one of the call parties uses Android (or desktop) app, the call would use Android system webview (or browser). Some older systems do not support media stream encryption, in which case the call will connect without it.
+
+To determine whether it is the limitation of your, your contact's or both devices:
+- if some of your calls have e2e encryption but some don't, then it's certainly the old webview version or browser of your contacts - please ask them to upgrade.
+- if you are not sure, you can check at what point "no e2e encryption" appears:
+  - if it is shown when the call rings on your device, then your contact's device does not support call encryption.
+  - if it is shown on your screen as soon as you start the call, then your device does not support call encryption.
+  - if in the beginning of the call your device shows "e2e encryption" but when your contact accepts the call it changes to "no e2e encryption", then it is only your contact's device that does not support it.
+
+You need to upgrade webview (some Android systems allow it), Android system or the device to have support for e2e encryption in the calls - all modern WebViews (and browsers) support it.
+
+### I clicked the link to connect, but could not connect
+
+If you confirmed the connection in the app, pending connection will be shown in the list of chats - you can assign the name to it, so you know who it was when your contact is connected (e.g., if they choose some name you don't recognize).
+
+For connection to complete, your contact has to be online and have the app running - please ask them to open the app, and try to have the app open at the same time - it will help to complete the connection faster.
+
+Once the connection is established you don't need to be online at the same time to send messages.
+
+### I do not know my database passphrase
+
+If you are prompted to enter database passphrase and you do not know it, this could have happened due to:
+- You may have forgotten the passphrase. (There is no other way to access your data).
+- Migration of app data from one device to another while using unsupported migration process, e.g. via iCloud backup. Use SimpleX Chat's own migration process in the app Settings.
+
+In the previous desktop app versions it could also happen in case of error during SimpleX Chat installation.
+
+You can resolve it by deleting the app's database: (WARNING: this results in deletion of all profiles, contacts and messages)
+- on Android/iOS, uninstall the app and install it again.
+- on Windows, delete folder `C:\AppData\Roaming\SimpleX`, you can find it by pressing Windows key + R and entering `%appdata%`.
+- on Linux/Mac, delete directories `~/.local/share/simplex` and `~/.config/simplex`, where `~` represents your home directory (/home/user)
+- on Flatpak, delete directory `~/.var/app/chat.simplex.simplex`.
+
+### My mobile app does not connect to desktop app
+
+1. Check that both devices are connected to the same network (e.g., it won't work if mobile is connected to mobile Internet and desktop to WiFi).
+2. If you use VPN on mobile, allow connections to local network in your VPN settings, or disable VPN.
+3. Allow SimpleX Chat on desktop to accept network connections in system firewall settings. You may choose a specific port in desktop app to accept connections, by default it uses a random port every time.
+4. Check that your WiFi router allows connections between devices (e.g., it may have an option for "device isolation", or similar).
+5. If you see an error "certificate expired", please check that your device clocks are synchronized within a few seconds.
+6. If iOS app fails to connect and shows an error containing "no route", check that local network connections are allowed for the app in system settings.
+
+Also see this post: https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol
+
+If none of the suggestions work for you, you can create a separate profile on each device and create a small group inviting both of your device profiles and your contact.
+
+## Privacy and security
+
+### Does SimpleX support post quantum cryptography?
+
+Yes! Please read more about how quantum-resistant encryption is added to SimpleX Chat and about various properties of end-to-end encryption in [this post](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md).
+
+### Why can't I use the same profile on different devices?
+
+SimpleX Chat apps support [linking of mobile and desktop apps](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol) via secure quantum-resistant protocol. It allows using the profile on your mobile device from desktop clients.
+
+Seamlessly and securely using the same profile from two or more devices is a complex and unsolved problem. All apps that provide multi-device support do so at a cost of compromising security of end-to-end encryption. E.g., Session removed the Double Ratchet algorithm entirely to enable multi-device support, sacrificing forward secrecy. Signal provides multi-device support with Double Ratchet algorithm, but by [compromising its "break-in recovery" property](https://eprint.iacr.org/2021/626.pdf) (aka post-compromise security).
+
+To the best of our knowledge there is no end-to-end encrypted messenger that solved this problem without compromising security, but we believe that the solution is possible. We have considered several approaches:
+
+1. Convert each direct conversation into a group, where each device participates as a member. This is the approach that Signal and WhatsApp use, and while Signal implementation does not protect from a temporary compromise of long-term identity key (break-in recovery), such protection is possible. The downside of this approach is that the contacts and groups you participate in would know which device you use. Another possible attack is to send different messages to different devices, or to send messages to some devices but not to the others. This could lead to message history inconsistency or enable targeted attacks.
+
+2. Store the state of the Double Ratchet algorithm for each conversation in an encrypted container on the server, allowing concurrent access and modification by each device for encrypting and decrypting messages. We did not see this approach used in any of the messaging apps, but it is technically viable. This approach has no downsides of the first, but it would increase the time it takes to send and to receive messages, as each message would require additional access to the server.
+
+3. "Thin client" approach when user profile is stored on the server. The main challenge with this approach is to prevent the server knowing who connects to whom.
+
+Whichever approach we choose for multi-device support, it requires careful design and implementation, and there is no existing secure solution to copy from. While we value usability very highly, we will not be improving usability in a way that compromises users' security. We will take a slower path of designing and implementing a solution for multi-device that achieves a better trade-off between usability and security than currently offered.
+
+In the meantime, here are several secure options to enhance usability:
+- link mobile profiles with desktop app. It does not compromise security in any way.
+- create small groups with trusted contacts. These contacts would still know which device you use when you send the message, but it won't be shared with all contacts and groups you participate in. This approach is also secure, and it prevents devices being added to the conversation without user noticing.
+- use "[business address](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html#business-chats)" - the app would create a new small group with everybody who connects to you via your address, and you will be able to add your other devices to these groups.
+
+While these approaches are not as convenient as seamless multi-device support offered by other apps, they also do not compromise security to achieve that convenience.
+
+### What user data can be provided on request?
+
+Our objective is to consistently ensure that no user data and absolute minimum of the metadata required for the network to function is available for disclosure by any infrastructure operators, under any circumstances.
+
+Please see our [Privacy Policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md) and [Transparency Reports](https://simplex.chat/transparency/index.html).
+
+### Does SimpleX protect my IP address?
+
+Yes!
+
+SimpleX Chat from version 6.0 uses *private message routing* whenever you send messages to unknown servers (all servers in app network settings, both enabled and not, are considered "known").
+
+For private routing to work, the servers chosen by your contacts (and by the group members in your groups) must be upgraded to the recent versions. Messaging servers include support for private routing from v5.8, but we recommend using the latest versions.
+
+If the servers didn't upgrade, the messages would temporarily fail to deliver. You will see an orange warning icon on the message, and you can decide if you want to deliver them by connecting to these servers directly (it would require changing network settings). At the time of writing (August 2024), all preset servers and absolute majority of self-hosted servers we can see on the network support private message routing.
+
+With private routing enabled, instead of connecting to your contact's server directly, your client would "instruct" one of the known servers to forward the message, preventing the destination server from observing your IP address.
+
+Your messages are additionally end-to-end encrypted between your client and the destination server, so that the forwarding server cannot observe the destination addresses and server responses – similarly to how onion routing works. Private message routing is, effectively, a two-hop onion packet routing.
+
+Also, this connection is protected from man-in-the-middle attack by the forwarding server, as your client will validate destination server certificate using its fingerprint in the server address.
+
+You can optionally enable private message routing for all servers in Advanced network settings to complicate traffic correlation for known servers too. This will be default once the clients are improved to "know about" and to take into account network server operators.
+
+See [this post](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md#private-message-routing) for more details about how private message routing works.
+
+### Doesn't private message routing reinvent Tor?
+
+No, it does not!
+
+It provides better privacy for messaging than Tor, and it can be used with and without Tor or other means to additionally protect your traffic from known servers as well.
+
+Tor, VPN and other transport overlay networks route sockets, by creating long-lived TCP circuits between you and the destination server. While it protects your IP address, it does not protect your activity within this circuit. E.g., if you visit a website via Tor, it can still observe all pages you view within a session. Likewise, if you were connecting directly to a messaging server via Tor, this server would be able to list all message queues you send messages to.
+
+Private message routing routes packets (each message is one 16kb packet), not sockets. Unlike Tor and VPN, it does not create circuits between your client and destination servers. The forwarding server creates one shared session between itself and the destination, and forwards all messages from you and other clients to that destination server, mixing messages from many clients into a single TCP session.
+
+As each message uses its own random encryption key and random (non-sequential) identifier, the destination server cannot link multiple message queue addresses to the same client. At the same time, the forwarding server cannot observe which (and how many) addresses on the destination server your client sends messages to, thanks to e2e encryption between the client and destination server. In that regard, this design is similar to onion routing, but with per-packet anonymity, not per-circuit.
+
+This design is similar to mixnets (e.g. [Nym network](https://nymtech.net)), and it is tailored to the needs of message routing, providing better transport anonymity than general-purpose networks, like Tor or VPN. You still can use Tor or VPN to connect to known servers, to protect your IP address from them.
+
+### Why don't you embed Tor in SimpleX Chat app?
+
+[Tor](https://www.torproject.org) is a fantastic transport overlay network - we believe it might be the best there is right now. If its [threat model](https://support.torproject.org/about/attacks-on-onion-routing/) works for you, you absolutely should use it - SimpleX Chat app supports Tor via SOCKS proxy [since v3.1](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.html#access-messaging-servers-via-tor), and SimpleX network servers can be available on both public and onion address at the same time [since v3.2](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.html#using-onion-server-addresses-with-tor), improving anonymity of the users who use Tor.
+
+If you host your messaging server on the onion address only, the users who don't use Tor would still be able to message you via private message routing - all preset servers are configured to forward messages to onion-only servers.
+
+But there are many reasons not to embed Tor in the app:
+- it increases response latency, error rate, and battery usage, and we believe that for most users enabling Tor by default would be a bad trade-off.
+- it would require us regularly updating Tor library in the app, and your Tor integrity would depend on us – you would be "putting too many eggs in one basket".
+- some networks restrict Tor traffic, so the app UI would have to support advanced Tor configuration, diverting our limited resources from the core app features that benefit all users.
+- some countries have legislative restrictions on Tor usage, so we would have to support multiple app versions, also increasing our costs and slowing down the progress.
+
+The last, but not the least, it would create an unfair competitive advantage to Tor. We believe in competition, and we want our users to be able to choose which transport overlay network to use, based on what network threat model works best for them.
+
+If you want to use Tor or any other overlay network, such as i2p, [Nym network](https://nymtech.net), [Katzenpost](https://katzenpost.network), etc., you need to research their limitations, because none of them provides absolute anonymity against all possible attackers.
+
+And if after that research you decide to use Tor, it takes about 2 minutes to install and start [Orbot app](https://guardianproject.info/apps/org.torproject.android/). We believe that if it seems complex, then you *should not* be using Tor - it is an advanced technology that can only improve your privacy and anonymity if you understand its limitations and know how to configure it.
+
+### Can I host my own relays?
+
+Of course! Please check these tutorials: [SMP server](https://simplex.chat/docs/server.md) and [XFTP server](https://simplex.chat/docs/xftp-server.md).
+
+## Funding and business model
+
+### How are you funded?
+
+SimpleX Chat Ltd is funded by private investors and venture capital. As an open-source project, it is also being generously supported by donations as well. Read the posts [from 2023](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md#how-is-it-funded-and-what-is-the-business-model) and [from 2024](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) for more details.
+
+### Why VCs?
+
+Here are some reflections on VC funding being a necessity for a project at this scale, as well as sustainability and profitability for longtime operations: https://www.poberezkin.com/posts/2023-10-31-why-privacy-impossible-without-venture-funding.html
+
+And another perspective from a team member on the delicate balance of venture-backed and nonprofit structures, and the plans for the SimpleX network protocols to evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and transparent governance:
+[https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html](https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md).
+
+### What will be the business model?
+
+We are focusing on product-market fit, and as such the business model is still a work in progress. However, the app will have a freemium model with extra features or capabilities for paid users (taking into consideration a potential formula like 5% paying $5/month is $3/user/year - ~90% gross profit margin).
+
+The other income stream would be via business services, for entities needing direct and customized support to integrate with the SimpleX protocol or related resources. There will also be a revenue-sharing model from customers to network operators, to provide an incentive for them to continue running nodes, which will increase decentralization and reliability of the network.
+
+Non-exploitative commercial models with fully open source code are not easy to achieve, and we’re committed to finding the best possible fit for our context. Everything will be fully communicated as this plan progresses.
diff --git a/faq/index.html b/faq/index.html
index 04694a221f..b4a200ba71 100644
--- a/faq/index.html
+++ b/faq/index.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/faq.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/fdroid.md b/fdroid.md
new file mode 100644
index 0000000000..296adf884e
--- /dev/null
+++ b/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stable and beta versions built by the developers
+
+To add it to your F-Droid client, scan the QR code or use this URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stable versions built by F-Droid.org
+
+The releases to this repo are done several days later.
+
+SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please [export](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) the chat database and re-install the app.
diff --git a/fdroid/index.html b/fdroid/index.html
index f729814b0d..066572c470 100644
--- a/fdroid/index.html
+++ b/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
                         <p>To add it to your F-Droid client, <span class="hide-on-mobile">scan the QR code or</span> use this URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stable versions built by F-Droid.org</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
                 <p class="mb-2">SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">export</a> the chat database and re-install the app.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/contact.md b/fi/contact.md
new file mode 100644
index 0000000000..d8b6805f43
--- /dev/null
+++ b/fi/contact.md
@@ -0,0 +1,66 @@
+# Sait osoitteen yhdistämistä varten SimpleX Chatissa
+
+## Skannaa QR-koodi SimpleX Chat -sovelluksella puhelimessasi tai tabletissasi.
+
+Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua — ne sisältyvät linkin URL:n hash-osaan.
+
+Et ole vielä ladannut SimpleX Chat -sovellusta?
+
+Käytä alla olevia linkkejä ladataksesi sovelluksen.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Skannaa QR-koodi mobiilisovelluksesta
+
+# Sait osoitteen yhdistämistä varten SimpleX Chatissa
+
+Yhteyden muodostaminen:
+
+Asenna SimpleX-sovellus
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid)
+
+1
+
+Yhdisty sovelluksessa
+
+Avaa Simplex-sovellus
+
+2
+
+Napauta sovelluksessa olevaa ‘yhdistä’-painiketta
+
+3
+
+## Skannaa QR-koodi SimpleX Chat -sovelluksella
+
+Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua —
+ne sisältyvät linkin URL:n hash-osaan.
+
+## Asentaminen SimpleX Chat terminaaliin
+
+Käytä tätä komentoa:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Katso SimpleX Chat GitHub-varasto ohjeet, miten ladata tai kääntää se lähdekoodista.
+
+---
+
+## Jos olet jo asentanut SimpleX Chatin terminaaliin
+
+Jos olet jo asentanut SimpleX Chatin terminaaliin v1.0.0+, kopioi alla oleva komento ja käytä sitä keskustelussa:
+
+## Liity SimpleX
+
+Kutsumme sinut mukaan keskusteluun
+
+[Liity REDDIT-yhteisöön](https://www.reddit.com/r/SimpleXChat/) [Liity GitHubissa](https://github.com/simplex-chat) [Tue meitä täällä lahjoituksilla](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Tilaa päivityksemme
+
+---
+
+Hanki SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid)
diff --git a/fi/contact/index.html b/fi/contact/index.html
index 18638affc6..a7807be5ac 100644
--- a/fi/contact/index.html
+++ b/fi/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Sait osoitteen yhdistämistä varten SimpleX Chatissa</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Skannaa QR-koodi SimpleX Chat -sovelluksella puhelimessasi tai tabletissasi.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua — ne sisältyvät linkin URL:n hash-osaan.
+                Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua &mdash; ne sisältyvät linkin URL:n hash-osaan.
             </p>
             <p class="text-grey-black dark:text-white text-base">Et ole vielä ladannut SimpleX Chat -sovellusta?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Käytä alla olevia linkkejä ladataksesi sovelluksen.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Asenna SimpleX-sovellus</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Napauta sovelluksessa olevaa <span class="text-active-blue">‘yhdistä’</span>-painiketta</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Napauta sovelluksessa olevaa <span class='text-active-blue'>‘yhdistä’</span>-painiketta</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Skannaa QR-koodi SimpleX Chat -sovelluksella</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua —<br> ne sisältyvät linkin URL:n hash-osaan.
+                            Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua &mdash;<br> ne sisältyvät linkin URL:n hash-osaan.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Asentaminen SimpleX Chat terminaaliin</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-varasto</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
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-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jos olet jo asentanut SimpleX Chatin terminaaliin</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Tilaa päivityksemme</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Syötä sähköpostiosoitteesi">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Hanki SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/fdroid.md b/fi/fdroid.md
new file mode 100644
index 0000000000..91515afddf
--- /dev/null
+++ b/fi/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat F-Droidin kautta
+
+### SimpleX Chat -varasto
+
+Kehittäjien luomat vakaat ja beta-versiot
+
+Lisätäksesi sen F-Droid-asiakkaaseesi, skannaa QR-koodi tai käytä tätä URL-osoitetta:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Allekirjoitusavaimen sormenjälki (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org -varasto
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Vakioversiot luotu F-Droid.org -varastoon
+
+Julkaisut tälle varastolle tehdään 1-2 päivää myöhemmin.
+
+SimpleX Chat ja F-Droid.org -varastot allekirjoittavat buildit eri avaimilla. Vaihtaaksesi, [vienti](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) keskustelutietokanta ja asenna sovellus uudelleen.
diff --git a/fi/fdroid/index.html b/fi/fdroid/index.html
index ccae5755b2..6c286cf5d3 100644
--- a/fi/fdroid/index.html
+++ b/fi/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat F-Droidin kautta</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Kehittäjien luomat vakaat ja beta-versiot</p>
-                        <p>Lisätäksesi sen F-Droid-asiakkaaseesi, <span class="hide-on-mobile">skannaa QR-koodi tai</span> käytä tätä URL-osoitetta:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Lisätäksesi sen F-Droid-asiakkaaseesi, <span class='hide-on-mobile'>skannaa QR-koodi tai</span> käytä tätä URL-osoitetta:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Allekirjoitusavaimen sormenjälki (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org -varasto</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Vakioversiot luotu F-Droid.org -varastoon</p>
                 <p class="mb-2">Julkaisut tälle varastolle tehdään 1-2 päivää myöhemmin.</p>
-                <p class="mb-2">SimpleX Chat ja F-Droid.org -varastot allekirjoittavat buildit eri avaimilla. Vaihtaaksesi, <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">vienti</a> keskustelutietokanta ja asenna sovellus uudelleen.</p>
+                <p class="mb-2">SimpleX Chat ja F-Droid.org -varastot allekirjoittavat buildit eri avaimilla. Vaihtaaksesi, <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>vienti</a> keskustelutietokanta ja asenna sovellus uudelleen.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/file.md b/fi/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/fi/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/fi/file/index.html b/fi/file/index.html
index 81d16b4673..526d1ece7c 100644
--- a/fi/file/index.html
+++ b/fi/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/index.html b/fi/index.html
index b457262383..125e503002 100644
--- a/fi/index.html
+++ b/fi/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/fi/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/fi/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/fi/index.md b/fi/index.md
new file mode 100644
index 0000000000..c15d1870af
--- /dev/null
+++ b/fi/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Lue lisää.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/fi/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/fi/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/fi/why)
+
+## Käyttäjiensä rahoittama
+
+Pysyäkseen riippumattomina suuret kanavat ja yhteisöt maksavat palvelimistaan.
+
+Ja käyttäjät voivat nyt sijoittaa SimpleX Chatiin — joukkorahoitus on käynnissä!
+
+[Sijoita SimpleX Chatiin](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/fi/invitation.md b/fi/invitation.md
new file mode 100644
index 0000000000..3e78acc604
--- /dev/null
+++ b/fi/invitation.md
@@ -0,0 +1,66 @@
+# Sait kertalinkini yhdistämistä varten SimpleX Chatissa
+
+## Skannaa QR-koodi SimpleX Chat -sovelluksella puhelimessasi tai tabletissasi.
+
+Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua — ne sisältyvät linkin URL:n hash-osaan.
+
+Et ole vielä ladannut SimpleX Chat -sovellusta?
+
+Käytä alla olevia linkkejä ladataksesi sovelluksen.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Skannaa QR-koodi mobiilisovelluksesta
+
+# Sait kertalinkini yhdistämistä varten SimpleX Chatissa
+
+Yhteyden muodostaminen:
+
+Asenna SimpleX-sovellus
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid)
+
+1
+
+Yhdisty sovelluksessa
+
+Avaa Simplex-sovellus
+
+2
+
+Napauta sovelluksessa olevaa ‘yhdistä’-painiketta
+
+3
+
+## Skannaa QR-koodi SimpleX Chat -sovelluksella
+
+Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua —
+ne sisältyvät linkin URL:n hash-osaan.
+
+## Asentaminen SimpleX Chat terminaaliin
+
+Käytä tätä komentoa:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Katso SimpleX Chat GitHub-varasto ohjeet, miten ladata tai kääntää se lähdekoodista.
+
+---
+
+## Jos olet jo asentanut SimpleX Chatin terminaaliin
+
+Jos olet jo asentanut SimpleX Chatin terminaaliin v1.0.0+, kopioi alla oleva komento ja käytä sitä keskustelussa:
+
+## Liity SimpleX
+
+Kutsumme sinut mukaan keskusteluun
+
+[Liity REDDIT-yhteisöön](https://www.reddit.com/r/SimpleXChat/) [Liity GitHubissa](https://github.com/simplex-chat) [Tue meitä täällä lahjoituksilla](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Tilaa päivityksemme
+
+---
+
+Hanki SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fi/fdroid)
diff --git a/fi/invitation/index.html b/fi/invitation/index.html
index 1d638c8c39..234f231482 100644
--- a/fi/invitation/index.html
+++ b/fi/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Sait kertalinkini yhdistämistä varten SimpleX Chatissa</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Skannaa QR-koodi SimpleX Chat -sovelluksella puhelimessasi tai tabletissasi.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua — ne sisältyvät linkin URL:n hash-osaan.
+                Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua &mdash; ne sisältyvät linkin URL:n hash-osaan.
             </p>
             <p class="text-grey-black dark:text-white text-base">Et ole vielä ladannut SimpleX Chat -sovellusta?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Käytä alla olevia linkkejä ladataksesi sovelluksen.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Asenna SimpleX-sovellus</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Napauta sovelluksessa olevaa <span class="text-active-blue">‘yhdistä’</span>-painiketta</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Napauta sovelluksessa olevaa <span class='text-active-blue'>‘yhdistä’</span>-painiketta</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Skannaa QR-koodi SimpleX Chat -sovelluksella</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua —<br> ne sisältyvät linkin URL:n hash-osaan.
+                            Tämän linkin julkiset avaimet ja viestijonon osoite eivät lähetä verkkoa pitkin, kun katsot tätä sivua &mdash;<br> ne sisältyvät linkin URL:n hash-osaan.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Asentaminen SimpleX Chat terminaaliin</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-varasto</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jos olet jo asentanut SimpleX Chatin terminaaliin</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Tilaa päivityksemme</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Syötä sähköpostiosoitteesi">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Hanki SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/messaging.md b/fi/messaging.md
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--- /dev/null
+++ b/fi/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Miksi SimpleX on ainutlaatuinen
+
+### Sinulla on täydellinen yksityisyys
+
+SimpleX suojaa profiilisi, yhteystietosi ja metatietosi yksityisyyden, piilottaen ne SimpleX-alustan palvelimilta ja kaikilta havainnoijilta.
+
+Toisin kuin millään muulla olemassa olevalla viestintäalustalla, SimpleX:llä ei ole tunnisteita käyttäjille — **ei edes satunnaisia numeroita**.
+
+### Olet suojattu roskapostilta ja väärinkäytöksiltä
+
+Koska sinulla ei ole tunnistetta tai kiinteää osoitetta SimpleX-alustalla, kukaan ei voi ottaa sinuun yhteyttä, ellet jaa kertakäyttöistä tai väliaikaista käyttäjäosoitetta, kuten QR-koodia tai linkkiä.
+
+### Sinä hallitset tietojasi
+
+SimpleX tallentaa kaikki käyttäjätiedot asiakaslaitteille **siirrettävässä salatussa tietokannan muodossa** — se voidaan siirtää toiseen laitteeseen.
+
+Päästä päähän salatut viestit säilytetään väliaikaisesti SimpleX-releay-palvelimilla, kunnes ne vastaanotetaan, minkä jälkeen ne poistetaan pysyvästi.
+
+### Omistat SimpleX-verkon
+
+SimpleX-verkko on täysin hajautettu ja riippumaton mistään kryptovaluutasta tai mistään muusta alustasta paitsi Internetistä.
+
+Voit **käyttää SimpleX:ää omien palvelimiesi kanssa** tai meidän tarjoamillamme palvelimilla — ja silti yhdistyä mihin tahansa käyttäjään.
+
+# Täysi yksityisyys identiteetistäsi, profiilistasi, kontakteistasi ja metatiedoista
+
+Toisin kuin muut viestintäalustat, SimpleX:llä ei ole **mitään tunnisteita käyttäjille**. Se ei luota puhelinnumeroihin, verkkotunnuksiin perustuviin osoitteisiin (kuten sähköposti tai XMPP), käyttäjänimiin, julkisiin avaimiin tai edes satunnaisiin numeroihin tunnistaakseen käyttäjänsä — emme tiedä kuinka monta ihmistä käyttää SimpleX-palvelimiamme.
+
+Viestien toimittamiseksi SimpleX käyttää [parittaisia nimettömiä osoitteita](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) kaksisuuntaisille viestijonoille, jotka ovat erilliset vastaanotetuille ja lähetetyille viesteille, yleensä eri palvelimien kautta.
+
+Tämä suunnittelu suojaa sitä, kenen kanssa kommunikoit, piilottamalla sen SimpleX-alustan palvelimilta ja kaikilta havainnoijilta. Piilottaaksesi IP-osoitteesi palvelimilta, voit **yhdistää SimpleX-palvelimiin Tor-verkon kautta**.
+
+# Paras suoja roskapostilta ja väärinkäytöksiltä
+
+Koska sinulla ei ole tunnistetta SimpleX-alustalla, kukaan ei voi ottaa sinuun yhteyttä, ellei jaa kertakäyttöistä tai väliaikaista käyttäjäosoitetta, kuten QR-koodia tai linkkiä.
+
+Jopa valinnaisen käyttäjäosoitteen kanssa, vaikka sitä voitaisiin käyttää roskapostiyhteyspyyntöjen lähettämiseen, voit vaihtaa sen tai poistaa sen kokonaan menettämättä mitään yhteyksiäsi.
+
+# Omistusoikeus, hallinta ja tietojesi turvallisuus
+
+SimpleX Chat tallentaa kaikki käyttäjätiedot vain asiakaslaitteille käyttäen **siirrettävää salattua tietokantamuotoa**, joka voidaan viedä ja siirtää mihin tahansa tuettuun laitteeseen.
+
+Päästä päähän salatut viestit säilytetään väliaikaisesti SimpleX-releay-palvelimilla, kunnes ne vastaanotetaan, minkä jälkeen ne poistetaan pysyvästi.
+
+Toisin kuin liitettyjen verkkojen palvelimet (sähköposti, XMPP tai Matrix), SimpleX-palvelimet eivät tallenna käyttäjätilejä, ne vain välittävät viestejä, suojaten molempien osapuolien yksityisyyttä.
+
+Lähetetyssä ja vastaanotetussa palvelimen liikenteessä ei ole yhteisiä tunnisteita tai salaustekstiä — jos joku havaitsee sen, he eivät voi helposti selvittää kuka kommunikoi kenen kanssa, vaikka TLS olisi vaarantunut.
+
+# Täysin hajautettu — käyttäjät omistavat SimpleX-verkon
+
+Voit **käyttää SimpleX:ää omien palvelimiesi kanssa** ja silti kommunikoida ihmisten kanssa, jotka käyttävät meille tarjottuja valmiiksi määritettyjä palvelimia.
+
+SimpleX-alusta käyttää [avoimeen protokollaan](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) ja tarjoaa [SDK:n chatbotien luomiseen](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), mahdollistaen palvelujen toteuttamisen, joiden kanssa käyttäjät voivat olla vuorovaikutuksessa SimpleX Chat -sovellusten kautta — odotamme innolla nähdä, millaisia SimpleX-palveluja voit rakentaa.
+
+Jos harkitset kehittämistä SimpleX-alustalle, esimerkiksi chat-botin luomista SimpleX-sovelluksen käyttäjille tai SimpleX Chat -kirjaston integrointia mobiilisovelluksiisi, ole hyvä ja [ota yhteyttä](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) saadaksesi neuvoja ja tukea.
+
+## Ominaisuudet
+
+Päästä päähän salattuja viestejä markdownin ja muokkaamisen kera
+
+Päästä päähän salattuja
+kuvia, videoita ja tiedostoja
+
+E2E-salatut hajautetut ryhmät — vain käyttäjät tietävät niiden olemassaolosta
+
+Päästä päähän salattuja ääniviestejä
+
+Katoavia viestejä
+
+Päästä päähän salattuja
+puheluita ja videopuheluja
+
+Kannettava salattu sovellustallennus — siirrä profiili toiseen laitteeseen
+
+Incognito-tila —
+ainutlaatuinen SimpleX Chatille
+
+## Mikä tekee SimpleX:stä yksityisen
+
+### Väliaikaiset nimettömät parittaiset tunnisteet
+
+SimpleX käyttää väliaikaisia nimettömiä parittaisia osoitteita ja tunnistetietoja jokaiselle käyttäjäkontaktille tai ryhmän jäsenelle.
+
+Se mahdollistaa viestien toimittamisen ilman käyttäjäprofiilitunnisteita, tarjoten paremman metatietosuojan kuin vaihtoehdot.
+
+### Avainvaihto kanavan ulkopuolella (out-of-band)
+
+Monet viestintäalustat ovat alttiita välikäden hyökkäyksille palvelimilta tai verkko-operaattoreilta.
+
+Estääkseen sen, SimpleX-sovellukset siirtävät yksittäiset avaimet kanavan ulkopuolella, kun jaat osoitteen linkkinä tai QR-koodina.
+
+### 2 kerrosta päästä päähän salattua viestintää
+
+Kaksoisruuviprotokolla —
+OTR-viestintä täydellisellä eteenpäinsalauksella ja murron palautuksella.
+
+NaCL-kryptolaatikko kussakin jonossa estämään liikenteen korrelaatiota viestijonojen välillä, jos TLS vaarantuu.
+
+### Viestin eheys vahvistus
+
+Viestien eheyden varmistamiseksi ne numeroituvat peräkkäin ja sisältävät edellisen viestin tiivisteen.
+
+Jos viestiä lisätään, poistetaan tai muutetaan, vastaanottaja saa ilmoituksen.
+
+### Lisäkerros palvelimen salaukselle
+
+Lisäkerros palvelimen salaukselle vastaanottajalle toimittaessa, jotta lähetetyn ja vastaanotetun palvelinliikenteen korrelaatio estyy, jos TLS vaarantuu.
+
+### Viestien sekoitus korrelaation vähentämiseksi
+
+SimpleX-palvelimet toimivat matalan viiveen sekoitussolmuina — saapuvilla ja lähtevillä viesteillä on erilainen järjestys.
+
+### Turvallinen tunnistettu TLS-tiedonsiirto
+
+Vain TLS 1.2/1.3 vahvoilla algoritmeilla käytetään asiakas-palvelin-yhteyksiin.
+
+Palvelimen sormenjälki ja kanavan sitominen estävät välikäden hyökkäykset ja toistohyökkäykset.
+
+Yhteyden jatkaminen on estetty istuntohyökkäysten estämiseksi.
+
+### Vaihtoehtoinen pääsy Torin kautta
+
+Suojataksesi IP-osoitettasi, voit käyttää palvelimia Tor-verkon tai jonkin muun kuljetuskerroksen päällä.
+
+Käyttääksesi SimpleX:ää Torin kautta, asenna [Orbot-sovellus](https://guardianproject.info/apps/org.torproject.android/) ja ota käyttöön SOCKS5-välityspalvelin (tai VPN [iOS:lla](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Yksisuuntaisia viestijonoja
+
+Jokainen viestijono siirtää viestejä yhteen suuntaan, eri lähettävillä ja vastaanottavilla osoitteilla.
+
+Se vähentää hyökkäysvektoreita verrattuna perinteisiin viestivälittimiin ja saatavilla oleviin metatietoihin.
+
+### Useita tasoja sisältöpakkauksia
+
+SimpleX käyttää sisältöpakkauksia jokaiselle salauskerrokselle estämään viestikoon hyökkäyksiä.
+
+Se saa erikokoiset viestit näyttämään samalta palvelimille ja verkon tarkkailijoille.
+
+## SimpleX Verkko
+
+SimpleX Chat tarjoaa parhaan yksityisyyden yhdistämällä P2P-verkkojen ja liitettävien verkkojen edut.
+
+### Toisin kuin P2P-verkot
+
+Kaikki viestit lähetetään palvelimien kautta, mikä sekä parantaa metatietojen yksityisyyttä että mahdollistaa luotettavan asynkronisen viestien toimituksen, samalla välttäen monia .
+
+# Verrattuna P2P-viestintäprotokolliin
+
+[P2P](https://fi.wikipedia.org/wiki/Vertaisverkko) viestintäprotokollilla ja sovelluksilla on erilaisia ongelmia, jotka tekevät niistä vähemmän luotettavia kuin SimpleX, monimutkaisempia analysoida ja alttiita useille hyökkäystyypeille.
+
+1. P2P-verkot luottavat jonkinlaiseen [DHT](https://fi.wikipedia.org/wiki/Hajautettu_tietokanta)-varianttiin viestien reitittämiseksi. DHT-suunnittelun on tasapainotettava toimituksen varmuutta ja latenssia. SimpleX:llä on parempi toimitusvarmuus ja pienempi latenssi kuin P2P-verkoilla, koska viesti voidaan toimittaa redundanssina useiden palvelimien kautta samanaikaisesti, käyttäen vastaanottajan valitsemia palvelimia. P2P-verkoissa viesti kulkee läpi *O(log N)* solmun sekvenssissä, käyttäen algoritmin valitsemia solmuja.
+2. SimpleX-toteutus, toisin kuin useimmat P2P-verkot, ei käytä globaaleja käyttäjätunnisteita millään tavalla, ei edes tilapäisiä, ja käyttää ainoastaan tilapäisiä parillisia tunnisteita, tarjoten paremman anonymiteetin ja metadatansuojan.
+3. P2P ei ratkaise [välikäden hyökkäys](https://fi.wikipedia.org/wiki/V%C3%A4lik%C3%A4den_hy%C3%B6kk%C3%A4ys) -ongelmaa, ja useimmat olemassa olevat toteutukset eivät käytä kanavan ulkopuolisia viestejä alkuperäiseen avaimenvaihtoon. SimpleX käyttää kanavan ulkopuolisia viestejä tai, joissakin tapauksissa, jo valmiiksi turvallisia ja luotettuja yhteyksiä alkuperäiseen avaimenvaihtoon.
+4. P2P-toteutukset voivat estyä joidenkin Internet-palveluntarjoajien (kuten [BitTorrent](https://fi.wikipedia.org/wiki/BitTorrent)) toimesta. SimpleX on kuljetusprotokollasta riippumaton - se voi toimia yleisten verkkoprotokollien kautta, kuten esimerkiksi WebSockets.
+5. Kaikki tunnetut P2P-verkot saattavat olla alttiita [Sybil-hyökkäykselle](https://fi.wikipedia.org/wiki/Sybil-hy%C3%B6kk%C3%A4ys), koska jokainen solmu on löydettävissä, ja verkko toimii kokonaisuutena. Tunnetut keinot sen lieventämiseksi vaativat joko keskitetyn komponentin tai kalliin [työn todistuksen](https://fi.wikipedia.org/wiki/Proof_of_work). SimpleX-verkolla ei ole palvelimen löydettävyyttä, se on fragmentoitunut ja toimii useina eristettyinä aliverkkoina, mikä tekee verkko-laajuisista hyökkäyksistä mahdottomia.
+6. P2P-verkot saattavat olla alttiita [DRDoS-hyökkäyksille](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), kun asiakkaat voivat lähettää uudelleen ja voimistaa liikennettä, mikä johtaa verkko-laajuiseen palvelunestohyökkäykseen. SimpleX-asiakkaat välittävät liikennettä vain tunnetuilta yhteyksiltä eivätkä voi olla käytettävissä hyökkääjänä liikenteen voimistamiseen koko verkossa.
+
+---
+
+### Toisin kuin liitettävät verkot
+
+SimpleXin relea-palvelimet EIVÄT tallenna käyttäjäprofiileja, yhteystietoja ja toimitettuja viestejä, ne EIVÄT yhdisty toisiinsa, eikä ole OLE olemassa palvelinluetteloa.
+
+---
+
+### SimpleX-verkko
+
+palvelimet tarjoavat yksisuuntaisia jonopalveluja yhdistääkseen käyttäjät, mutta niillä ei ole näkyvyyttä verkon yhteyskarttaan — ainoastaan käyttäjillä on.
+
+## SimpleX selitetynä
+
+1. Mitä käyttäjät kokevat
+
+2. Miten se toimii
+
+3. Mitä palvelimet näkevät
+
+1. Mitä käyttäjät kokevat
+
+Voit luoda yhteyshenkilöitä ja ryhmiä sekä käydä kaksisuuntaisia keskusteluja kuten missä tahansa muussa viestisovelluksessa.
+
+Kuinka se voi toimia yksisuuntaisten jonotusten kanssa ilman käyttäjäprofiilin tunnisteita?
+
+2. Miten se toimii
+
+Jokaista yhteyttä varten käytetään kahta erillistä viestintäjonon mahdollistavaa palvelinta viestien lähettämiseen ja vastaanottamiseen.
+
+Palvelimet välittävät viestejä vain yhteen suuntaan eivätkä saa kokonaiskuvaa käyttäjän keskustelusta tai yhteyksistä.
+
+3. Mitä palvelimet näkevät
+
+Palvelimilla on erilliset anonyymit tunnistetiedot kullekin jonolle, eivätkä ne tiedä, mille käyttäjille ne kuuluvat.
+
+Käyttäjät voivat lisäksi parantaa metadata-yksityisyyttään käyttämällä Tor-verkkoa palvelimiin yhdistämiseen, mikä estää IP-osoitteen perusteella tapahtuvan yhteyksien tekemisen.
+
+## Vertailu muihin protokolliin
+
+|  |  | Signal, suuret alustat | XMPP, Matrix | P2P-protokollat |
+| --- | --- | --- | --- | --- |
+| Vaati globaalin identiteetin | Ei - yksityinen | Kyllä [1] | Kyllä [2] | Kyllä [3] |
+| Mahdollisuus MITM-hyökkäykseen | Ei - turvallinen [4] | Kyllä [5] | Kyllä | Kyllä |
+| Riippuvuus DNS:stä | Ei - joustava | Kyllä | Kyllä | Ei |
+| Yksittäinen tai keskitetty verkko | Ei - hajautettu | Kyllä | Ei - liitetty [6] | Kyllä [7] |
+| Keskuskomponentti tai muu verkkoa koskeva hyökkäys | Ei - joustava | Kyllä | Kyllä [2] | Kyllä [8] |
+
+---
+
+1. Yleensä pohjautuu puhelinnumeroon, joissain tapauksissa käyttäjänimiin
+2. DNS-pohjaiset osoitteet
+3. Julkinen avain tai jokin muu maailmanlaajuisesti uniikki tunniste
+4. SimpleXin releapalvelimet eivät voi vaarantaa päästä päähän -salausta. Tarkista turvakoodi hyödyntääksesi hyökkäyssuojaa ylitys-kanavalla
+5. Jos operaattorin palvelimet ovat vaarantuneet. Tarkista turvakoodi Signalissa ja joissakin muissa sovelluksissa suojautuaksesi hyökkäykseltä
+6. Ei suojaa käyttäjien metatietojen yksityisyyttä
+7. Vaikka P2P-verkot ovat hajautettuja, ne eivät ole liitettäviä - ne toimivat yhtenä verkostona
+8. P2P-verkoilla on joko keskitetty auktoriteetti tai koko verkko voidaan vaarantaa — [katso täältä](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [katso täältä](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/fi/messaging/index.html b/fi/messaging/index.html
index 64ef28ac0e..5aaa96c041 100644
--- a/fi/messaging/index.html
+++ b/fi/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sinulla on täydellinen yksityisyys</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Olet suojattu roskapostilta ja väärinkäytöksiltä</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sinä hallitset tietojasi</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Omistat SimpleX-verkon</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Se mahdollistaa viestien toimittamisen ilman käyttäjäprofiilitunnisteita, tarjoten paremman metatietosuojan kuin vaihtoehdot.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
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@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Estääkseen sen, SimpleX-sovellukset siirtävät yksittäiset avaimet kanavan ulkopuolella, kun jaat osoitteen linkkinä tai QR-koodina.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
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@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL-kryptolaatikko kussakin jonossa estämään liikenteen korrelaatiota viestijonojen välillä, jos TLS vaarantuu.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
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@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Jos viestiä lisätään, poistetaan tai muutetaan, vastaanottaja saa ilmoituksen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
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@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Lisäkerros palvelimen salaukselle vastaanottajalle toimittaessa, jotta lähetetyn ja vastaanotetun palvelinliikenteen korrelaatio estyy, jos TLS vaarantuu.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX-palvelimet toimivat matalan viiveen sekoitussolmuina — saapuvilla ja lähtevillä viesteillä on erilainen järjestys.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
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@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Yhteyden jatkaminen on estetty istuntohyökkäysten estämiseksi.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
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@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Käyttääksesi SimpleX:ää Torin kautta, asenna <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot-sovellus</a> ja ota käyttöön SOCKS5-välityspalvelin (tai VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">iOS:lla</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
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@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Se vähentää hyökkäysvektoreita verrattuna perinteisiin viestivälittimiin ja saatavilla oleviin metatietoihin.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
                     </div>
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@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Se saa erikokoiset viestit näyttämään samalta palvelimille ja verkon tarkkailijoille.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
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@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/old/index.html b/fi/old/index.html
index 1690550d17..6bfa375f3e 100644
--- a/fi/old/index.html
+++ b/fi/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">Yksityisyys uudelleen määritelty</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -749,10 +754,10 @@ window.addEventListener('click',(e)=>{
     Monet käyttäjät ovat kysyneet: <em>jos SimpleX ei käytä käyttäjätunnisteita, miten se tietää minne viestit toimitetaan?</em>
 </p>
 <p>
-    Viestien toimittamiseen SimpleX ei käytä muiden alustojen käyttäjätunnuksia, vaan sen sijaan se käyttää väliaikaisia nimettömiä parittaisia tunnisteita viestijonoille, jotka ovat erillisiä jokaiselle yhteydelle — pitkäaikaisia tunnisteita ei ole.
+    Viestien toimittamiseen SimpleX ei käytä muiden alustojen käyttäjätunnuksia, vaan sen sijaan se käyttää väliaikaisia nimettömiä parittaisia tunnisteita viestijonoille, jotka ovat erillisiä jokaiselle yhteydelle &mdash; pitkäaikaisia tunnisteita ei ole.
 </p>
 <p>
-    Määrität, minkä palvelimen(t) valitset viestien vastaanottamiseen, sekä kontaktisi — palvelimet, joita käytät viestien lähettämiseen heille. Jokainen keskustelu käyttää todennäköisesti kahta eri palvelinta.
+    Määrität, minkä palvelimen(t) valitset viestien vastaanottamiseen, sekä kontaktisi &mdash; palvelimet, joita käytät viestien lähettämiseen heille. Jokainen keskustelu käyttää todennäköisesti kahta eri palvelinta.
 </p>
 <p>
     Tämä ratkaisu estää kaikkien käyttäjien metadatan vuotamisen sovellustason tasolla. Lisätäksesi yksityisyyttä ja suojataksesi IP-osoitteesi, voit yhdistää viestintäpalvelimiin Tor-verkon kautta.
@@ -761,7 +766,7 @@ window.addEventListener('click',(e)=>{
     Vain asiakaslaitteet tallentavat käyttäjäprofiilit, yhteystiedot ja ryhmät; viestit lähetetään 2-kerroksisella päästä päähän salauksella.
 </p>
 <p>
-    Lue lisää <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">SimpleX whitepaperista</a>.
+    Lue lisää <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>SimpleX whitepaperista</a>.
 </p>
                         </div>
                     </div>
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">Hanki SimpleX <a href="/downloads">desktop app</a></p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -931,8 +936,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Miksi yksityisyys on <span class="gradient-text">tärkeää</span></h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Metatietojesi yksityisyyden säilyttäminen — <span class="text-active-blue">keneen puhut</span> — suojaa sinua seuraavilta:</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Miksi yksityisyys on <span class='gradient-text'>tärkeää</span></h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Metatietojesi yksityisyyden säilyttäminen &mdash; <span class='text-active-blue'>keneen puhut</span> &mdash; suojaa sinua seuraavilta:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     Verkkokauppiaat tietävät, että alhaisempiin tuloluokkiin kuuluvat ihmiset todennäköisemmin tekevät kiireellisiä ostoksia, joten he voivat veloittaa korkeampia hintoja tai poistaa alennukset.
 </p>
 <p>
-    Jotkut rahoitus- ja vakuutusyhtiöt käyttävät sosiaalisia verkostoja määrittääkseen korkoja ja vakuutusmaksuja. Se tekee usein alhaisempiin tuloihin kuuluvien ihmisten maksavan enemmän — sitä kutsutaan <a href="https://fairbydesign.com/povertypremium/" target="_blank">'köyhyyslisäksi'</a>.
+    Jotkut rahoitus- ja vakuutusyhtiöt käyttävät sosiaalisia verkostoja määrittääkseen korkoja ja vakuutusmaksuja. Se tekee usein alhaisempiin tuloihin kuuluvien ihmisten maksavan enemmän &mdash; sitä kutsutaan <a href='https://fairbydesign.com/povertypremium/' target='_blank'>'köyhyyslisäksi'</a>.
 </p>
 <p>
     SimpleX-alusta suojaa yhteyksiesi yksityisyyttä paremmin kuin mikään vaihtoehto, estäen täysin yhteysverkkosi tulemisen saataville mille tahansa yrityksille tai organisaatioille. Vaikka ihmiset käyttävät SimpleX Chatin tarjoamia palvelimia, emme tiedä käyttäjien määrää tai heidän yhteyksiään.
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1001,7 +1006,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Ei niin kauan sitten huomasimme merkittävien vaalien olevan manipuloitavissa <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">kunnioitetun konsulttiyrityksen</a> toimesta, joka käytti sosiaalisia verkostoja vääristämään käsitystämme todellisesta maailmasta ja manipuloimaan ääniämme.
+    Ei niin kauan sitten huomasimme merkittävien vaalien olevan manipuloitavissa <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>kunnioitetun konsulttiyrityksen</a> toimesta, joka käytti sosiaalisia verkostoja vääristämään käsitystämme todellisesta maailmasta ja manipuloimaan ääniämme.
 </p>
 <p>
     Ollaksesi objektiivinen ja tehdäksesi itsenäisiä päätöksiä, sinun on hallittava tietotilaasi. Se on mahdollista vain, jos käytät yksityistä viestintäalustaa, jolla ei ole pääsyä sosiaaliseen verkostoosi.
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1045,16 +1050,16 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Kaikkien pitäisi välittää viestinnän yksityisyydestä ja turvallisuudesta — harmittomat keskustelut voivat asettaa sinut vaaraan, vaikka sinulla ei olisi mitään piilotettavaa.
+    Kaikkien pitäisi välittää viestinnän yksityisyydestä ja turvallisuudesta &mdash; harmittomat keskustelut voivat asettaa sinut vaaraan, vaikka sinulla ei olisi mitään piilotettavaa.
 </p>
 <p>
-    Yksi järkyttävimmistä tarinoista on <a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">Mohamedou Ould Salahi'n</a> kokemus, joka on kuvattu hänen muistelmissaan ja esitetty The Mauritanian -elokuvassa. Hänet laitettiin Guantanamo-leirille ilman oikeudenkäyntiä ja häntä kidutettiin siellä 15 vuotta puhelun jälkeen sukulaiselleen Afganistanissa, epäiltynä osallisuudesta 9/11-iskuihin, vaikka hän oli asunut Saksassa edelliset 10 vuotta.
+    Yksi järkyttävimmistä tarinoista on <a href='https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi' target='_blank'>Mohamedou Ould Salahi'n</a> kokemus, joka on kuvattu hänen muistelmissaan ja esitetty The Mauritanian -elokuvassa. Hänet laitettiin Guantanamo-leirille ilman oikeudenkäyntiä ja häntä kidutettiin siellä 15 vuotta puhelun jälkeen sukulaiselleen Afganistanissa, epäiltynä osallisuudesta 9/11-iskuihin, vaikka hän oli asunut Saksassa edelliset 10 vuotta.
 </p>
 <p>
-    Tavalliset ihmiset pidätetään siitä, mitä he jakavat verkossa, jopa 'anonyymien' tiliensä kautta, <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html" target="_blank">jopa demokraattisissa maissa</a>.
+    Tavalliset ihmiset pidätetään siitä, mitä he jakavat verkossa, jopa 'anonyymien' tiliensä kautta, <a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html' target='_blank'>jopa demokraattisissa maissa</a>.
 </p>
 <p>
-    Ei riitä, että käytät päästä päähän salattua viestintäsovellusta, meidän kaikkien pitäisi käyttää viestintäsovelluksia, jotka suojelevat henkilökohtaisten verkostojemme yksityisyyttä — keiden kanssa olemme yhteydessä.
+    Ei riitä, että käytät päästä päähän salattua viestintäsovellusta, meidän kaikkien pitäisi käyttää viestintäsovelluksia, jotka suojelevat henkilökohtaisten verkostojemme yksityisyyttä &mdash; keiden kanssa olemme yhteydessä.
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1083,7 +1088,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Miksi SimpleX on <span class="gradient-text">ainutlaatuinen</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Miksi SimpleX on <span class='gradient-text'>ainutlaatuinen</span></h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sinulla on täydellinen yksityisyys</h3>
                             </div>
 
@@ -1109,7 +1114,7 @@ window.addEventListener('click',(e)=>{
     SimpleX suojaa profiilisi, yhteystietosi ja metatietosi yksityisyyden, piilottaen ne SimpleX-alustan palvelimilta ja kaikilta havainnoijilta.
 </p>
 <p>
-    Toisin kuin millään muulla olemassa olevalla viestintäalustalla, SimpleX:llä ei ole tunnisteita käyttäjille — <strong>ei edes satunnaisia numeroita</strong>.
+    Toisin kuin millään muulla olemassa olevalla viestintäalustalla, SimpleX:llä ei ole tunnisteita käyttäjille &mdash; <strong>ei edes satunnaisia numeroita</strong>.
 </p>
 
                                     </div>
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Lisätietoja</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Piilota tiedot</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Olet suojattu roskapostilta ja väärinkäytöksiltä</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Lisätietoja</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Piilota tiedot</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sinä hallitset tietojasi</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleX tallentaa kaikki käyttäjätiedot asiakaslaitteille <strong>siirrettävässä salatussa tietokannan muodossa</strong> — se voidaan siirtää toiseen laitteeseen.
+    SimpleX tallentaa kaikki käyttäjätiedot asiakaslaitteille <strong>siirrettävässä salatussa tietokannan muodossa</strong> &mdash; se voidaan siirtää toiseen laitteeseen.
 </p>
 <p>
     Päästä päähän salatut viestit säilytetään väliaikaisesti SimpleX-releay-palvelimilla, kunnes ne vastaanotetaan, minkä jälkeen ne poistetaan pysyvästi.
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Lisätietoja</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Piilota tiedot</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Omistat SimpleX-verkon</h3>
                             </div>
 
@@ -1259,7 +1264,7 @@ window.addEventListener('click',(e)=>{
     SimpleX-verkko on täysin hajautettu ja riippumaton mistään kryptovaluutasta tai mistään muusta alustasta paitsi Internetistä.
 </p>
 <p>
-    Voit <strong>käyttää SimpleX:ää omien palvelimiesi kanssa</strong> tai meidän tarjoamillamme palvelimilla — ja silti yhdistyä mihin tahansa käyttäjään.
+    Voit <strong>käyttää SimpleX:ää omien palvelimiesi kanssa</strong> tai meidän tarjoamillamme palvelimilla &mdash; ja silti yhdistyä mihin tahansa käyttäjään.
 </p>
 
                                     </div>
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Lisätietoja</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Piilota tiedot</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1320,10 +1325,10 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Toisin kuin muut viestintäalustat, SimpleX:llä ei ole <strong>mitään tunnisteita käyttäjille</strong>. Se ei luota puhelinnumeroihin, verkkotunnuksiin perustuviin osoitteisiin (kuten sähköposti tai XMPP), käyttäjänimiin, julkisiin avaimiin tai edes satunnaisiin numeroihin tunnistaakseen käyttäjänsä — emme tiedä kuinka monta ihmistä käyttää SimpleX-palvelimiamme.
+    Toisin kuin muut viestintäalustat, SimpleX:llä ei ole <strong>mitään tunnisteita käyttäjille</strong>. Se ei luota puhelinnumeroihin, verkkotunnuksiin perustuviin osoitteisiin (kuten sähköposti tai XMPP), käyttäjänimiin, julkisiin avaimiin tai edes satunnaisiin numeroihin tunnistaakseen käyttäjänsä &mdash; emme tiedä kuinka monta ihmistä käyttää SimpleX-palvelimiamme.
 </p>
 <p>
-    Viestien toimittamiseksi SimpleX käyttää <a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">parittaisia nimettömiä osoitteita</a> kaksisuuntaisille viestijonoille, jotka ovat erilliset vastaanotetuille ja lähetetyille viesteille, yleensä eri palvelimien kautta.
+    Viestien toimittamiseksi SimpleX käyttää <a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>parittaisia nimettömiä osoitteita</a> kaksisuuntaisille viestijonoille, jotka ovat erilliset vastaanotetuille ja lähetetyille viesteille, yleensä eri palvelimien kautta.
 </p>
 <p>
     Tämä suunnittelu suojaa sitä, kenen kanssa kommunikoit, piilottamalla sen SimpleX-alustan palvelimilta ja kaikilta havainnoijilta. Piilottaaksesi IP-osoitteesi palvelimilta, voit <strong>yhdistää SimpleX-palvelimiin Tor-verkon kautta</strong>.
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     Toisin kuin liitettyjen verkkojen palvelimet (sähköposti, XMPP tai Matrix), SimpleX-palvelimet eivät tallenna käyttäjätilejä, ne vain välittävät viestejä, suojaten molempien osapuolien yksityisyyttä.
 </p>
 <p>
-    Lähetetyssä ja vastaanotetussa palvelimen liikenteessä ei ole yhteisiä tunnisteita tai salaustekstiä — jos joku havaitsee sen, he eivät voi helposti selvittää kuka kommunikoi kenen kanssa, vaikka TLS olisi vaarantunut.
+    Lähetetyssä ja vastaanotetussa palvelimen liikenteessä ei ole yhteisiä tunnisteita tai salaustekstiä &mdash; jos joku havaitsee sen, he eivät voi helposti selvittää kuka kommunikoi kenen kanssa, vaikka TLS olisi vaarantunut.
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Täysin hajautettu — käyttäjät omistavat SimpleX-verkon</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Täysin hajautettu &mdash; käyttäjät omistavat SimpleX-verkon</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     Voit <strong>käyttää SimpleX:ää omien palvelimiesi kanssa</strong> ja silti kommunikoida ihmisten kanssa, jotka käyttävät meille tarjottuja valmiiksi määritettyjä palvelimia.
 </p>
 <p>
-    SimpleX-alusta käyttää <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">avoimeen protokollaan</a> ja tarjoaa <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK:n chatbotien luomiseen</a>, mahdollistaen palvelujen toteuttamisen, joiden kanssa käyttäjät voivat olla vuorovaikutuksessa SimpleX Chat -sovellusten kautta — odotamme innolla nähdä, millaisia SimpleX-palveluja voit rakentaa.
+    SimpleX-alusta käyttää <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>avoimeen protokollaan</a> ja tarjoaa <a href='https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript' target='_blank'>SDK:n chatbotien luomiseen</a>, mahdollistaen palvelujen toteuttamisen, joiden kanssa käyttäjät voivat olla vuorovaikutuksessa SimpleX Chat -sovellusten kautta &mdash; odotamme innolla nähdä, millaisia SimpleX-palveluja voit rakentaa.
 </p>
 <p>
-    Jos harkitset kehittämistä SimpleX-alustalle, esimerkiksi chat-botin luomista SimpleX-sovelluksen käyttäjille tai SimpleX Chat -kirjaston integrointia mobiilisovelluksiisi, ole hyvä ja <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">ota yhteyttä</a> saadaksesi neuvoja ja tukea.
+    Jos harkitset kehittämistä SimpleX-alustalle, esimerkiksi chat-botin luomista SimpleX-sovelluksen käyttäjille tai SimpleX Chat -kirjaston integrointia mobiilisovelluksiisi, ole hyvä ja <a href='https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>ota yhteyttä</a> saadaksesi neuvoja ja tukea.
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Päästä päähän salattuja viestejä markdownin ja muokkaamisen kera</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Päästä päähän salattuja<br>kuvia, videoita ja tiedostoja</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">E2E-salatut hajautetut ryhmät — vain käyttäjät tietävät niiden olemassaolosta</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">E2E-salatut hajautetut ryhmät &mdash; vain käyttäjät tietävät niiden olemassaolosta</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Päästä päähän salattuja ääniviestejä</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Katoavia viestejä</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Päästä päähän salattuja<br>puheluita ja videopuheluja</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Kannettava salattu sovellustallennus — siirrä profiili toiseen laitteeseen</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Kannettava salattu sovellustallennus &mdash; siirrä profiili toiseen laitteeseen</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Incognito-tila —<br>ainutlaatuinen SimpleX Chatille</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Incognito-tila &mdash;<br>ainutlaatuinen SimpleX Chatille</p>
             </div>
             
         </div>
@@ -1570,7 +1575,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Mikä tekee SimpleX:stä <span class="gradient-text">yksityisen</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Mikä tekee SimpleX:stä <span class='gradient-text'>yksityisen</span></h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Väliaikaiset nimettömät parittaiset tunnisteet</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Avainvaihto kanavan ulkopuolella<br> (out-of-band)</h3>
@@ -1614,14 +1619,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">2 kerrosta päästä päähän salattua viestintää</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">Kaksoisruuviprotokolla —<br>OTR-viestintä täydellisellä eteenpäinsalauksella ja murron palautuksella.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Kaksoisruuviprotokolla &mdash;<br>OTR-viestintä täydellisellä eteenpäinsalauksella ja murron palautuksella.</p>
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL-kryptolaatikko kussakin jonossa estämään liikenteen korrelaatiota viestijonojen välillä, jos TLS vaarantuu.</p>
                             
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Viestin eheys<br>vahvistus</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Lisäkerros palvelimen salaukselle</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Viestien sekoitus<br>korrelaation vähentämiseksi</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX-palvelimet toimivat matalan viiveen sekoitussolmuina — saapuvilla ja lähtevillä viesteillä on erilainen järjestys.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX-palvelimet toimivat matalan viiveen sekoitussolmuina &mdash; saapuvilla ja lähtevillä viesteillä on erilainen järjestys.</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">Napauta sulkeaksesi</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Turvallinen tunnistettu<br>TLS-tiedonsiirto</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Vaihtoehtoinen pääsy Torin kautta</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Yksisuuntaisia<br>viestijonoja</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Useita tasoja<br>sisältöpakkauksia</h3>
@@ -1774,14 +1779,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class="gradient-text">Verkko</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class='gradient-text'>Verkko</span></h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">SimpleX Chat tarjoaa parhaan yksityisyyden yhdistämällä P2P-verkkojen ja liitettävien verkkojen edut.</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">Toisin kuin P2P-verkot</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         Kaikki viestit lähetetään palvelimien kautta, mikä sekä parantaa metatietojen yksityisyyttä että mahdollistaa luotettavan asynkronisen viestien toimituksen, samalla välttäen monia <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">P2P-verkkojen ongelmia</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">Verrattuna P2P-viestintäprotokolliin</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1797,26 +1802,26 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    <a href="https://fi.wikipedia.org/wiki/Vertaisverkko">P2P</a> viestintäprotokollilla ja sovelluksilla on erilaisia ongelmia, jotka tekevät niistä vähemmän luotettavia kuin SimpleX, monimutkaisempia analysoida ja alttiita useille hyökkäystyypeille.
+    <a href='https://fi.wikipedia.org/wiki/Vertaisverkko'>P2P</a> viestintäprotokollilla ja sovelluksilla on erilaisia ongelmia, jotka tekevät niistä vähemmän luotettavia kuin SimpleX, monimutkaisempia analysoida ja alttiita useille hyökkäystyypeille.
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
-        P2P-verkot luottavat jonkinlaiseen <a href="https://fi.wikipedia.org/wiki/Hajautettu_tietokanta">DHT</a>-varianttiin viestien reitittämiseksi. DHT-suunnittelun on tasapainotettava toimituksen varmuutta ja latenssia. SimpleX:llä on parempi toimitusvarmuus ja pienempi latenssi kuin P2P-verkoilla, koska viesti voidaan toimittaa redundanssina useiden palvelimien kautta samanaikaisesti, käyttäen vastaanottajan valitsemia palvelimia. P2P-verkoissa viesti kulkee läpi <em>O(log N)</em> solmun sekvenssissä, käyttäen algoritmin valitsemia solmuja.
+        P2P-verkot luottavat jonkinlaiseen <a href='https://fi.wikipedia.org/wiki/Hajautettu_tietokanta'>DHT</a>-varianttiin viestien reitittämiseksi. DHT-suunnittelun on tasapainotettava toimituksen varmuutta ja latenssia. SimpleX:llä on parempi toimitusvarmuus ja pienempi latenssi kuin P2P-verkoilla, koska viesti voidaan toimittaa redundanssina useiden palvelimien kautta samanaikaisesti, käyttäen vastaanottajan valitsemia palvelimia. P2P-verkoissa viesti kulkee läpi <em>O(log N)</em> solmun sekvenssissä, käyttäen algoritmin valitsemia solmuja.
     </li>
     <li>
         SimpleX-toteutus, toisin kuin useimmat P2P-verkot, ei käytä globaaleja käyttäjätunnisteita millään tavalla, ei edes tilapäisiä, ja käyttää ainoastaan tilapäisiä parillisia tunnisteita, tarjoten paremman anonymiteetin ja metadatansuojan.
     </li>
     <li>
-        P2P ei ratkaise <a href="https://fi.wikipedia.org/wiki/V%C3%A4lik%C3%A4den_hy%C3%B6kk%C3%A4ys">välikäden hyökkäys</a> -ongelmaa, ja useimmat olemassa olevat toteutukset eivät käytä kanavan ulkopuolisia viestejä alkuperäiseen avaimenvaihtoon. SimpleX käyttää kanavan ulkopuolisia viestejä tai, joissakin tapauksissa, jo valmiiksi turvallisia ja luotettuja yhteyksiä alkuperäiseen avaimenvaihtoon.
+        P2P ei ratkaise <a href='https://fi.wikipedia.org/wiki/V%C3%A4lik%C3%A4den_hy%C3%B6kk%C3%A4ys'>välikäden hyökkäys</a> -ongelmaa, ja useimmat olemassa olevat toteutukset eivät käytä kanavan ulkopuolisia viestejä alkuperäiseen avaimenvaihtoon. SimpleX käyttää kanavan ulkopuolisia viestejä tai, joissakin tapauksissa, jo valmiiksi turvallisia ja luotettuja yhteyksiä alkuperäiseen avaimenvaihtoon.
     </li>
     <li>
-        P2P-toteutukset voivat estyä joidenkin Internet-palveluntarjoajien (kuten <a href="https://fi.wikipedia.org/wiki/BitTorrent">BitTorrent</a>) toimesta. SimpleX on kuljetusprotokollasta riippumaton - se voi toimia yleisten verkkoprotokollien kautta, kuten esimerkiksi WebSockets.
+        P2P-toteutukset voivat estyä joidenkin Internet-palveluntarjoajien (kuten <a href='https://fi.wikipedia.org/wiki/BitTorrent'>BitTorrent</a>) toimesta. SimpleX on kuljetusprotokollasta riippumaton - se voi toimia yleisten verkkoprotokollien kautta, kuten esimerkiksi WebSockets.
     </li>
     <li>
-        Kaikki tunnetut P2P-verkot saattavat olla alttiita <a href="https://fi.wikipedia.org/wiki/Sybil-hy%C3%B6kk%C3%A4ys">Sybil-hyökkäykselle</a>, koska jokainen solmu on löydettävissä, ja verkko toimii kokonaisuutena. Tunnetut keinot sen lieventämiseksi vaativat joko keskitetyn komponentin tai kalliin <a href="https://fi.wikipedia.org/wiki/Proof_of_work">työn todistuksen</a>. SimpleX-verkolla ei ole palvelimen löydettävyyttä, se on fragmentoitunut ja toimii useina eristettyinä aliverkkoina, mikä tekee verkko-laajuisista hyökkäyksistä mahdottomia.
+        Kaikki tunnetut P2P-verkot saattavat olla alttiita <a href='https://fi.wikipedia.org/wiki/Sybil-hy%C3%B6kk%C3%A4ys'>Sybil-hyökkäykselle</a>, koska jokainen solmu on löydettävissä, ja verkko toimii kokonaisuutena. Tunnetut keinot sen lieventämiseksi vaativat joko keskitetyn komponentin tai kalliin <a href='https://fi.wikipedia.org/wiki/Proof_of_work'>työn todistuksen</a>. SimpleX-verkolla ei ole palvelimen löydettävyyttä, se on fragmentoitunut ja toimii useina eristettyinä aliverkkoina, mikä tekee verkko-laajuisista hyökkäyksistä mahdottomia.
     </li>
     <li>
-        P2P-verkot saattavat olla alttiita <a href="https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent">DRDoS-hyökkäyksille</a>, kun asiakkaat voivat lähettää uudelleen ja voimistaa liikennettä, mikä johtaa verkko-laajuiseen palvelunestohyökkäykseen. SimpleX-asiakkaat välittävät liikennettä vain tunnetuilta yhteyksiltä eivätkä voi olla käytettävissä hyökkääjänä liikenteen voimistamiseen koko verkossa.
+        P2P-verkot saattavat olla alttiita <a href='https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent'>DRDoS-hyökkäyksille</a>, kun asiakkaat voivat lähettää uudelleen ja voimistaa liikennettä, mikä johtaa verkko-laajuiseen palvelunestohyökkäykseen. SimpleX-asiakkaat välittävät liikennettä vain tunnetuilta yhteyksiltä eivätkä voi olla käytettävissä hyökkääjänä liikenteen voimistamiseen koko verkossa.
     </li>
 </ol>
                         </div>
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">Toisin kuin liitettävät verkot</h3>
@@ -1862,13 +1867,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">SimpleX-verkko</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        palvelimet tarjoavat <span class="text-active-blue">yksisuuntaisia jonopalveluja</span> yhdistääkseen käyttäjät, mutta niillä ei ole näkyvyyttä verkon yhteyskarttaan — ainoastaan käyttäjillä on.
+                        palvelimet tarjoavat <span class='text-active-blue'>yksisuuntaisia jonopalveluja</span> yhdistääkseen käyttäjät, mutta niillä ei ole näkyvyyttä verkon yhteyskarttaan &mdash; ainoastaan käyttäjillä on.
                     </p>
                 </div>
             </div>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. Mitä käyttäjät kokevat</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Voit luoda yhteyshenkilöitä ja ryhmiä sekä käydä kaksisuuntaisia keskusteluja kuten missä tahansa muussa viestisovelluksessa.
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. Miten se toimii</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Jokaista yhteyttä varten käytetään kahta erillistä viestintäjonon mahdollistavaa palvelinta viestien lähettämiseen ja vastaanottamiseen.
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. Mitä palvelimet näkevät</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Palvelimilla on erilliset anonyymit tunnistetiedot kullekin jonolle, eivätkä ne tiedä, mille käyttäjille ne kuuluvat.
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal, suuret alustat</th>
                         <th class="pb-4">XMPP, Matrix</th>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Tilaa päivityksemme</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Syötä sähköpostiosoitteesi">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">Hanki SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fi/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fi/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fi/why.md b/fi/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/fi/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/fi/why/index.html b/fi/why/index.html
index 3dc57f93f9..d8c076a319 100644
--- a/fi/why/index.html
+++ b/fi/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fi/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/file.md b/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/file/index.html b/file/index.html
index 2a823bae39..6498dea79c 100644
--- a/file/index.html
+++ b/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/contact.md b/fr/contact.md
new file mode 100644
index 0000000000..2bd99abfb8
--- /dev/null
+++ b/fr/contact.md
@@ -0,0 +1,66 @@
+# Vous avez reçu une adresse pour vous connecter sur SimpleX Chat
+
+## Scannez le code QR avec l'application SimpleX Chat sur votre téléphone ou votre tablette.
+
+Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page — elles sont contenues dans le fragment de hachage de l'URL du lien.
+
+Vous n'avez pas encore téléchargé SimpleX Chat ?
+
+Utilisez les liens ci-dessous pour télécharger l'application.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scanner le code QR depuis l'application mobile
+
+# Vous avez reçu une adresse pour vous connecter sur SimpleX Chat
+
+Pour établir une connexion :
+
+Installer l'application SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid)
+
+1
+
+Se connecter dans l'application
+
+Ouvrir l’application SimpleX
+
+2
+
+Appuyez sur le bouton « se connecter » dans l’application
+
+3
+
+## Scannez le code QR avec l'application SimpleX Chat
+
+Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page —
+elles sont contenus dans le fragment de hachage de l'URL du lien.
+
+## Installation de SimpleX Chat sur un terminal
+
+Utilisez cette commande :
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Voir SimpleX Chat Dépôt GitHub pour savoir comment télécharger ou compiler l’application à partir du code source.
+
+---
+
+## Si vous avez déjà installé SimpleX Chat pour le terminal
+
+Si vous avez déjà installé Chat SimpleX pour le terminal v1.0.0+, copiez la commande ci-dessous et utilisez-la dans le chat :
+
+## Rejoindre SimpleX
+
+Nous vous invitons à rejoindre la conversation
+
+[Rejoindre la communauté REDDIT](https://www.reddit.com/r/SimpleXChat/) [Rejoignez-nous sur GitHub](https://github.com/simplex-chat) [Faites un don ici pour nous aider](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Inscrivez-vous pour recevoir nos mises à jour
+
+---
+
+Obtenir SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid)
diff --git a/fr/contact/index.html b/fr/contact/index.html
index aaadddf9e9..36971df542 100644
--- a/fr/contact/index.html
+++ b/fr/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Vous avez reçu une adresse pour vous connecter sur SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scannez le code QR avec l'application SimpleX Chat sur votre téléphone ou votre tablette.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page — elles sont contenues dans le fragment de hachage de l'URL du lien.
+                Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page &mdash; elles sont contenues dans le fragment de hachage de l'URL du lien.
             </p>
             <p class="text-grey-black dark:text-white text-base">Vous n'avez pas encore téléchargé SimpleX Chat ?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Utilisez les liens ci-dessous pour télécharger l'application.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installer l'application SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Appuyez sur le bouton <span class="text-active-blue">«&nbsp;se connecter&nbsp;»</span> dans l’application</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Appuyez sur le bouton <span class="text-active-blue">« se connecter »</span> dans l’application</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scannez le code QR avec l'application SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page —<br> elles sont contenus dans le fragment de hachage de l'URL du lien.
+                            Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page &mdash;<br> elles sont contenus dans le fragment de hachage de l'URL du lien.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installation de SimpleX Chat sur un terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Dépôt GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Si vous avez déjà installé SimpleX Chat pour le terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Inscrivez-vous pour recevoir nos mises à jour</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Entrez votre adresse e-mail">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtenir SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/fdroid.md b/fr/fdroid.md
new file mode 100644
index 0000000000..0c62fe65a7
--- /dev/null
+++ b/fr/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### Dépot SimpleX Chat
+
+Versions stables et bêta crées par les développeurs
+
+Pour l’ajouter à votre client F-Droid, scannez le code QR ou utilisez cette URL :
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Empreinte de signature numérique (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Dépot F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Versions stables créées par F-Droid.org
+
+Les mises à jour de ce dépôt sont faites quelques jours plus tard.
+
+Les dépôts SimpleX Chat et F-Droid.org signent les versions avec des clés différentes. Pour passer de l’un à l’autre, veuillez [exporter](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) la base de données des chats et réinstaller l’application.
diff --git a/fr/fdroid/index.html b/fr/fdroid/index.html
index 87c0473f42..c5abd5f769 100644
--- a/fr/fdroid/index.html
+++ b/fr/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Versions stables et bêta crées par les développeurs</p>
-                        <p>Pour l’ajouter à votre client F-Droid, <span class="hide-on-mobile">scannez le code QR ou</span> utilisez cette URL&nbsp;:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Pour l’ajouter à votre client F-Droid, <span class="hide-on-mobile">scannez le code QR ou</span> utilisez cette URL :</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Empreinte de signature numérique (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Dépot F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Versions stables créées par F-Droid.org</p>
                 <p class="mb-2">Les mises à jour de ce dépôt sont faites quelques jours plus tard.</p>
                 <p class="mb-2">Les dépôts SimpleX Chat et F-Droid.org signent les versions avec des clés différentes. Pour passer de l’un à l’autre, veuillez <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exporter</a> la base de données des chats et réinstaller l’application.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/file.md b/fr/file.md
new file mode 100644
index 0000000000..a9003cbdb1
--- /dev/null
+++ b/fr/file.md
@@ -0,0 +1,31 @@
+# Transfert de fichiers SimpleX
+
+Glissez-déposez un fichier ici
+
+ou
+
+Choisir un fichier
+
+Max 100 Mo - [l’app SimpleX Chat](https://simplex.chat/downloads) prend en charge les fichiers jusqu’à 1 Go
+
+Envoyez des fichiers en toute sécurité avec un chiffrement de bout en bout — sans compte, sans suivi.
+
+## Obtenez SimpleX Chat — la messagerie la plus sécurisée et la plus respectueuse de la vie privée
+
+Le transfert de fichiers que vous venez d’utiliser repose sur le même protocole de routage des données que SimpleX Chat. L’application propose une messagerie chiffrée de bout en bout, des appels audio et vidéo, des groupes et l’envoi de fichiers. Aucun compte. Aucun numéro de téléphone. Aucun e-mail. Aucun identifiant de profil utilisateur.
+
+# Protocole XFTP : le transfert de fichiers le plus sécurisé
+
+### Aucun compte requis
+
+Chaque fragment de fichier utilise une nouvelle clé aléatoire. Les routeurs de données n’ont ni « utilisateurs » ni « fichiers » — ils transfèrent des fragments de fichiers chiffrés de taille fixe.
+
+### Chiffré trois fois dans votre navigateur
+
+La clé de chiffrement du fichier est présente uniquement dans le fragment de hachage de l’URL — votre navigateur ne l’envoie jamais à un serveur. Il existe trois couches de chiffrement : le transport TLS, le chiffrement par destinataire (clé éphémère unique par transfert) et le chiffrement de bout en bout des fichiers.
+
+### Routeurs de données indépendants
+
+Lorsqu’un fichier est découpé en fragments, il est transmis via des routeurs réseau gérés par des tiers indépendants. Aucun opérateur ne peut voir la taille réelle ou le nom du fichier. Même si un routeur est compromis, il ne peut voir que des fragments chiffrés de taille fixe. Les fragments de fichier sont mis en cache par les routeurs réseau pendant environ 48 heures.
+
+[Lire la spécification du protocole XFTP →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/fr/file/index.html b/fr/file/index.html
index c7acb77cfd..4b42251b90 100644
--- a/fr/file/index.html
+++ b/fr/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">Transfert de fichiers SimpleX</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Glissez-déposez un fichier ici</p>
@@ -675,8 +682,8 @@ window.addEventListener('click',(e)=>{
           <p>File available</p>
           <button class="btn">Télécharger</button>
           <div class="security-note">
-            <p>Ce fichier est chiffré — les routeurs de données ne voient jamais le contenu, le nom ni la taille du fichier.</p>
-            <p>La clé de chiffrement se trouve dans le fragment de hachage du lien — elle n’est jamais envoyée à aucun serveur.</p>
+            <p>Ce fichier est chiffré &mdash; les routeurs de données ne voient jamais le contenu, le nom ni la taille du fichier.</p>
+            <p>La clé de chiffrement se trouve dans le fragment de hachage du lien &mdash; elle n’est jamais envoyée à aucun serveur.</p>
             <p>Pour une meilleure sécurité, utilisez l’application <a href="https://simplex.chat/downloads">SimpleX Chat</a>.</p>
           </div>
         </div>
@@ -685,7 +692,7 @@ window.addEventListener('click',(e)=>{
     <script>if(location.hash.length>50){var a=document.getElementById("app"),t=document.getElementById("dl-placeholder");if(a&&t)a.replaceChildren(t.content.cloneNode(true))}</script>
     <script type="module" src="/file-assets/index.js"></script>
 
-    <p class="text-base text-center text-grey-black dark:text-white mt-10 max-w-[600px]">Envoyez des fichiers en toute sécurité avec un chiffrement de bout en bout — sans compte, sans suivi.</p>
+    <p class="text-base text-center text-grey-black dark:text-white mt-10 max-w-[600px]">Envoyez des fichiers en toute sécurité avec un chiffrement de bout en bout &mdash; sans compte, sans suivi.</p>
     <a href="javascript:void(0)" data-show-overlay="xftp-protocol" class="open-overlay-btn file-proto-link mt-3 block text-center">En savoir plus sur le protocole XFTP</a>
   </div>
 </section>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Obtenez SimpleX Chat — la messagerie la plus sécurisée et la plus respectueuse de la vie privée
+      Obtenez SimpleX Chat &mdash; la messagerie la plus sécurisée et la plus respectueuse de la vie privée
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       Le transfert de fichiers que vous venez d’utiliser repose sur le même protocole de routage des données que SimpleX Chat. L’application propose une messagerie chiffrée de bout en bout, des appels audio et vidéo, des groupes et l’envoi de fichiers. Aucun compte. Aucun numéro de téléphone. Aucun e-mail. Aucun identifiant de profil utilisateur.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/fr/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/fr/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -713,18 +720,18 @@ window.addEventListener('click',(e)=>{
     
     <div id="xftp-protocol" data-scroll-to="" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Protocole XFTP&nbsp;: le transfert de fichiers le plus sécurisé</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Protocole XFTP : le transfert de fichiers le plus sécurisé</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <div>
   <h3 class="font-bold text-lg mb-2">Aucun compte requis</h3>
-  <p>Chaque fragment de fichier utilise une nouvelle clé aléatoire. Les routeurs de données n’ont ni «&nbsp;utilisateurs&nbsp;» ni «&nbsp;fichiers&nbsp;» — ils transfèrent des fragments de fichiers chiffrés de taille fixe.</p>
+  <p>Chaque fragment de fichier utilise une nouvelle clé aléatoire. Les routeurs de données n’ont ni « utilisateurs » ni « fichiers » &mdash; ils transfèrent des fragments de fichiers chiffrés de taille fixe.</p>
 </div>
 <div>
   <h3 class="font-bold text-lg mb-2">Chiffré trois fois dans votre navigateur</h3>
-  <p>La clé de chiffrement du fichier est présente uniquement dans le fragment de hachage de l’URL — votre navigateur ne l’envoie jamais à un serveur. Il existe trois couches de chiffrement&nbsp;: le transport TLS, le chiffrement par destinataire (clé éphémère unique par transfert) et le chiffrement de bout en bout des fichiers.</p>
+  <p>La clé de chiffrement du fichier est présente uniquement dans le fragment de hachage de l’URL &mdash; votre navigateur ne l’envoie jamais à un serveur. Il existe trois couches de chiffrement : le transport TLS, le chiffrement par destinataire (clé éphémère unique par transfert) et le chiffrement de bout en bout des fichiers.</p>
 </div>
 <div>
   <h3 class="font-bold text-lg mb-2">Routeurs de données indépendants</h3>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/index.html b/fr/index.html
index 6ee1f57eed..9a3a1939f4 100644
--- a/fr/index.html
+++ b/fr/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/fr/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/fr/fdroid" title="Application SimpleX via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Version bêta de SimpleX pour iOS sur TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Version bêta de SimpleX pour iOS sur TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Audits de sécurité" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Maintenant</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Juin 2027</span>
diff --git a/fr/index.md b/fr/index.md
new file mode 100644
index 0000000000..5052af95b5
--- /dev/null
+++ b/fr/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Soyez Libre
+
+## Dans Votre Réseau
+
+Le premier réseau sans identifiants d'utilisateur.
+Vos contacts, groupes et canaux vous appartiennent.
+
+Investissez dans SimpleX Chat. [En savoir plus.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [Application SimpleX via F-Droid](https://simplex.chat/fr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Audits de sécurité](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Audit de
+sécurité
+
+[Messageries recommandées par Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Messageries recommandées par Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publications de Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Analyse de Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Entretien avec le podcast OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Personne ne voit avec qui vous parlez
+
+Même pas les serveurs – tous les messages ressemblent à du bruit aléatoire.
+
+Des dizaines de millions de messages envoyés en privé chaque jour.
+
+[En savoir plus sur la messagerie SimpleX](https://simplex.chat/fr/messaging)
+
+## Le réseau vous appartient
+
+Chaque contact et chaque groupe reste sur votre appareil, et non sur un serveur.
+
+Aucune entité ne contrôle le réseau – n'importe qui peut héberger des serveurs.
+
+[Pourquoi nous le construisons](https://simplex.chat/fr/why)
+
+## Financé par ses utilisateurs
+
+Pour rester indépendants, les grands canaux et les communautés paieront leurs propres serveurs.
+
+Et les utilisateurs peuvent désormais investir dans SimpleX Chat — le financement participatif est lancé !
+
+[Investir dans SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Feuille de route de SimpleX vers un Internet libre
+
+2026
+
+: Mise à l'échelle pour les grandes communautés
+
+Quitter les plateformes centralisées
+
+Juin 2027
+
+: Communautés et serveurs durables
+
+Lancement des Crédits Communautaires
+
+Déc 2027
+
+: Faites grandir vos communautés
+
+Outils pour promouvoir vos communautés
+
+[Groupe d'utilisateurs SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Rejoindre les communautés SimpleX
+
+Plus de 2 millions de personnes ont téléchargé les applications SimpleX.
+
+Trouvez vos chaînes et communautés dans l'annuaire et créez-en les vôtres !
+
+[Afficher l’annuaire SimpleX](https://simplex.chat/directory)
diff --git a/fr/invitation.md b/fr/invitation.md
new file mode 100644
index 0000000000..83d91ad89f
--- /dev/null
+++ b/fr/invitation.md
@@ -0,0 +1,66 @@
+# Vous avez reçu un lien unique pour vous connecter sur SimpleX Chat
+
+## Scannez le code QR avec l'application SimpleX Chat sur votre téléphone ou votre tablette.
+
+Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page — elles sont contenues dans le fragment de hachage de l'URL du lien.
+
+Vous n'avez pas encore téléchargé SimpleX Chat ?
+
+Utilisez les liens ci-dessous pour télécharger l'application.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scanner le code QR depuis l'application mobile
+
+# Vous avez reçu un lien unique pour vous connecter sur SimpleX Chat
+
+Pour établir une connexion :
+
+Installer l'application SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid)
+
+1
+
+Se connecter dans l'application
+
+Ouvrir l’application SimpleX
+
+2
+
+Appuyez sur le bouton « se connecter » dans l’application
+
+3
+
+## Scannez le code QR avec l'application SimpleX Chat
+
+Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page —
+elles sont contenus dans le fragment de hachage de l'URL du lien.
+
+## Installation de SimpleX Chat sur un terminal
+
+Utilisez cette commande :
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Voir SimpleX Chat Dépôt GitHub pour savoir comment télécharger ou compiler l’application à partir du code source.
+
+---
+
+## Si vous avez déjà installé SimpleX Chat pour le terminal
+
+Si vous avez déjà installé Chat SimpleX pour le terminal v1.0.0+, copiez la commande ci-dessous et utilisez-la dans le chat :
+
+## Rejoindre SimpleX
+
+Nous vous invitons à rejoindre la conversation
+
+[Rejoindre la communauté REDDIT](https://www.reddit.com/r/SimpleXChat/) [Rejoignez-nous sur GitHub](https://github.com/simplex-chat) [Faites un don ici pour nous aider](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Inscrivez-vous pour recevoir nos mises à jour
+
+---
+
+Obtenir SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fr/fdroid)
diff --git a/fr/invitation/index.html b/fr/invitation/index.html
index 989be4806b..d6128b0cfa 100644
--- a/fr/invitation/index.html
+++ b/fr/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Vous avez reçu un lien unique pour vous connecter sur SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scannez le code QR avec l'application SimpleX Chat sur votre téléphone ou votre tablette.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page — elles sont contenues dans le fragment de hachage de l'URL du lien.
+                Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page &mdash; elles sont contenues dans le fragment de hachage de l'URL du lien.
             </p>
             <p class="text-grey-black dark:text-white text-base">Vous n'avez pas encore téléchargé SimpleX Chat ?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Utilisez les liens ci-dessous pour télécharger l'application.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installer l'application SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Appuyez sur le bouton <span class="text-active-blue">«&nbsp;se connecter&nbsp;»</span> dans l’application</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Appuyez sur le bouton <span class="text-active-blue">« se connecter »</span> dans l’application</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scannez le code QR avec l'application SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page —<br> elles sont contenus dans le fragment de hachage de l'URL du lien.
+                            Les clés publiques et l'adresse de la file d'attente des messages dans ce lien NE sont PAS envoyées sur le réseau lorsque vous consultez cette page &mdash;<br> elles sont contenus dans le fragment de hachage de l'URL du lien.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installation de SimpleX Chat sur un terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Dépôt GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Si vous avez déjà installé SimpleX Chat pour le terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Inscrivez-vous pour recevoir nos mises à jour</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Entrez votre adresse e-mail">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtenir SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/messaging.md b/fr/messaging.md
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--- /dev/null
+++ b/fr/messaging.md
@@ -0,0 +1,253 @@
+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Pourquoi SimpleX est unique
+
+### Vous avez une confidentialité totale
+
+SimpleX protège la confidentialité de votre profil, de vos contacts et de vos métadonnées, en les cachant des serveurs du réseau SimpleX et de tout observateur.
+
+Contrairement à tout autre réseau de messagerie existant, SimpleX n'a aucun identifiant attribué aux utilisateurs — **pas même de nombres aléatoires**.
+
+### Vous êtes protégé contre les spams et les abus
+
+Parce que vous n'avez pas d'identifiant ou d'adresse fixe sur le réseau SimpleX, personne ne peut vous contacter sauf si vous partagez une adresse d'utilisateur unique ou temporaire, comme un code QR ou un lien.
+
+### Vous contrôlez vos données
+
+SimpleX stocke toutes les données utilisateur sur les appareils clients dans un **format de base de données chiffrée portable** — elles peuvent être transférées vers un autre appareil.
+
+Les messages chiffrés de bout en bout sont conservés temporairement sur les serveurs relais SimpleX jusqu'à leur réception, puis ils sont définitivement supprimés.
+
+### Vous possédez le réseau SimpleX
+
+Le réseau SimpleX est entièrement décentralisé et indépendant de toute crypto-monnaie ou de tout autre réseau, autre que l'Internet.
+
+Vous pouvez **utiliser SimpleX avec vos propres serveurs** ou avec les serveurs que nous fournissons — et toujours vous connecter à n'importe quel utilisateur.
+
+# Confidentialité totale de votre identité, profil, contacts et métadonnées
+
+Contrairement aux autres réseaux de messagerie, SimpleX n’attribue **aucun identifiant aux utilisateurs**. Il ne repose ni sur les numéros de téléphone, ni sur les adresses basées sur des domaines (comme les adresses e-mail ou XMPP), ni sur les noms d’utilisateur, les clés publiques ou même les nombres aléatoires pour identifier ses utilisateurs — les opérateurs des serveurs SimpleX ne savent pas combien de personnes utilisent leurs serveurs.
+
+Pour acheminer les messages, SimpleX utilise des [adresses anonymes distinctes pour chaque interlocuteur](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) de files de messages unidirectionnelles, séparées pour les messages reçus et envoyés, généralement via des serveurs différents.
+
+Cette conception protège la confidentialité des personnes avec lesquelles vous communiquez, en la cachant des serveurs de la plateforme SimpleX et de tout observateur. Pour cacher votre adresse IP aux serveurs, vous pouvez **vous connecter aux serveurs SimpleX via Tor**.
+
+# La meilleure protection contre le spam et les abus
+
+Parce que vous n'avez pas d'identifiant sur le SimpleX réseau, personne ne peut vous contacter sauf si vous partagez une adresse d'utilisateur unique ou temporaire, sous forme de code QR ou de lien .
+
+Même avec l'adresse utilisateur facultative, bien qu'elle puisse être utilisée pour envoyer des demandes de contact de spam, vous pouvez la modifier ou la supprimer complètement sans perdre aucune de vos connexions.
+
+# Propriété, contrôle et sécurité de vos données
+
+SimpleX Chat stocke toutes les données utilisateur uniquement sur les appareils clients à l'aide d'un **format de base de données chiffrée portable** qui peut être exporté et transféré vers n'importe quel appareil pris en charge .
+
+Les messages chiffrés de bout en bout sont conservés temporairement sur les serveurs relais SimpleX jusqu'à leur réception, puis ils sont définitivement supprimés.
+
+Contrairement aux serveurs de réseaux fédérés (e-mail, XMPP ou Matrix), les serveurs SimpleX ne stockent pas les comptes d'utilisateurs, ils ne font que relayer les messages, protégeant ainsi la vie privée des deux parties.
+
+Il n'y a pas d'identifiant ou de texte chiffré en commun entre le trafic serveur envoyé et reçu - si quelqu'un l'observe, il ne peut pas facilement déterminer qui communique avec qui, même si le TLS est compromis.
+
+# Entièrement décentralisé — les utilisateurs sont maîtres de leur réseau SimpleX
+
+Vous pouvez **utiliser SimpleX avec vos propres serveurs** et continuer à communiquer avec les personnes qui utilisent les serveurs préconfigurés dans les applications.
+
+Le réseau SimpleX utilise un [protocole ouvert](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) et fournit un [SDK pour créer des chatbots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), permettant de mettre en œuvre des services avec lesquels les utilisateurs peuvent interagir via les applications SimpleX Chat — nous avons hâte de voir quels services SimpleX vous allez créer.
+
+Si vous envisagez de développer pour le réseau SimpleX, par exemple un chatbot pour les utilisateurs de l’application SimpleX ou d’intégrer la bibliothèque SimpleX Chat à vos applications mobiles, n’hésitez pas à [nous contacter](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) pour obtenir des conseils et de l’aide.
+
+## Fonctionnalités
+
+Messages chiffrés E2E avec édition et format markdown
+
+Images, vidéos et fichiers
+chiffrés E2E
+
+Groupes chiffrés E2E décentralisés — où seuls les membres en connaissent l'existence
+
+Messages vocaux chiffrés E2E
+
+Conversations secrètes éphémères
+
+Appels audio et vidéo
+chiffrés E2E
+
+Stockage de l'app portable chiffré — déplacez votre profil vers un autre appareil
+
+Mode incognito —
+unique à SimpleX Chat
+
+## Ce qui rend SimpleX privé
+
+### Identifiants temporaires anonymes par paires
+
+SimpleX utilise des adresses et des informations d'identification anonymes temporaires par paires pour chaque contact utilisateur ou membre de groupe.
+
+Il permet la distribution des messages sans identifiants de profil utilisateur, offrant une meilleure confidentialité des métadonnées que les alternatives.
+
+### Échange de clés hors bande
+
+De nombreux réseaux de communication sont vulnérables aux attaques MITM par des serveurs ou des fournisseurs de réseau.
+
+Pour l'empêcher, les applications SimpleX transmettent des clés à usage unique hors bande, lorsque vous partagez une adresse sous forme de lien ou de code QR.
+
+### 2 couches de chiffrement de bout en bout
+
+Protocole à double ratchet —
+Messagerie OTR avec confidentialité persistante et récupération en cas d'effraction.
+
+Cryptobox NaCL dans chaque file d'attente pour empêcher toute corrélation de trafic entre les files d'attente de messages si le TLS est compromis.
+
+### Vérification de l'intégrité des messages
+
+Pour garantir l'intégrité, les messages sont numérotés séquentiellement et incluent le hachage du message précédent.
+
+Si un message est ajouté, supprimé ou modifié, le destinataire sera alerté.
+
+### Couche supplémentaire de chiffrement du serveur
+
+Couche supplémentaire de chiffrement du serveur pour la livraison au destinataire, afin d'empêcher la corrélation entre le trafic du serveur reçu et envoyé si le TLS est compromis.
+
+### Mélange de messages pour réduire la corrélation
+
+Les serveurs SimpleX agissent comme des nœuds de mixage à faible latence - les messages entrants et sortants ont un ordre différent.
+
+### Transport TLS sécurisé et authentifié
+
+Les connexions client-serveur ne sont établies qu'avec des algorithmes de chiffrement robustes et en TLS 1.2/1.3.
+
+L'empreinte du serveur et la fixation des canaux empêchent les attaques MITM et les attaques par rejeu.
+
+La reprise de connexion est désactivée pour empêcher les attaques de session.
+
+### Accès possible via Tor
+
+Pour protéger votre adresse IP, vous pouvez accéder aux serveurs via Tor ou un autre réseau de transport superposé.
+
+Pour utiliser SimpleX via Tor, veuillez installer [l'application Orbot](https://guardianproject.info/apps/org.torproject.android/) et activez le proxy SOCKS5 (ou le mode VPN [sur iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Files d'attente de messages unidirectionnelles
+
+Chaque file d'attente de messages transmet les messages dans une direction, avec des adresses d'envoi et de réception différentes.
+
+Il réduit les vecteurs d'attaque, par rapport aux agents de messagerie traditionnels, et les métadonnées disponibles.
+
+### Plusieurs couches de couverture de contenu
+
+SimpleX utilise une couverture de contenu pour chaque couche de chiffrement afin de résister aux attaques ciblant la taille des messages.
+
+Cela rend les messages de différentes tailles identiques pour les serveurs et les observateurs du réseau.
+
+## Réseau SimpleX
+
+SimpleX Chat offre la meilleure protection pour votre vie privée en combinant les avantages du P2P et des réseaux fédérés.
+
+### Contrairement aux réseaux P2P
+
+Tous les messages sont envoyés via les serveurs, offrant à la fois une meilleure protection des métadonnées et une livraison asynchrone fiable des messages, tout en évitant de nombreux .
+
+# Comparaison avec des protocoles de messagerie P2P
+
+Les applications et protocoles de messagerie [P2P](https://fr.wikipedia.org/wiki/Pair-%C3%A0-pair) présentent divers problèmes qui les rendent moins fiables que SimpleX, plus complexes à analyser et vulnérables à plusieurs types d'attaques.
+
+1. Les réseaux P2P s’appuient sur une variante de [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) pour acheminer les messages. Les architectures DHT doivent trouver un équilibre entre garantie de livraison et latence. SimpleX offre à la fois une meilleure garantie de livraison et une latence plus faible que les réseaux P2P, car le message peut être transmis de manière redondante via plusieurs serveurs en parallèle, en utilisant les serveurs choisis par le destinataire. Dans les réseaux P2P, le message est transmis séquentiellement via *O(log N)* nœuds, en utilisant des nœuds choisis par l’algorithme.
+2. Le modèle de SimpleX, contrairement à la plupart des réseaux P2P, n'a aucun identifiant utilisateur global d'aucune sorte, même temporaire, et n'utilise que des identifiants temporaires par paires, offrant un meilleur anonymat et une meilleure protection des métadonnées .
+3. Le P2P ne résout pas le problème des [attaques de type « man-in-the-middle »](https://fr.wikipedia.org/wiki/Attaque_de_l%27homme_du_milieu), et la plupart des implémentations existantes n’utilisent pas de messages hors bande pour l’échange initial de clés. SimpleX utilise des messages hors bande ou, dans certains cas, des connexions sécurisées et fiables préexistantes pour l’échange initial de clés.
+4. Les implémentations P2P peuvent être bloquées par certains fournisseurs d’accès à Internet (comme [BitTorrent](https://fr.wikipedia.org/wiki/BitTorrent)). SimpleX est indépendant du protocole de transport — il peut fonctionner via des protocoles web standards, par exemple les WebSockets.
+5. Tous les réseaux P2P connus peuvent être vulnérables aux [attaques Sybil](https://fr.wikipedia.org/wiki/Attaque_Sybil), car chaque nœud peut être découvert et le réseau fonctionne comme un tout. Les mesures connues pour les atténuer nécessitent soit un composant centralisé, soit une [preuve de travail](https://fr.wikipedia.org/wiki/Preuve_de_travail) coûteuse. Le réseau SimpleX ne permet pas de découvrir les serveurs, il est fragmenté et fonctionne comme plusieurs sous-réseaux isolés, ce qui rend les attaques à l’échelle du réseau impossibles.
+6. Les réseaux P2P peuvent être vulnérables aux [attaques DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), lorsque les clients peuvent retransmettre et amplifier le trafic, entraînant un déni de service à l’échelle du réseau. Les clients SimpleX ne relaient le trafic que depuis des connexions connues et ne peuvent pas être utilisés par un attaquant pour amplifier le trafic sur l’ensemble du réseau.
+
+---
+
+### Contrairement aux réseaux fédérés
+
+Les serveurs de relais SimpleX NE stockent PAS les profils d'utilisateurs, les contacts et les messages distribués, NE se connectent PAS les uns aux autres et il N'y a AUCUN répertoire de serveurs.
+
+---
+
+### Réseau SimpleX
+
+les serveurs fournissent des files d’attente unidirectionnelles pour connecter les utilisateurs, mais ils n’ont aucune visibilité sur le graphe des connexions du réseau — seuls les utilisateurs y ont accès.
+
+## SimpleX expliqué
+
+1. L'expérience des utilisateurs
+
+2. Comment ça marche
+
+3. Ce que voient les serveurs
+
+1. L'expérience des utilisateurs
+
+Vous pouvez créer des contacts et des groupes, et avoir des conversations bidirectionnelles, comme dans n'importe quelle autre messagerie.
+
+Comment cela peut-il fonctionner avec des files d'attente unidirectionnelles et sans identifiants de profil utilisateur ?
+
+2. Comment ça marche
+
+Pour chaque connexion, vous utilisez deux files d'attente de messages distinctes pour envoyer et recevoir des messages via des serveurs différents.
+
+Les serveurs ne transmettent les messages que dans une direction, sans connaître la totalité de la conversation ou des connexions de l'utilisateur.
+
+3. Ce que voient les serveurs
+
+Les serveurs disposent d'identifiants anonymes distincts pour chaque file d'attente, et ne savent pas à quels utilisateurs ils appartiennent.
+
+Les utilisateurs peuvent améliorer davantage leur protection de leurs métadonnées en utilisant Tor pour accéder aux serveurs, ce qui empêche la corrélation par adresse IP.
+
+## Comparaison avec d'autres protocoles
+
+|  |  | Signal, grandes plateformes | XMPP, Matrix | Protocoles P2P |
+| --- | --- | --- | --- | --- |
+| Identifiant global nécessaire | Non - privé | Oui [1] | Oui [2] | Oui [3] |
+| Risque d'attaque MITM | Non - sécurisé [4] | Oui [5] | Oui | Oui |
+| Dépendance au DNS | Non - résistant | Oui | Oui | Non |
+| Réseau unique ou centralisé | Non - décentralisé | Oui | Non - fédéré [6] | Oui [7] |
+| Attaque à l'échelle du réseau | Non - résistant | Oui | Oui [2] | Oui [8] |
+
+---
+
+1. Généralement basé sur un numéro de téléphone, dans certains cas sur des noms d'utilisateur
+2. Adresses basées sur le DNS
+3. Clé publique ou tout autre identifiant global unique
+4. Les relais SimpleX ne peuvent pas compromettre le chiffrement e2e. Vérifier le code de sécurité pour limiter les attaques sur le canal hors bande
+5. Si les serveurs de l’opérateur sont compromis. Vérifier le code de sécurité dans Signal et certaines autres applications pour limiter les risques
+6. Ne protège pas la confidentialité des métadonnées des utilisateurs
+7. Bien que les réseaux P2P soient distribués, ils ne sont pas fédérés — ils fonctionnent comme un réseau unique
+8. Les réseaux P2P ont soit une autorité centrale, soit l'ensemble du réseau peut être compromis — [voir ici](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparaison de la sécurité du chiffrement de bout en bout dans différentes applications de messagerie
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Remplissage des messages | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Dénégation (possibilité de nier) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Confidentialité persistante | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Sécurité après une compromission | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Échange de clés à deux facteurs | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Cryptographie hybride post-quantique | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar complète les messages à une taille arrondie à 1 024 octets, tandis que Signal les complète à 160 octets
+2. La répudiation ne concerne pas la connexion client-serveur.
+3. Il semblerait que l'utilisation de signatures cryptographiques compromette la possibilité de nier l'auteur (déni), mais cela doit être clarifié.
+4. La mise en œuvre multi-appareils compromet la sécurité post-compromission de Double Ratchet — [voir ici](https://eprint.iacr.org/2021/626.pdf).
+5. L'échange de clés à deux facteurs est facultatif et peut être remplacé par une vérification par code de sécurité.
+6. L’accord de clés post-quantique est « épars » — il ne protège que certaines des étapes du ratchet.
diff --git a/fr/messaging/index.html b/fr/messaging/index.html
index 3cb0e1f0e1..45d6200702 100644
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous avez une confidentialité totale</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous êtes protégé<br>contre les spams et les abus</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous contrôlez vos données</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous possédez le réseau SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Il permet la distribution des messages sans identifiants de profil utilisateur, offrant une meilleure confidentialité des métadonnées que les alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
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@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pour l'empêcher, les applications SimpleX transmettent des clés à usage unique hors bande, lorsque vous partagez une adresse sous forme de lien ou de code QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Cryptobox NaCL dans chaque file d'attente pour empêcher toute corrélation de trafic entre les files d'attente de messages si le TLS est compromis.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Si un message est ajouté, supprimé ou modifié, le destinataire sera alerté.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Couche supplémentaire de chiffrement du serveur pour la livraison au destinataire, afin d'empêcher la corrélation entre le trafic du serveur reçu et envoyé si le TLS est compromis.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Les serveurs SimpleX agissent comme des nœuds de mixage à faible latence - les messages entrants et sortants ont un ordre différent.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">La reprise de connexion est désactivée pour empêcher les attaques de session.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pour utiliser SimpleX via Tor, veuillez installer <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">l'application Orbot</a> et activez le proxy SOCKS5 (ou le mode VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank"> sur iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Il réduit les vecteurs d'attaque, par rapport aux agents de messagerie traditionnels, et les métadonnées disponibles.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Cela rend les messages de différentes tailles identiques pour les serveurs et les observateurs du réseau.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Appuyez pour fermer</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
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+<link rel="describedby" href="/llms.txt"/>
+
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous avez une confidentialité totale</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous êtes protégé<br>contre les spams et les abus</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous contrôlez vos données</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Vous possédez le réseau SimpleX</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
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-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/fr/why.md b/fr/why.md
new file mode 100644
index 0000000000..3b555e0637
--- /dev/null
+++ b/fr/why.md
@@ -0,0 +1,19 @@
+# Vous êtes né sans compte.
+
+Personne ne surveillait vos conversations. Personne ne dressait de carte des endroits où vous étiez allés. La vie privée n’était pas une fonctionnalité, c’était un mode de vie.
+
+Puis nous sommes passés au numérique, et chaque plateforme nous demandait de lui livrer une partie de nous-mêmes : notre nom, notre numéro, nos amis. Nous avons accepté que le prix à payer pour communiquer avec les autres soit de révéler à qui nous parlions. À chaque génération, tant sur le plan humain que technologique, cela s'est passé ainsi : le téléphone, les e-mails, les messageries instantanées, les réseaux sociaux. Cela semblait être la seule voie possible.
+
+Il existe une autre solution. Un réseau sans numéros de téléphone, sans noms d'utilisateur, sans comptes, sans aucune forme d'identité d'utilisateur. Un réseau qui met les gens en relation et transmet des messages cryptés sans que l'on sache qui est connecté.
+
+Ça n’est pas une meilleure serrure sur la porte de quelqu’un d’autre. Ça n’est pas un propriétaire plus aimable qui respecte votre vie privée, mais qui tient tout de même un registre de tous les visiteurs. Vous n’êtes pas un invité, vous êtes chez vous. Aucun roi ne peut y entrer : c’est vous le souverain.
+
+Vos conversations vous appartiennent, comme avant Internet. Le réseau n’est pas un lieu que vous visitez. C’est un espace que vous créez et possédez. Et personne ne peut vous le prendre, que vous le gardiez privé ou public.
+
+La plus ancienne des libertés humaines — parler à une autre personne sans être surveillé — bâtie sur une infrastructure qui ne peut pas la trahir.
+
+Parce que nous avons détruit le pouvoir de savoir qui vous êtes. Afin que *votre* pouvoir ne puisse jamais vous être enlevé.
+
+Soyez libre dans votre réseau.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/fr/why/index.html b/fr/why/index.html
index 939ed67580..5b4c5a2899 100644
--- a/fr/why/index.html
+++ b/fr/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/fr/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Soyez libre dans votre réseau.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/he/contact.md b/he/contact.md
new file mode 100644
index 0000000000..cc27f992a3
--- /dev/null
+++ b/he/contact.md
@@ -0,0 +1,66 @@
+# קיבלת כתובת להתחבר ב-SimpleX Chat
+
+## סרקו את קוד ה-QR עם אפליקציית SimpleX Chat בטלפון או בטאבלט שלכם.
+
+המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה — הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+
+עדיין לא הורדתם את ה-SimpleX Chat?
+
+השתמשו בקישורים למטה כדי להוריד את האפליקציה.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+סרקו קוד QR באפליקציה לנייד
+
+# קיבלת כתובת להתחבר ב-SimpleX Chat
+
+כדי ליצור חיבור:
+
+התקינו את אפליקציית SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid)
+
+1
+
+התחברו באפליקציה
+
+פתחו את אפליקציית Simplex
+
+2
+
+הקישו על הלחצן 'התחבר' באפליקציה
+
+3
+
+## סרקו את קוד ה-QR באפליקציית SimpleX Chat
+
+המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה —
+הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+
+## התקנת SimpleX Chat למסוף שורת הפקודה
+
+השתמשו בפקודה הזו:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+ראו SimpleX Chat מאגר GitHub לקבלת ההוראות כיצד להוריד או לקמפל אותו מקוד המקור.
+
+---
+
+## אם כבר התקנתם את SimpleX Chat עבור מסוף שורת הפקודה
+
+אם כבר התקנתם SimpleX Chat עבור מסוף שורת הפקודה v1.0.0+, העתיקו את הפקודה למטה והשתמש בה בצ'אט:
+
+## הצטרפו SimpleX
+
+אנו מזמינים אתכם להצטרף לשיחה
+
+[הצטרפו לקהילת REDDIT](https://www.reddit.com/r/SimpleXChat/) [הצטרפו אלינו ב-GitHub](https://github.com/simplex-chat) [תרמו כאן כדי לעזור לנו](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+הירשמו כדי לקבל את העדכונים שלנו
+
+---
+
+הורידו את [אפליקציית שולחן העבודה](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid)
diff --git a/he/contact/index.html b/he/contact/index.html
index 101ca15c44..5a60331552 100644
--- a/he/contact/index.html
+++ b/he/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">קיבלת כתובת להתחבר ב-SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">סרקו את קוד ה-QR עם אפליקציית SimpleX Chat בטלפון או בטאבלט שלכם.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה — הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+                המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה &mdash; הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
             </p>
             <p class="text-grey-black dark:text-white text-base">עדיין לא הורדתם את ה-SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">השתמשו בקישורים למטה כדי להוריד את האפליקציה.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">התקינו את אפליקציית SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">הקישו על הלחצן <span class="text-active-blue">'התחבר'</span> באפליקציה</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">הקישו על הלחצן <span class='text-active-blue'>'התחבר'</span> באפליקציה</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">סרקו את קוד ה-QR באפליקציית SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה —<br> הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+                            המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה &mdash;<br> הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">התקנת SimpleX Chat למסוף שורת הפקודה</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">מאגר GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">אם כבר התקנתם את SimpleX Chat עבור מסוף שורת הפקודה</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">הירשמו כדי לקבל את העדכונים שלנו</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
-            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא" ל="" שלכם"="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
+            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא"ל שלכם">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">הורידו את <a href="/downloads">אפליקציית שולחן העבודה</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/fdroid.md b/he/fdroid.md
new file mode 100644
index 0000000000..9425bd919e
--- /dev/null
+++ b/he/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat דרך F-Droid
+
+### מאגר SimpleX Chat
+
+גרסאות יציבות ובטא שנבנו על ידי המפתחים
+
+כדי להוסיף אותו ללקוח F-Droid שלכם, סרקו את קוד ה-QR או השתמשו בכתובת האתר הזו:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+חתימת מפתח טביעת אצבע (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### מאגר F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+גרסאות יציבות שנבנו על ידי F-Droid.org
+
+גרסאות למאגר זה משוחררות לאחר כמה ימים.
+
+מאגרי SimpleX Chat ו-F-Droid.org חותמים על גרסאות עם מפתחות שונים. כדי לעבור, אנא [ייצא](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) את מסד הנתונים של הצ'אט והתקן מחדש את האפליקציה.
diff --git a/he/fdroid/index.html b/he/fdroid/index.html
index 213c58e06f..b3a6264594 100644
--- a/he/fdroid/index.html
+++ b/he/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat דרך F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">גרסאות יציבות ובטא שנבנו על ידי המפתחים</p>
-                        <p>כדי להוסיף אותו ללקוח F-Droid שלכם, <span class="hide-on-mobile">סרקו את קוד ה-QR או</span> השתמשו בכתובת האתר הזו:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>כדי להוסיף אותו ללקוח F-Droid שלכם, <span class='hide-on-mobile'>סרקו את קוד ה-QR או</span> השתמשו בכתובת האתר הזו:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             חתימת מפתח טביעת אצבע (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">מאגר F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">גרסאות יציבות שנבנו על ידי F-Droid.org</p>
                 <p class="mb-2">גרסאות למאגר זה משוחררות לאחר כמה ימים.</p>
-                <p class="mb-2">מאגרי SimpleX Chat ו-F-Droid.org חותמים על גרסאות עם מפתחות שונים. כדי לעבור, אנא <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">ייצא</a> את מסד הנתונים של הצ'אט והתקן מחדש את האפליקציה.</p>
+                <p class="mb-2">מאגרי SimpleX Chat ו-F-Droid.org חותמים על גרסאות עם מפתחות שונים. כדי לעבור, אנא <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>ייצא</a> את מסד הנתונים של הצ'אט והתקן מחדש את האפליקציה.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/file.md b/he/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/he/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/he/file/index.html b/he/file/index.html
index 56253bcf66..adf5a7bafb 100644
--- a/he/file/index.html
+++ b/he/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/index.html b/he/index.html
index 85975bd5d1..e7df9e9f16 100644
--- a/he/index.html
+++ b/he/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/he/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/he/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/he/index.md b/he/index.md
new file mode 100644
index 0000000000..174f8df3f1
--- /dev/null
+++ b/he/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [למדו עוד.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/he/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/he/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/he/why)
+
+## ממומן על ידי המשתמשים
+
+כדי להישאר עצמאיים, ערוצים וקהילות גדולים ישלמו עבור השרתים שלהם.
+
+וכעת המשתמשים יכולים להשקיע ב-SimpleX Chat — מימון ההמונים פעיל!
+
+[השקיעו ב-SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/he/invitation.md b/he/invitation.md
new file mode 100644
index 0000000000..a01900156c
--- /dev/null
+++ b/he/invitation.md
@@ -0,0 +1,66 @@
+# קיבלת קישור חד-פעמי להתחבר ב-SimpleX Chat
+
+## סרקו את קוד ה-QR עם אפליקציית SimpleX Chat בטלפון או בטאבלט שלכם.
+
+המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה — הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+
+עדיין לא הורדתם את ה-SimpleX Chat?
+
+השתמשו בקישורים למטה כדי להוריד את האפליקציה.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+סרקו קוד QR באפליקציה לנייד
+
+# קיבלת קישור חד-פעמי להתחבר ב-SimpleX Chat
+
+כדי ליצור חיבור:
+
+התקינו את אפליקציית SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid)
+
+1
+
+התחברו באפליקציה
+
+פתחו את אפליקציית Simplex
+
+2
+
+הקישו על הלחצן 'התחבר' באפליקציה
+
+3
+
+## סרקו את קוד ה-QR באפליקציית SimpleX Chat
+
+המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה —
+הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+
+## התקנת SimpleX Chat למסוף שורת הפקודה
+
+השתמשו בפקודה הזו:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+ראו SimpleX Chat מאגר GitHub לקבלת ההוראות כיצד להוריד או לקמפל אותו מקוד המקור.
+
+---
+
+## אם כבר התקנתם את SimpleX Chat עבור מסוף שורת הפקודה
+
+אם כבר התקנתם SimpleX Chat עבור מסוף שורת הפקודה v1.0.0+, העתיקו את הפקודה למטה והשתמש בה בצ'אט:
+
+## הצטרפו SimpleX
+
+אנו מזמינים אתכם להצטרף לשיחה
+
+[הצטרפו לקהילת REDDIT](https://www.reddit.com/r/SimpleXChat/) [הצטרפו אלינו ב-GitHub](https://github.com/simplex-chat) [תרמו כאן כדי לעזור לנו](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+הירשמו כדי לקבל את העדכונים שלנו
+
+---
+
+הורידו את [אפליקציית שולחן העבודה](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/he/fdroid)
diff --git a/he/invitation/index.html b/he/invitation/index.html
index b1d5184895..d9ed6e2472 100644
--- a/he/invitation/index.html
+++ b/he/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">קיבלת קישור חד-פעמי להתחבר ב-SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">סרקו את קוד ה-QR עם אפליקציית SimpleX Chat בטלפון או בטאבלט שלכם.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה — הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+                המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה &mdash; הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
             </p>
             <p class="text-grey-black dark:text-white text-base">עדיין לא הורדתם את ה-SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">השתמשו בקישורים למטה כדי להוריד את האפליקציה.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">התקינו את אפליקציית SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">הקישו על הלחצן <span class="text-active-blue">'התחבר'</span> באפליקציה</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">הקישו על הלחצן <span class='text-active-blue'>'התחבר'</span> באפליקציה</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">סרקו את קוד ה-QR באפליקציית SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה —<br> הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
+                            המפתחות הציבוריים וכתובת תור ההודעות בקישור זה אינם נשלחים דרך הרשת כאשר אתם צופים בדף זה &mdash;<br> הם כלולים בקטע הגיבוב (hash) של כתובת הקישור.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">התקנת SimpleX Chat למסוף שורת הפקודה</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">מאגר GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">אם כבר התקנתם את SimpleX Chat עבור מסוף שורת הפקודה</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">הירשמו כדי לקבל את העדכונים שלנו</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
-            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא" ל="" שלכם"="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
+            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא"ל שלכם">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">הורידו את <a href="/downloads">אפליקציית שולחן העבודה</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/messaging.md b/he/messaging.md
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--- /dev/null
+++ b/he/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## מדוע SimpleX הוא ייחודי
+
+### יש לך פרטיות מלאה
+
+SimpleX מגן על פרטיות הפרופיל, אנשי הקשר והמטא נתונים שלכם, מסתיר אותם משרתי רשת SimpleX ומכל צופה.
+
+בניגוד לכל רשת הודעות קיימת אחרת, ל-SimpleX אין מזהים המשויכים למשתמשים — **אפילו לא מספרים אקראיים**.
+
+### אתה מוגן מפני ספאם וניצול לרעה
+
+מכיוון שאין לך מזהה או כתובת קבועה ברשת SimpleX, אף אחד לא יכול ליצור איתך קשר אלא אם כן אתה משתף כתובת משתמש חד-פעמית או זמנית, כקוד QR או קישור.
+
+### אתה שולט בנתונים שלך
+
+SimpleX מאחסן את כל נתוני המשתמש במכשירי הלקוח ב**פורמט מסד נתונים מוצפן נייד** — ניתן להעביר אותו למכשיר אחר.
+
+ההודעות המוצפנות מקצה לקצה מוחזקות באופן זמני בשרתי ממסר של SimpleX עד שמתקבלות, ואז הן נמחקות לצמיתות.
+
+### רשת SimpleX בבעלותך
+
+רשת SimpleX מבוזרת לחלוטין ואינה תלויה בכל מטבע קריפטוגרפי או בכל רשת אחרת, מלבד האינטרנט.
+
+אתם יכולים **להשתמש ב-SimpleX עם השרתים שלכם** או עם השרתים שסופקו על ידינו — ועדיין להתחבר לכל משתמש.
+
+# פרטיות מלאה של הזהות, הפרופיל, אנשי הקשר והמטא נתונים שלך
+
+בניגוד לרשתות הודעות אחרות, ב-SimpleX **אין מזהים המשויכים למשתמשים**. אנחנו לא מסתמכים על מספרי טלפון, כתובות מבוססות דומיין (כמו אימייל או XMPP), שמות משתמש, מפתחות ציבוריים או אפילו מספרים אקראיים כדי לזהות את המשתמשים שלנו — מפעילי שרתי SimpleX אינם יודעים כמה אנשים משתמשים בשרתים שלהם.
+
+כדי להעביר הודעות, SimpleX משתמשת ב-[כתובות אנונימיות זוגיות](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) של תורי הודעות חד-כיווניים, נפרדים להודעות נכנסות ויוצאות, בדרך כלל דרך שרתים שונים.
+
+עיצוב זה מגן על הפרטיות של מי שאתה מתקשר איתו, מסתיר אותה משרתי רשת SimpleX ומכל צופה. כדי להסתיר את כתובת ה-IP שלך מהשרתים, אתה יכול**להתחבר לשרתי SimpleX באמצעות Tor**.
+
+# ההגנה הטובה ביותר מפני ספאם וניצול לרעה
+
+מכיוון שברשת SimpleX אין לכם מזהים, אף אחד לא יכול ליצור איתכם קשר אלא אם כן אתם משתפים כתובת משתמש חד פעמית או זמנית, כקוד QR או קישור.
+
+אפילו עם כתובת המשתמש האופציונלית, בעוד שניתן להשתמש בה לשליחת בקשות ליצירת קשר דואר זבל, אתה יכול לשנות או למחוק אותה לחלוטין מבלי לאבד אף אחד מהחיבורים שלך.
+
+# בעלות, שליטה ואבטחה של הנתונים שלך
+
+SimpleX Chat מאחסן את כל נתוני המשתמש רק במכשירי הלקוח באמצעות **פורמט מסד נתונים מוצפן נייד** שניתן לייצא ולהעביר לכל מכשיר נתמך.
+
+ההודעות המוצפנות מקצה לקצה מוחזקות באופן זמני בשרתי ממסר של SimpleX עד שמתקבלות, ואז הן נמחקות לצמיתות.
+
+שלא כמו שרתי רשת מאוחדים (דוא"ל, XMPP או Matrix), שרתי SimpleX אינם מאחסנים חשבונות משתמשים, הם רק מעבירים הודעות, ומגנים על הפרטיות של שני הצדדים.
+
+אין מזהים או טקסט מוצפן משותף בין תעבורת שרת שנשלחה ומתקבלת — אם מישהו צופה בזה, הם לא יכולים לקבוע בקלות מי מתקשר עם מי, גם אם ה-TLS נפרץ.
+
+# מבוזר לחלוטין — המשתמשים הם הבעלים של רשת SimpleX
+
+ניתן **להשתמש ב-SimpleX עם השרתים שלכם** ועדיין לתקשר עם אנשים המשתמשים בשרתים שתצורתם נקבעה מראש באפליקציות.
+
+רשת SimpleX משתמשת ב[פרוטוקול פתוח](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) ומספקת [SDK ליצירת צ'אט בוטים](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), המאפשר הטמעה של שירותים שמשתמשים יכולים לתקשר איתם באמצעות אפליקציות SimpleX Chat — אנחנו ממש מצפים לראות אילו שירותי SimpleX אתם יכולים לבנות.
+
+אם אתם שוקלים לפתח עבור רשת SimpleX, למשל, את הצ'אט בוט עבור משתמשי אפליקציית SimpleX, או שילוב של ספריית SimpleX Chat באפליקציות לנייד שלכם, אנא [צרו קשר](https://simplex.chat/contact#%20/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JB38MZG9NLUZ_8JB38t%2ADKeAyGeee%208mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) לכל עצה ותמיכה.
+
+## מאפיינים
+
+הודעות מוצפנות מקצה לקצה עם סימונים ואפשרויות עריכה
+
+תמונות, וידאו וקבצים
+בהצפנת קצה-אל-קצה
+
+קבוצות סודיות מבוזרות —
+רק המשתמשים יודעים שהן קיימות
+
+הודעות קוליות מוצפנות מקצה לקצה
+
+הודעות נעלמות
+
+שיחות שמע ווידאו
+מוצפנות מקצה לקצה
+
+מסד נתונים מוצפן נייד — העבר פרופיל למכשיר אחר
+
+מצב זהות נסתרת —
+ייחודי ל-SimpleX Chat
+
+## מה הופך את SimpleX לפרטי
+
+### מזהים זמניים אנונימיים בזוגות
+
+SimpleX משתמש בכתובות ואישורים אנונימיים זמניים בזוגות עבור כל איש קשר של משתמש או חבר בקבוצה.
+
+זה מאפשר להעביר הודעות ללא מזהי פרופיל משתמש, ומספק פרטיות מטא-נתונים טובה יותר מאשר חלופות אחרות.
+
+### החלפת מפתחות מחוץ לרשת
+
+רשתות תקשורת רבות פגיעות להתקפות MITM על ידי שרתים או ספקי רשת.
+
+כדי למנוע זאת, אפליקציות SimpleX מעבירות מפתחות חד-פעמיים מחוץ לפס, כאשר אתם משתפים כתובת כקישור או כקוד QR.
+
+### 2 שכבות של הצפנה מקצה לקצה
+
+פרוטוקול ראצ'ט כפול —
+העברת הודעות OTR עם סודיות מושלמת קדימה ושחזור פריצה.
+
+תיבת הצפנה NaCL בכל תור כדי למנוע קורלציית תעבורה בין תורי הודעות במקרה שאבטחת TLS נפגעה.
+
+### בדיקת תקינות ההודעה
+
+על מנת להבטיח את שלמות ההודעות, הן ממוספרות ברצף וכוללות את הגיבוב (hash) של ההודעה הקודמת.
+
+אם הודעה כלשהי תתווסף, תוסר או תשתנה, הנמען יקבל התראה.
+
+### שכבה נוספת של הצפנת שרת
+
+שכבה נוספת של הצפנת שרת למסירה לנמען, כדי למנוע קורלציה בין תעבורת השרת המתקבלת ונשלחת במקרה שאבטחת TLS נפגעה.
+
+### ערבוב הודעות לשם הפחתת קורלציה
+
+שרתי SimpleX פועלים כצמתי ערבוב עם זמן השהיה נמוך — להודעות הנכנסות והיוצאות יש סדר שונה.
+
+### תעבורת TLS מאובטחת ומאומתת
+
+עבור חיבורי שרת-לקוח, נעשה שימוש רק ב-TLS 1.2/1.3 עם אלגוריתמים חזקים.
+
+טביעת אצבע של שרת ואיגוד ערוצים מונעים התקפת אדם בתווך (MITM) והתקפת שליחה מחדש (Replay attack).
+
+חידוש החיבור מושבת כדי למנוע התקפות הפעלה.
+
+### אופציונלי גישה דרך Tor
+
+כדי להגן על כתובת ה-IP שלכם, אתם יכולים לגשת לשרתים דרך Tor או רשת שכבת-על אחרת של תעבורה.
+
+כדי להשתמש ב-SimpleX דרך Tor, התקן את [אפליקציית Orbot](https://guardianproject.info/apps/org.torproject.android/) והפעל את SOCKS5 proxy (או VPN [ב-iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### תורי הודעות חד-כיווניים
+
+כל תור הודעות מעביר הודעות בכיוון אחד, עם כתובות השליחה והקבלה השונות.
+
+זה מפחית את וקטורי ההתקפה, בהשוואה למתווכי הודעות מסורתיים, ואת המטא-נתונים הזמינים.
+
+### שכבות מרובות של ריפוד תוכן
+
+SimpleX משתמש בריווח התוכן עבור כל שכבת הצפנה כדי לסכל התקפות על גודל הודעה.
+
+זה גורם להודעות בגדלים שונים להיראות זהים לשרתים ולמשקיפים ברשת.
+
+## רשת SimpleX
+
+SimpleX Chat מספק את הפרטיות הטובה ביותר על ידי שילוב היתרונות של P2P ורשתות מאוחדות.
+
+### בניגוד לרשתות P2P
+
+כל ההודעות נשלחות דרך השרתים, שמספקים פרטיות טובה יותר של מטא נתונים וגם מסירת הודעות אסינכרונית אמינה, תוך הימנעות מהרבה .
+
+# השוואה לפרוטוקולי העברת הודעות P2P
+
+לפרוטוקולי הודעות ואפליקציות [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) יש בעיות שונות שהופכות אותן לפחות אמינות מ-SimpleX, מורכבות יותר לניתוח, ופגיעות למספר סוגי התקפות.
+
+1. רשתות P2P מסתמכות על גרסה כלשהי של [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) כדי לנתב הודעות. עיצובי DHT צריכים לאזן בין אחריות מסירה לבין זמן השהיה. ל- SimpleX יש גם אחריות מסירה טובה יותר וגם השהיה נמוכה יותר מאשר P2P, מכיוון שניתן להעביר את ההודעה כיתירות דרך מספר שרתים במקביל, באמצעות השרתים שנבחרו על ידי הנמען. ברשתות P2P ההודעה מועברת דרך *O(log N)* צמתים ברצף, תוך שימוש בצמתים שנבחרו על ידי האלגוריתם.
+2. לעיצוב של SimpleX, בניגוד לרוב רשתות ה-P2P, אין מזהי משתמש גלובלי מכל סוג שהוא, אפילו זמני, והוא משתמש רק במזהים זמניים זוגיים, המספקים אנונימיות טובה יותר והגנה על מטא נתונים.
+3. P2P אינו פותר את בעיית [התקפת MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack), ורוב ההטמעות הקיימות אינן משתמשות בהודעות out-of-band עבור החלפת המפתחות הראשונית. SimpleX משתמש בהודעות out-of-band או, במקרים מסוימים, בחיבורים מאובטחים ומהימנים קיימים מראש לצורך החלפת המפתחות הראשונית.
+4. יישומי P2P עלולים להיחסם על ידי ספקי אינטרנט מסוימים (כמו [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX אינו תלוי בתעבורה - הוא יכול לעבוד על פרוטוקולי אינטרנט סטנדרטיים, למשל WebSockets.
+5. כל רשתות ה-P2P המוכרות עשויות להיות פגיעות ל[התקפת Sybil](https://en.wikipedia.org/wiki/Sybil_attack), מכיוון שכל צומת ניתן לגילוי, והרשת פועלת כמכלול. אמצעים ידועים כדי למתן את זה דורשים רכיב ריכוזי או [מערכת הוכחת עבודה](https://en.wikipedia.org/wiki/Proof_of_work) יקרה. לרשת SimpleX אין יכולת גילוי של שרת, היא מפוצלת ופועלת כמספר תת-רשתות מבודדות, מה שהופך התקפות ברחבי הרשת לבלתי אפשריות.
+6. רשתות P2P עשויות להיות פגיעות ל[התקפת DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) , כאשר הלקוחות יכולים לשדר מחדש ולהגביר את התעבורה, וכתוצאה מכך מניעת שירות בכל הרשת. לקוחות SimpleX מעבירים רק תעבורה מחיבור ידוע ואינם יכולים להיות בשימוש על ידי תוקף כדי להגביר את התעבורה בכל הרשת.
+
+---
+
+### בניגוד לרשתות מאוחדות
+
+שרתי ממסר SimpleX אינם מאחסנים פרופילי משתמש, אנשי קשר והודעות שנמסרו, אינם מתחברים זה לזה, ואין ספריית שרתים.
+
+---
+
+### רשת SimpleX
+
+השרתים מספקים תורים חד-כיווניים לחיבור המשתמשים, אך הם לא יכול לראות את גרף חיבור הרשת — רק המשתמשים יכולים לראות זאת.
+
+## תיאור SimpleX
+
+1. חוויית משתמש
+
+2. איך זה עובד
+
+3. מה השרתים רואים
+
+1. חוויית משתמש
+
+אתם יכולים ליצור אנשי קשר וקבוצות, ולנהל שיחות דו-כיווניות, כמו בכל תוכנה אחרת לשליחת הודעות.
+
+איך זה יכול לעבוד עם תורים חד-כיווניים וללא מזהי פרופיל משתמש?
+
+2. איך זה עובד
+
+עבור כל חיבור, שני תורי העברת הודעות נפרדים משמשים לשליחה וקבלה של הודעות דרך שרתים שונים.
+
+שרתים מעבירים הודעות רק בכיוון אחד, מבלי לקבל את התמונה המלאה של השיחות או החיבורים של המשתמש.
+
+3. מה השרתים רואים
+
+לשרתים יש אישורים אנונימיים נפרדים לכל תור, ואינם יודעים לאילו משתמשים הם שייכים.
+
+משתמשים יכולים לשפר עוד יותר את פרטיות המטא-נתונים על ידי שימוש ב- Tor כדי לגשת לשרתים, ולמנוע קורלציה לפי כתובת IP.
+
+## השוואה לפרוטוקולים אחרים
+
+|  |  | Signal, פלטפורמות גדולות | XMPP, Matrix | פרוטוקולי P2P |
+| --- | --- | --- | --- | --- |
+| דורש זהות גלובלית | לא - פרטי | כן [1] | כן [2] | כן [3] |
+| אפשרות של התקפת MITM | לא - מאובטח [4] | כן [5] | כן | כן |
+| תלות ב-DNS | לא - גמיש | כן | כן | לא |
+| רשת בודדת או מרכזית | לא - מבוזר | כן | לא - פדרלית [6] | כן [7] |
+| רכיב מרכזי או מתקפת רשת רחבה | לא - גמיש | כן | כן [2] | כן [8] |
+
+---
+
+1. בדרך כלל מבוססת על מספר טלפון, במקרים מסוימים על שמות משתמש
+2. כתובות מבוססות DNS
+3. מפתח ציבורי או מזהה ייחודי גלובלי אחר
+4. ממסרי SimpleX אינם יכולים לסכן הצפנה מקצה לקצה. ודא קוד אבטחה כדי לצמצם התקפות על ערוץ "מחוץ לרשת"
+5. אם השרתי המפעיל נפגעים. אמת את קוד האבטחה ב-Signal ובכמה אפליקציות אחרות כדי למתן את זה
+6. אינו מגן על פרטיות המטא נתונים של המשתמשים
+7. בעוד שרשתות עמית לעמית (P2P) מבוזרות, הן אינן מאוחדות (פדרטיביות) — הן פועלות כרשת יחידה
+8. לרשתות P2P יש רשות מרכזית או שכל הרשת יכולה להיפגע — [ראו כאן](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [ראו כאן](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/he/messaging/index.html b/he/messaging/index.html
index 0016a8e32b..7f9337a9b9 100644
--- a/he/messaging/index.html
+++ b/he/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">יש לך פרטיות מלאה</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">אתה מוגן<br>מפני ספאם וניצול לרעה</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">אתה שולט בנתונים שלך</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">רשת SimpleX בבעלותך</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">זה מאפשר להעביר הודעות ללא מזהי פרופיל משתמש, ומספק פרטיות מטא-נתונים טובה יותר מאשר חלופות אחרות.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">כדי למנוע זאת, אפליקציות SimpleX מעבירות מפתחות חד-פעמיים מחוץ לפס, כאשר אתם משתפים כתובת כקישור או כקוד QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">תיבת הצפנה NaCL בכל תור כדי למנוע קורלציית תעבורה בין תורי הודעות במקרה שאבטחת TLS נפגעה.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">אם הודעה כלשהי תתווסף, תוסר או תשתנה, הנמען יקבל התראה.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">שכבה נוספת של הצפנת שרת למסירה לנמען, כדי למנוע קורלציה בין תעבורת השרת המתקבלת ונשלחת במקרה שאבטחת TLS נפגעה.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">שרתי SimpleX פועלים כצמתי ערבוב עם זמן השהיה נמוך — להודעות הנכנסות והיוצאות יש סדר שונה.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">חידוש החיבור מושבת כדי למנוע התקפות הפעלה.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">כדי להשתמש ב-SimpleX דרך Tor, התקן את <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">אפליקציית Orbot</a> והפעל את SOCKS5 proxy (או VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">ב-iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">זה מפחית את וקטורי ההתקפה, בהשוואה למתווכי הודעות מסורתיים, ואת המטא-נתונים הזמינים.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">זה גורם להודעות בגדלים שונים להיראות זהים לשרתים ולמשקיפים ברשת.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/old/index.html b/he/old/index.html
index ba176437c8..75488b03cb 100644
--- a/he/old/index.html
+++ b/he/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">פרטיות מוגדרת מחדש</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -752,16 +757,16 @@ window.addEventListener('click',(e)=>{
     כדי להעביר הודעות, במקום מזהי משתמש המשמשים את כל הרשתות האחרות, SimpleX משתמש במזהים זמניים אנונימיים של תורי הודעות, נפרדים לכל אחד מהחיבורים שלך - אין מזהים ארוכי טווח.
 </p>
 <p>
-    אתה מגדיר באילו שרתים להשתמש כדי לקבל את ההודעות, אנשי הקשר שלך — השרתים שבהם אתה משתמש כדי לשלוח את ההודעות אליהם. סביר שכל שיחה תהשתמש בשני שרתים שונים.
+    אתה מגדיר באילו שרתים להשתמש כדי לקבל את ההודעות, אנשי הקשר שלך &mdash; השרתים שבהם אתה משתמש כדי לשלוח את ההודעות אליהם. סביר שכל שיחה תהשתמש בשני שרתים שונים.
 </p>
 <p>
-    עיצוב זה מונע דליפה כלשהי של משתמשים' מטא נתונים ברמת האפליקציה. כדי לשפר עוד יותר את הפרטיות ולהגן על כתובת ה-IP שלך, תוכל להתחבר לשרתי הודעות באמצעות Tor.
+    עיצוב זה מונע דליפה כלשהי של משתמשים&apos; מטא נתונים ברמת האפליקציה. כדי לשפר עוד יותר את הפרטיות ולהגן על כתובת ה-IP שלך, תוכל להתחבר לשרתי הודעות באמצעות Tor.
 </p>
 <p>
     רק מכשירי לקוח מאחסנים פרופילי משתמשים, אנשי קשר וקבוצות; ההודעות נשלחות עם הצפנה דו-שכבתית מקצה לקצה.
 </p>
 <p>
-    קרא עוד ב<a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">סקירה הטכנית של SimpleX</a>.
+    קרא עוד ב<a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>סקירה הטכנית של SimpleX</a>.
 </p>
                         </div>
                     </div>
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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         </div>
     </div>
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">הורידו את <a href="/downloads">אפליקציית שולחן העבודה</a> SimpleX</p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -931,8 +936,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">מדוע פרטיות <span class="gradient-text">חשובה</span></h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">שמירה על פרטיות המטא נתונים שלכם — <span class="text-active-blue">עם מי אתם מדברים</span> — מגנה עליכם מפני:</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">מדוע פרטיות <span class='gradient-text'>חשובה</span></h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">שמירה על פרטיות המטא נתונים שלכם &mdash; <span class='text-active-blue'>עם מי אתם מדברים</span> &mdash; מגנה עליכם מפני:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     קמעונאים מקוונים יודעים שאנשים עם הכנסה נמוכה יותר נוטים יותר לבצע רכישות דחופות, ולכן הם עשויים לגבות מחירים גבוהים יותר או להסיר הנחות.
 </p>
 <p>
-    חלק מחברות פיננסיות וביטוח משתמשות בגרפים חברתיים כדי לקבוע שיעורי ריבית ופרמיות. לעתים קרובות זה גורם לאנשים עם הכנסה נמוכה יותר לשלם יותר — זה ידוע בתור <a href="https://fairbydesign.com/povertypremium/" target="_blank">'פרמיית עוני'</a>.
+    חלק מחברות פיננסיות וביטוח משתמשות בגרפים חברתיים כדי לקבוע שיעורי ריבית ופרמיות. לעתים קרובות זה גורם לאנשים עם הכנסה נמוכה יותר לשלם יותר &mdash; זה ידוע בתור <a href='https://fairbydesign.com/povertypremium/' target='_blank'>'פרמיית עוני'</a>.
 </p>
 <p>
     רשת SimpleX מגנה על פרטיות החיבורים שלך טוב יותר מכל אלטרנטיבה, ומונעת לחלוטין את זמינות הגרף החברתי שלך לחברות או ארגונים. אפילו כאשר אנשים משתמשים בשרתים שתצורתם נקבעה מראש באפליקציות SimpleX Chat, מפעילי השרת אינם יודעים את מספר המשתמשים או את החיבורים שלהם.
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1001,7 +1006,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    לפני זמן לא רב ראינו את הבחירות הראשיות שעברו מניפולציות על ידי <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">חברת ייעוץ מכובדת</a> שהשתמשה בגרפים החברתיים שלנו כדי לעוות את השקפתנו על העולם האמיתי ולתמרן את ההצבעות שלנו.
+    לפני זמן לא רב ראינו את הבחירות הראשיות שעברו מניפולציות על ידי <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>חברת ייעוץ מכובדת</a> שהשתמשה בגרפים החברתיים שלנו כדי לעוות את השקפתנו על העולם האמיתי ולתמרן את ההצבעות שלנו.
 </p>
 <p>
     כדי להיות אובייקטיבי ולקבל החלטות עצמאיות, עליך לשלוט במרחב המידע שלך. זה אפשרי רק אם אתה משתמש ברשת תקשורת פרטית שאין לה גישה לגרף החברתי שלך.
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1045,16 +1050,16 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    לכולם צריך להיות אכפת מהפרטיות והאבטחה של התקשורת שלהם — שיחות לא מזיקות עלולות להעמיד אתכם בסכנה, גם אם אין לכם מה להסתיר.
+    לכולם צריך להיות אכפת מהפרטיות והאבטחה של התקשורת שלהם &mdash; שיחות לא מזיקות עלולות להעמיד אתכם בסכנה, גם אם אין לכם מה להסתיר.
 </p>
 <p>
-    אחד הסיפורים המזעזעים ביותר הוא החוויה של <a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">מוחמד אולד סלאחי</a> המתוארת בספר הזיכרונות שלו ומוצגת בסרט "המאוריטני". הוא הוכנס למתקן המעצר בגואנטנמו, ללא משפט, ועונה שם במשך 15 שנים לאחר שיחת טלפון לקרוב משפחתו באפגניסטן, בחשד שהיה מעורב בפיגועים ב-11 בספטמבר, למרות שחי בגרמניה בעשר השנים הקודמות.
+    אחד הסיפורים המזעזעים ביותר הוא החוויה של <a href='https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi' target='_blank'>מוחמד אולד סלאחי</a> המתוארת בספר הזיכרונות שלו ומוצגת בסרט "המאוריטני". הוא הוכנס למתקן המעצר בגואנטנמו, ללא משפט, ועונה שם במשך 15 שנים לאחר שיחת טלפון לקרוב משפחתו באפגניסטן, בחשד שהיה מעורב בפיגועים ב-11 בספטמבר, למרות שחי בגרמניה בעשר השנים הקודמות.
 </p>
 <p>
-    אנשים רגילים נעצרים על מה שהם משתפים באינטרנט, אפילו דרך החשבונות ה'אנונימיים' שלהם, <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout -catholic-mother-malicious-online-posts.html" target="_blank">אפילו במדינות דמוקרטיות</a>.
+    אנשים רגילים נעצרים על מה שהם משתפים באינטרנט, אפילו דרך החשבונות ה'אנונימיים' שלהם, <a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout -catholic-mother-malicious-online-posts.html' target='_blank'>אפילו במדינות דמוקרטיות</a>.
 </p>
 <p>
-    זה לא מספיק להשתמש במסנג'ר מוצפן מקצה לקצה, כולנו צריכים להשתמש במסנג'רים שמגנים על הפרטיות של הרשתות האישיות שלנו — שאליהן אנחנו מחוברים.
+    זה לא מספיק להשתמש במסנג'ר מוצפן מקצה לקצה, כולנו צריכים להשתמש במסנג'רים שמגנים על הפרטיות של הרשתות האישיות שלנו &mdash; שאליהן אנחנו מחוברים.
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1083,7 +1088,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">מדוע SimpleX הוא <span class="gradient-text">ייחודי</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">מדוע SimpleX הוא <span class='gradient-text'>ייחודי</span></h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">יש לך פרטיות מלאה</h3>
                             </div>
 
@@ -1109,7 +1114,7 @@ window.addEventListener('click',(e)=>{
     SimpleX מגן על פרטיות הפרופיל, אנשי הקשר והמטא נתונים שלכם, מסתיר אותם משרתי רשת SimpleX ומכל צופה.
 </p>
 <p>
-    בניגוד לכל רשת הודעות קיימת אחרת, ל-SimpleX אין מזהים המשויכים למשתמשים — <strong>אפילו לא מספרים אקראיים</strong>.
+    בניגוד לכל רשת הודעות קיימת אחרת, ל-SimpleX אין מזהים המשויכים למשתמשים &mdash; <strong>אפילו לא מספרים אקראיים</strong>.
 </p>
 
                                     </div>
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">עוד מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">הסתר מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">אתה מוגן<br>מפני ספאם וניצול לרעה</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">עוד מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">הסתר מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">אתה שולט בנתונים שלך</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleX מאחסן את כל נתוני המשתמש במכשירי הלקוח ב<strong>פורמט מסד נתונים מוצפן נייד</strong> — ניתן להעביר אותו למכשיר אחר.
+    SimpleX מאחסן את כל נתוני המשתמש במכשירי הלקוח ב<strong>פורמט מסד נתונים מוצפן נייד</strong> &mdash; ניתן להעביר אותו למכשיר אחר.
 </p>
 <p>
     ההודעות המוצפנות מקצה לקצה מוחזקות באופן זמני בשרתי ממסר של SimpleX עד שמתקבלות, ואז הן נמחקות לצמיתות.
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">עוד מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">הסתר מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">רשת SimpleX בבעלותך</h3>
                             </div>
 
@@ -1259,7 +1264,7 @@ window.addEventListener('click',(e)=>{
     רשת SimpleX מבוזרת לחלוטין ואינה תלויה בכל מטבע קריפטוגרפי או בכל רשת אחרת, מלבד האינטרנט.
 </p>
 <p>
-    אתם יכולים <strong>להשתמש ב-SimpleX עם השרתים שלכם</strong> או עם השרתים שסופקו על ידינו — ועדיין להתחבר לכל משתמש.
+    אתם יכולים <strong>להשתמש ב-SimpleX עם השרתים שלכם</strong> או עם השרתים שסופקו על ידינו &mdash; ועדיין להתחבר לכל משתמש.
 </p>
 
                                     </div>
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">עוד מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">הסתר מידע</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1320,10 +1325,10 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    בניגוד לרשתות הודעות אחרות, ב-SimpleX <strong>אין מזהים המשויכים למשתמשים</strong>. אנחנו לא מסתמכים על מספרי טלפון, כתובות מבוססות דומיין (כמו אימייל או XMPP), שמות משתמש, מפתחות ציבוריים או אפילו מספרים אקראיים כדי לזהות את המשתמשים שלנו — מפעילי שרתי SimpleX אינם יודעים כמה אנשים משתמשים בשרתים שלהם.
+    בניגוד לרשתות הודעות אחרות, ב-SimpleX <strong>אין מזהים המשויכים למשתמשים</strong>. אנחנו לא מסתמכים על מספרי טלפון, כתובות מבוססות דומיין (כמו אימייל או XMPP), שמות משתמש, מפתחות ציבוריים או אפילו מספרים אקראיים כדי לזהות את המשתמשים שלנו &mdash; מפעילי שרתי SimpleX אינם יודעים כמה אנשים משתמשים בשרתים שלהם.
 </p>
 <p>
-    כדי להעביר הודעות, SimpleX משתמשת ב-<a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">כתובות אנונימיות זוגיות</a> של תורי הודעות חד-כיווניים, נפרדים להודעות נכנסות ויוצאות, בדרך כלל דרך שרתים שונים.
+    כדי להעביר הודעות, SimpleX משתמשת ב-<a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>כתובות אנונימיות זוגיות</a> של תורי הודעות חד-כיווניים, נפרדים להודעות נכנסות ויוצאות, בדרך כלל דרך שרתים שונים.
 </p>
 <p>
     עיצוב זה מגן על הפרטיות של מי שאתה מתקשר איתו, מסתיר אותה משרתי רשת SimpleX ומכל צופה. כדי להסתיר את כתובת ה-IP שלך מהשרתים, אתה יכול<strong>להתחבר לשרתי SimpleX באמצעות Tor</strong>.
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     שלא כמו שרתי רשת מאוחדים (דוא"ל, XMPP או Matrix), שרתי SimpleX אינם מאחסנים חשבונות משתמשים, הם רק מעבירים הודעות, ומגנים על הפרטיות של שני הצדדים.
 </p>
 <p>
-    אין מזהים או טקסט מוצפן משותף בין תעבורת שרת שנשלחה ומתקבלת — אם מישהו צופה בזה, הם לא יכולים לקבוע בקלות מי מתקשר עם מי, גם אם ה-TLS נפרץ.
+    אין מזהים או טקסט מוצפן משותף בין תעבורת שרת שנשלחה ומתקבלת &mdash; אם מישהו צופה בזה, הם לא יכולים לקבוע בקלות מי מתקשר עם מי, גם אם ה-TLS נפרץ.
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">מבוזר לחלוטין — המשתמשים הם הבעלים של רשת SimpleX</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">מבוזר לחלוטין &mdash; המשתמשים הם הבעלים של רשת SimpleX</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     ניתן <strong>להשתמש ב-SimpleX עם השרתים שלכם</strong> ועדיין לתקשר עם אנשים המשתמשים בשרתים שתצורתם נקבעה מראש באפליקציות.
 </p>
 <p>
-    רשת SimpleX משתמשת ב<a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">פרוטוקול פתוח</a> ומספקת <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK ליצירת צ'אט בוטים</a>, המאפשר הטמעה של שירותים שמשתמשים יכולים לתקשר איתם באמצעות אפליקציות SimpleX Chat — אנחנו ממש מצפים לראות אילו שירותי SimpleX אתם יכולים לבנות.
+    רשת SimpleX משתמשת ב<a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>פרוטוקול פתוח</a> ומספקת <a href='https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript' target='_blank'>SDK ליצירת צ'אט בוטים</a>, המאפשר הטמעה של שירותים שמשתמשים יכולים לתקשר איתם באמצעות אפליקציות SimpleX Chat &mdash; אנחנו ממש מצפים לראות אילו שירותי SimpleX אתם יכולים לבנות.
 </p>
 <p>
-    אם אתם שוקלים לפתח עבור רשת SimpleX, למשל, את הצ'אט בוט עבור משתמשי אפליקציית SimpleX, או שילוב של ספריית SimpleX Chat באפליקציות לנייד שלכם, אנא <a href="https://simplex.chat/contact# /?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JB38MZG9NLUZ_8JB38t%2ADKeAyGeee 8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">צרו קשר</a> לכל עצה ותמיכה.
+    אם אתם שוקלים לפתח עבור רשת SimpleX, למשל, את הצ'אט בוט עבור משתמשי אפליקציית SimpleX, או שילוב של ספריית SimpleX Chat באפליקציות לנייד שלכם, אנא <a href='https://simplex.chat/contact# /?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JB38MZG9NLUZ_8JB38t%2ADKeAyGeee 8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>צרו קשר</a> לכל עצה ותמיכה.
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">הודעות מוצפנות מקצה לקצה עם סימונים ואפשרויות עריכה</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">תמונות, וידאו וקבצים<br>בהצפנת קצה-אל-קצה</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">קבוצות סודיות מבוזרות —<br>רק המשתמשים יודעים שהן קיימות</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">קבוצות סודיות מבוזרות &mdash;<br>רק המשתמשים יודעים שהן קיימות</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">הודעות קוליות מוצפנות מקצה לקצה</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">הודעות נעלמות</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">שיחות שמע ווידאו<br>מוצפנות מקצה לקצה</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">מסד נתונים מוצפן נייד — העבר פרופיל למכשיר אחר</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">מסד נתונים מוצפן נייד &mdash; העבר פרופיל למכשיר אחר</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">מצב זהות נסתרת —<br>ייחודי ל-SimpleX Chat</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">מצב זהות נסתרת &mdash;<br>ייחודי ל-SimpleX Chat</p>
             </div>
             
         </div>
@@ -1570,7 +1575,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">מה הופך את SimpleX ל<span class="gradient-text">פרטי</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">מה הופך את SimpleX ל<span class='gradient-text'>פרטי</span></h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">מזהים זמניים אנונימיים בזוגות</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">החלפת מפתחות<br>מחוץ לרשת</h3>
@@ -1614,14 +1619,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">2 שכבות של<br>הצפנה מקצה לקצה</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">פרוטוקול ראצ'ט כפול —<br>העברת הודעות OTR עם סודיות מושלמת קדימה ושחזור פריצה.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">פרוטוקול ראצ'ט כפול &mdash;<br>העברת הודעות OTR עם סודיות מושלמת קדימה ושחזור פריצה.</p>
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">תיבת הצפנה NaCL בכל תור כדי למנוע קורלציית תעבורה בין תורי הודעות במקרה שאבטחת TLS נפגעה.</p>
                             
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">בדיקת תקינות<br>ההודעה</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">שכבה נוספת של<br>הצפנת שרת</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">ערבוב הודעות<br>לשם הפחתת קורלציה</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">שרתי SimpleX פועלים כצמתי ערבוב עם זמן השהיה נמוך — להודעות הנכנסות והיוצאות יש סדר שונה.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">שרתי SimpleX פועלים כצמתי ערבוב עם זמן השהיה נמוך &mdash; להודעות הנכנסות והיוצאות יש סדר שונה.</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">הקישו כדי לסגור</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">תעבורת TLS<br>מאובטחת ומאומתת</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">אופציונלי<br>גישה דרך Tor</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">תורי הודעות<br>חד-כיווניים</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">שכבות מרובות של<br>ריפוד תוכן</h3>
@@ -1774,14 +1779,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5"><span class="gradient-text">רשת</span> SimpleX</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5"><span class='gradient-text'>רשת</span> SimpleX</h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">SimpleX Chat מספק את הפרטיות הטובה ביותר על ידי שילוב היתרונות של P2P ורשתות מאוחדות.</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">בניגוד לרשתות P2P</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         כל ההודעות נשלחות דרך השרתים, שמספקים פרטיות טובה יותר של מטא נתונים וגם מסירת הודעות אסינכרונית אמינה, תוך הימנעות מהרבה <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">בעיות של רשתות P2P</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">השוואה לפרוטוקולי העברת הודעות P2P</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1797,26 +1802,26 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    לפרוטוקולי הודעות ואפליקציות <a href="https://en.wikipedia.org/wiki/Peer-to-peer">P2P</a> יש בעיות שונות שהופכות אותן לפחות אמינות מ-SimpleX, מורכבות יותר לניתוח, ופגיעות למספר סוגי התקפות.
+    לפרוטוקולי הודעות ואפליקציות <a href='https://en.wikipedia.org/wiki/Peer-to-peer'>P2P</a> יש בעיות שונות שהופכות אותן לפחות אמינות מ-SimpleX, מורכבות יותר לניתוח, ופגיעות למספר סוגי התקפות.
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
-        רשתות P2P מסתמכות על גרסה כלשהי של <a href="https://en.wikipedia.org/wiki/Distributed_hash_table">DHT</a> כדי לנתב הודעות. עיצובי DHT צריכים לאזן בין אחריות מסירה לבין זמן השהיה. ל- SimpleX יש גם אחריות מסירה טובה יותר וגם השהיה נמוכה יותר מאשר P2P, מכיוון שניתן להעביר את ההודעה כיתירות דרך מספר שרתים במקביל, באמצעות השרתים שנבחרו על ידי הנמען. ברשתות P2P ההודעה מועברת דרך <em>O(log N)</em> צמתים ברצף, תוך שימוש בצמתים שנבחרו על ידי האלגוריתם.
+        רשתות P2P מסתמכות על גרסה כלשהי של <a href='https://en.wikipedia.org/wiki/Distributed_hash_table'>DHT</a> כדי לנתב הודעות. עיצובי DHT צריכים לאזן בין אחריות מסירה לבין זמן השהיה. ל- SimpleX יש גם אחריות מסירה טובה יותר וגם השהיה נמוכה יותר מאשר P2P, מכיוון שניתן להעביר את ההודעה כיתירות דרך מספר שרתים במקביל, באמצעות השרתים שנבחרו על ידי הנמען. ברשתות P2P ההודעה מועברת דרך <em>O(log N)</em> צמתים ברצף, תוך שימוש בצמתים שנבחרו על ידי האלגוריתם.
     </li>
     <li>
         לעיצוב של SimpleX, בניגוד לרוב רשתות ה-P2P, אין מזהי משתמש גלובלי מכל סוג שהוא, אפילו זמני, והוא משתמש רק במזהים זמניים זוגיים, המספקים אנונימיות טובה יותר והגנה על מטא נתונים.
     </li>
     <li>
-        P2P אינו פותר את בעיית <a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">התקפת MITM</a>, ורוב ההטמעות הקיימות אינן משתמשות בהודעות out-of-band עבור החלפת המפתחות הראשונית. SimpleX משתמש בהודעות out-of-band או, במקרים מסוימים, בחיבורים מאובטחים ומהימנים קיימים מראש לצורך החלפת המפתחות הראשונית.
+        P2P אינו פותר את בעיית <a href='https://en.wikipedia.org/wiki/Man-in-the-middle_attack'>התקפת MITM</a>, ורוב ההטמעות הקיימות אינן משתמשות בהודעות out-of-band עבור החלפת המפתחות הראשונית. SimpleX משתמש בהודעות out-of-band או, במקרים מסוימים, בחיבורים מאובטחים ומהימנים קיימים מראש לצורך החלפת המפתחות הראשונית.
     </li>
     <li>
-        יישומי P2P עלולים להיחסם על ידי ספקי אינטרנט מסוימים (כמו <a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a>). SimpleX אינו תלוי בתעבורה - הוא יכול לעבוד על פרוטוקולי אינטרנט סטנדרטיים, למשל WebSockets.
+        יישומי P2P עלולים להיחסם על ידי ספקי אינטרנט מסוימים (כמו <a href='https://en.wikipedia.org/wiki/BitTorrent'>BitTorrent</a>). SimpleX אינו תלוי בתעבורה - הוא יכול לעבוד על פרוטוקולי אינטרנט סטנדרטיים, למשל WebSockets.
     </li>
     <li>
-        כל רשתות ה-P2P המוכרות עשויות להיות פגיעות ל<a href="https://en.wikipedia.org/wiki/Sybil_attack">התקפת Sybil</a>, מכיוון שכל צומת ניתן לגילוי, והרשת פועלת כמכלול. אמצעים ידועים כדי למתן את זה דורשים רכיב ריכוזי או <a href="https://en.wikipedia.org/wiki/Proof_of_work">מערכת הוכחת עבודה</a> יקרה. לרשת SimpleX אין יכולת גילוי של שרת, היא מפוצלת ופועלת כמספר תת-רשתות מבודדות, מה שהופך התקפות ברחבי הרשת לבלתי אפשריות.
+        כל רשתות ה-P2P המוכרות עשויות להיות פגיעות ל<a href='https://en.wikipedia.org/wiki/Sybil_attack'>התקפת Sybil</a>, מכיוון שכל צומת ניתן לגילוי, והרשת פועלת כמכלול. אמצעים ידועים כדי למתן את זה דורשים רכיב ריכוזי או <a href='https://en.wikipedia.org/wiki/Proof_of_work'>מערכת הוכחת עבודה</a> יקרה. לרשת SimpleX אין יכולת גילוי של שרת, היא מפוצלת ופועלת כמספר תת-רשתות מבודדות, מה שהופך התקפות ברחבי הרשת לבלתי אפשריות.
     </li>
     <li>
-        רשתות P2P עשויות להיות פגיעות ל<a href="https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent">התקפת DRDoS</a> , כאשר הלקוחות יכולים לשדר מחדש ולהגביר את התעבורה, וכתוצאה מכך מניעת שירות בכל הרשת. לקוחות SimpleX מעבירים רק תעבורה מחיבור ידוע ואינם יכולים להיות בשימוש על ידי תוקף כדי להגביר את התעבורה בכל הרשת.
+        רשתות P2P עשויות להיות פגיעות ל<a href='https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent'>התקפת DRDoS</a> , כאשר הלקוחות יכולים לשדר מחדש ולהגביר את התעבורה, וכתוצאה מכך מניעת שירות בכל הרשת. לקוחות SimpleX מעבירים רק תעבורה מחיבור ידוע ואינם יכולים להיות בשימוש על ידי תוקף כדי להגביר את התעבורה בכל הרשת.
     </li>
 </ol>
                         </div>
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">בניגוד לרשתות מאוחדות</h3>
@@ -1862,13 +1867,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">רשת SimpleX</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        השרתים מספקים <span class="text-active-blue">תורים חד-כיווניים</span> לחיבור המשתמשים, אך הם לא יכול לראות את גרף חיבור הרשת — רק המשתמשים יכולים לראות זאת.
+                        השרתים מספקים <span class='text-active-blue'>תורים חד-כיווניים</span> לחיבור המשתמשים, אך הם לא יכול לראות את גרף חיבור הרשת &mdash; רק המשתמשים יכולים לראות זאת.
                     </p>
                 </div>
             </div>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. חוויית משתמש</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             אתם יכולים ליצור אנשי קשר וקבוצות, ולנהל שיחות דו-כיווניות, כמו בכל תוכנה אחרת לשליחת הודעות.
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. איך זה עובד</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             עבור כל חיבור, שני תורי העברת הודעות נפרדים משמשים לשליחה וקבלה של הודעות דרך שרתים שונים.
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. מה השרתים רואים</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             לשרתים יש אישורים אנונימיים נפרדים לכל תור, ואינם יודעים לאילו משתמשים הם שייכים.
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal, פלטפורמות גדולות</th>
                         <th class="pb-4">XMPP, Matrix</th>
@@ -2111,7 +2116,7 @@ window.addEventListener("load", function () {
                     <li> ממסרי SimpleX אינם יכולים לסכן הצפנה מקצה לקצה. ודא קוד אבטחה כדי לצמצם התקפות על ערוץ "מחוץ לרשת"</li>
                     <li> אם השרתי המפעיל נפגעים. אמת את קוד האבטחה ב-Signal ובכמה אפליקציות אחרות כדי למתן את זה</li>
                     <li> אינו מגן על פרטיות המטא נתונים של המשתמשים</li>
-                    <li> בעוד שרשתות עמית לעמית (P2P) מבוזרות, הן אינן מאוחדות (פדרטיביות) — הן פועלות כרשת יחידה</li>
+                    <li> בעוד שרשתות עמית לעמית (P2P) מבוזרות, הן אינן מאוחדות (פדרטיביות) &mdash; הן פועלות כרשת יחידה</li>
                     <li> לרשתות P2P יש רשות מרכזית או שכל הרשת יכולה להיפגע - <a class="underline text-primary-light dark:text-primary-dark underline-offset-2" href="https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols">ראו כאן</a></li>
                 </ol>
             </div>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">הירשמו כדי לקבל את העדכונים שלנו</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
-            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא" ל="" שלכם"="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
+            <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="הזינו את כתובת הדוא"ל שלכם">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">הורידו את <a href="/downloads">אפליקציית שולחן העבודה</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/he/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/he/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/he/why.md b/he/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/he/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/he/why/index.html b/he/why/index.html
index 979603d3b6..3b374851e8 100644
--- a/he/why/index.html
+++ b/he/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/he/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/hu/contact.md b/hu/contact.md
new file mode 100644
index 0000000000..443b6b0a2e
--- /dev/null
+++ b/hu/contact.md
@@ -0,0 +1,66 @@
+# Ez egy meghívó a SimpleX Chaten való beszélgetéshez
+
+## Olvassa be a QR-kódot a SimpleX Chat alkalmazással az eszköze segítségével.
+
+A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt — azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+
+Még nem töltötte le a SimpleX Chatet?
+
+Az alkalmazás letöltéséhez használja az alábbi hivatkozások egyikét.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+QR-kód beolvasása mobilalkalmazásból
+
+# Ez egy meghívó a SimpleX Chaten való beszélgetéshez
+
+A kapcsolat létrehozásához:
+
+Telepítse a SimpleX alkalmazást
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid)
+
+1
+
+Kapcsolódás az alkalmazásban
+
+SimpleX alkalmazás megnyitása
+
+2
+
+Koppintson a „kapcsolódás” gombra az alkalmazásban
+
+3
+
+## Olvassa be a QR-kódot a SimpleX Chat alkalmazással
+
+A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt —
+azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+
+## A SimpleX chat telepítése a terminálhoz
+
+Használja ezt a parancsot:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Az utasításokat megtekintheti a SimpleX Chat GitHub-tárolójában és választ kaphat arra, hogy hogyan töltse le vagy fordítsa le a forráskódból.
+
+---
+
+## Ha már telepítette a SimpleX Chatet a terminálhoz
+
+Ha már telepítette a SimpleX Chat a terminálhoz v1.0.0+, másolja be az alábbi parancsot, és használja a csevegésben:
+
+## Csatlakozzon a közösségeinkhez SimpleX
+
+Csatlakozzon a beszélgetéseinkhez
+
+[Csatlakozzon a REDDIT közösséghez](https://www.reddit.com/r/SimpleXChat/) [Csatlakozzon hozzánk a GitHubon](https://github.com/simplex-chat) [Adományozzon és segítsen nekünk](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Regisztráljon a hírleveleinkre, hogy ne maradjon le semmiről
+
+---
+
+A SimpleX számítógépes alkalmazásának [letöltése](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid)
diff --git a/hu/contact/index.html b/hu/contact/index.html
index fd4d26acf1..6dc9cf4f29 100644
--- a/hu/contact/index.html
+++ b/hu/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Ez egy meghívó a SimpleX Chaten való beszélgetéshez</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Olvassa be a QR-kódot a SimpleX Chat alkalmazással az eszköze segítségével.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt — azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+                A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt &mdash; azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
             </p>
             <p class="text-grey-black dark:text-white text-base">Még nem töltötte le a SimpleX Chatet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Az alkalmazás letöltéséhez használja az alábbi hivatkozások egyikét.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Telepítse a SimpleX alkalmazást</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Olvassa be a QR-kódot a SimpleX Chat alkalmazással</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt —<br> azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+                            A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt &mdash;<br> azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">A SimpleX chat telepítése a terminálhoz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-tárolójában</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Ha már telepítette a SimpleX Chatet a terminálhoz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Regisztráljon a hírleveleinkre, hogy ne maradjon le semmiről</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Adjon meg egy e-mail-címet">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">A SimpleX számítógépes alkalmazásának <a href="/downloads">letöltése</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/fdroid.md b/hu/fdroid.md
new file mode 100644
index 0000000000..bef79923ec
--- /dev/null
+++ b/hu/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat az F-Droidon keresztül
+
+### A SimpleX Chat tárolója
+
+A fejlesztők által készített stabil és béta verziók
+
+Ha hozzá szeretné adni az F-Droid klienséhez, olvassa be a QR-kódot, vagy használja ezt a webcímet:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Az aláírókulcs ujjlenyomata (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid-tároló
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+F-Droid.org által készített stabil verziók
+
+A kiadások ebben a tárolóban néhány napot késnek.
+
+A SimpleX Chat és az F-Droid-tároló különböző kulcsokkal írják alá az összeállításokat. A váltáshoz [exportálja](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) a csevegési adatbázist és telepítse újra az alkalmazást.
diff --git a/hu/fdroid/index.html b/hu/fdroid/index.html
index 2b2d1ea3f2..ac35d0e09b 100644
--- a/hu/fdroid/index.html
+++ b/hu/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat az F-Droidon keresztül</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">A fejlesztők által készített stabil és béta verziók</p>
                         <p>Ha hozzá szeretné adni az F-Droid klienséhez, <span class="hide-on-mobile">olvassa be a QR-kódot, vagy</span> használja ezt a webcímet:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Az aláírókulcs ujjlenyomata (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid-tároló</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">F-Droid.org által készített stabil verziók</p>
                 <p class="mb-2">A kiadások ebben a tárolóban néhány napot késnek.</p>
                 <p class="mb-2">A SimpleX Chat és az F-Droid-tároló különböző kulcsokkal írják alá az összeállításokat. A váltáshoz <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exportálja</a> a csevegési adatbázist és telepítse újra az alkalmazást.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/file.md b/hu/file.md
new file mode 100644
index 0000000000..1d142f3786
--- /dev/null
+++ b/hu/file.md
@@ -0,0 +1,31 @@
+# SimpleX fájlátvitel
+
+Húzzon ide
+
+vagy
+
+Válasszon ki egy fájlt
+
+Legfeljebb 100 MB – a [SimpleX Chat alkalmazás](https://simplex.chat/downloads) viszont 1 GB méretű fájlokat is támogat
+
+Fájlok biztonságos küldése végpontok közötti titkosítással – felhasználói fiókok és nyomon követés nélkül.
+
+## Szerezze be a SimpleX Chat alkalmazást – a legbiztonságosabb és legbizalmasabb üzenetváltó programot
+
+Az imént használt fájlátvitel ugyanazt az útválasztó protokollt használja, mint a SimpleX Chat alkalmazás. Az alkalmazás végpontok közötti titkosított üzenetküldést, hang- és videohívásokat, csoportos csevegéseket és fájlok küldését teszi lehetővé. Nem szükséges hozzá felhasználói fiók, telefonszám, e-mail-cím és nem használ felhasználói profilazonosítókat sem.
+
+# XFTP-protokoll: a legbiztonságosabb fájlátvitel
+
+### Nincs szükség felhasználói fiókra
+
+Minden fájldarab új, véletlenszerű kulcsot használ. Az útválasztóknak nincsenek „felhasználóik” vagy „fájljaik” – rögzített méretű titkosított fájldarabokat továbbítanak.
+
+### Háromrétegű titkosítás a böngészőben
+
+A fájl titkosítási kulcsa csak a webcím kivonattöredékében található – a böngésző soha nem küldi el azt a kiszolgálónak. A fájlok háromrétegű titkosítással rendelkeznek: TLS-átviteli, címzettenkénti (egyedi, ideiglenes kulcs átvitelenként) és végpontok közötti titkosítással.
+
+### Független útválasztók
+
+Amikor a fájl töredékekre oszlik, akkor a független felek által üzemeltetett hálózati útválasztókon keresztül kerül továbbításra. Egyetlen üzemeltető sem láthatja a fájl tényleges méretét és nevét. Még ha egy útválasztó biztonsága meg is sérül, csak a rögzített méretű titkosított töredékeket „láthatja”. A fájltöredékeket a hálózati útválasztók körülbelül 48 órán át tárolják a gyorsítótárban.
+
+[Olvassa el az XFTP-protokoll leírását →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/hu/file/index.html b/hu/file/index.html
index da744760a1..33fd139d3b 100644
--- a/hu/file/index.html
+++ b/hu/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">SimpleX fájlátvitel</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Húzzon ide</p>
@@ -699,11 +706,11 @@ window.addEventListener('click',(e)=>{
       Az imént használt fájlátvitel ugyanazt az útválasztó protokollt használja, mint a SimpleX Chat alkalmazás. Az alkalmazás végpontok közötti titkosított üzenetküldést, hang- és videohívásokat, csoportos csevegéseket és fájlok küldését teszi lehetővé. Nem szükséges hozzá felhasználói fiók, telefonszám, e-mail-cím és nem használ felhasználói profilazonosítókat sem.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/hu/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/hu/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/index.html b/hu/index.html
index 51d3351077..138839a9cd 100644
--- a/hu/index.html
+++ b/hu/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/hu/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/hu/fdroid" title="SimpleX alkalmazás az F-Droidon keresztül"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Nyilvános betekintés az iOS alkalmazás fejlesztésébe a TestFlighton"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Nyilvános betekintés az iOS alkalmazás fejlesztésébe a TestFlighton" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Biztonsági auditok" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Most</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">2027. jún.</span>
diff --git a/hu/index.md b/hu/index.md
new file mode 100644
index 0000000000..02491c5ca2
--- /dev/null
+++ b/hu/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Legyen szabad
+
+## A saját hálózatában
+
+Az első hálózat felhasználói azonosítók nélkül.
+A saját partnerei, csoportjai és csatornái felett Ön rendelkezik.
+
+Fektessen be a SimpleX Chatbe. [Tudjon meg többet.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX alkalmazás az F-Droidon keresztül](https://simplex.chat/hu/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Biztonsági auditok](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Biztonsági
+auditok
+
+[A Privacy Guides üzenetváltó ajánlásai](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix ajánlás](https://www.whonix.org/wiki/Chat#Recommendation) [A Heise Online kiadványai](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Áttekintette: Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interjú](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Senki sem láthatja, kivel beszélget
+
+Még a kiszolgálók sem – az összes üzenet véletlenszerű zajnak tűnik.
+
+Naponta több tízmillió üzenet kerül kézbesítésre privát módon.
+
+[Tudjon meg többet a SimpleX üzenetváltó alkalmazásról](https://simplex.chat/hu/messaging)
+
+## A hálózat az Öné
+
+Minden partnere és csoportja az Ön eszközén van tárolva, nem pedig egy ismeretlen kiszolgáló adatbázisában.
+
+Egyetlen szervezet sem irányítja a hálózatot – bárki üzemeltethet kiszolgálókat.
+
+[Miért készítjük](https://simplex.chat/hu/why)
+
+## A felhasználók finanszírozzák
+
+A függetlenség megőrzéséhez a nagy csatornák és közösségek fizetni fognak a kiszolgálóikért.
+
+És a felhasználók mostantól befektethetnek a SimpleX Chatbe — a közösségi finanszírozás elindult!
+
+[Befektetés a SimpleX Chatbe](https://simplex.chat/crowdfunding/)
+
+## A SimpleX ütemterve a szabad internethez
+
+2026
+
+: Skálázódás nagy közösségekre
+
+Központosított platformok elhagyása
+
+2027. jún.
+
+: Fenntartható közösségek és kiszolgálók
+
+Közösségi kreditek elindítása
+
+2027. dec.
+
+: Közösségek növelése
+
+Eszközök biztosítása a közösségek népszerűsítéséhez
+
+[SimpleX felhasználók csoportja](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Csatlakozzon a SimpleX közösségekhez
+
+Több mint 2 millió ember töltötte le a SimpleX alkalmazások egyikét.
+
+Találja meg a kedvenc csatornáit és közösségeit a csoportjegyzékben, vagy hozza létre a sajátját!
+
+[SimpleX-csoportjegyzék megtekintése](https://simplex.chat/directory)
diff --git a/hu/invitation.md b/hu/invitation.md
new file mode 100644
index 0000000000..aa891093fc
--- /dev/null
+++ b/hu/invitation.md
@@ -0,0 +1,66 @@
+# Kapott egy egyszer használható meghívót a SimpleX Chaten való beszélgetéshez
+
+## Olvassa be a QR-kódot a SimpleX Chat alkalmazással az eszköze segítségével.
+
+A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt — azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+
+Még nem töltötte le a SimpleX Chatet?
+
+Az alkalmazás letöltéséhez használja az alábbi hivatkozások egyikét.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+QR-kód beolvasása mobilalkalmazásból
+
+# Kapott egy egyszer használható meghívót a SimpleX Chaten való beszélgetéshez
+
+A kapcsolat létrehozásához:
+
+Telepítse a SimpleX alkalmazást
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid)
+
+1
+
+Kapcsolódás az alkalmazásban
+
+SimpleX alkalmazás megnyitása
+
+2
+
+Koppintson a „kapcsolódás” gombra az alkalmazásban
+
+3
+
+## Olvassa be a QR-kódot a SimpleX Chat alkalmazással
+
+A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt —
+azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+
+## A SimpleX chat telepítése a terminálhoz
+
+Használja ezt a parancsot:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Az utasításokat megtekintheti a SimpleX Chat GitHub-tárolójában és választ kaphat arra, hogy hogyan töltse le vagy fordítsa le a forráskódból.
+
+---
+
+## Ha már telepítette a SimpleX Chatet a terminálhoz
+
+Ha már telepítette a SimpleX Chat a terminálhoz v1.0.0+, másolja be az alábbi parancsot, és használja a csevegésben:
+
+## Csatlakozzon a közösségeinkhez SimpleX
+
+Csatlakozzon a beszélgetéseinkhez
+
+[Csatlakozzon a REDDIT közösséghez](https://www.reddit.com/r/SimpleXChat/) [Csatlakozzon hozzánk a GitHubon](https://github.com/simplex-chat) [Adományozzon és segítsen nekünk](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Regisztráljon a hírleveleinkre, hogy ne maradjon le semmiről
+
+---
+
+A SimpleX számítógépes alkalmazásának [letöltése](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/hu/fdroid)
diff --git a/hu/invitation/index.html b/hu/invitation/index.html
index 74769c1992..302f8b25f0 100644
--- a/hu/invitation/index.html
+++ b/hu/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Kapott egy egyszer használható meghívót a SimpleX Chaten való beszélgetéshez</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Olvassa be a QR-kódot a SimpleX Chat alkalmazással az eszköze segítségével.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt — azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+                A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt &mdash; azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
             </p>
             <p class="text-grey-black dark:text-white text-base">Még nem töltötte le a SimpleX Chatet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Az alkalmazás letöltéséhez használja az alábbi hivatkozások egyikét.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Telepítse a SimpleX alkalmazást</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Olvassa be a QR-kódot a SimpleX Chat alkalmazással</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt —<br> azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
+                            A hivatkozásban szereplő nyilvános kulcsok és az üzenetek várólistájának címe NEM lesz elküldve a hálózaton keresztül, amikor megtekinti ezt az oldalt &mdash;<br> azokat, a hivatkozás webcímének kivonattöredéke tartalmazza.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">A SimpleX chat telepítése a terminálhoz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub-tárolójában</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Ha már telepítette a SimpleX Chatet a terminálhoz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Regisztráljon a hírleveleinkre, hogy ne maradjon le semmiről</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Adjon meg egy e-mail-címet">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">A SimpleX számítógépes alkalmazásának <a href="/downloads">letöltése</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/messaging.md b/hu/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Miért egyedülálló a SimpleX
+
+### Teljes magánéletet élvezhet
+
+A SimpleX megvédi a profilhoz tartozó partnereket és azok metaadatait is, elrejtve azokat a SimpleX hálózat kiszolgálói és a megfigyelők elől.
+
+Minden más létező üzenetküldő hálózattól eltérően a SimpleX nem rendelkezik a felhasználókhoz rendelt azonosítókkal — **még véletlenszerű számokkal sem**.
+
+### Véd a kéretlen tartalmaktól és a visszaélésektől
+
+Mivel a SimpleX hálózaton senkinek sincs azonosítója vagy állandó címe, ezért senki sem tud kapcsolatba lépni a felhasználókkal, hacsak nem osztanak meg egy egyszeri vagy ideiglenes felhasználói címet, például QR-kódot vagy hivatkozást.
+
+### A saját adatai felett rendelkezhet
+
+A SimpleX Chat az összes felhasználói adatot kizárólag a klienseken tárolja egy **hordozható titkosított adatbázis-formátumban** —, amely exportálható és átvihető bármely más támogatott eszközre.
+
+A végpontok között titkosított üzenetek átmenetileg a SimpleX átjátszóin tartózkodnak, amíg be nem érkeznek a címzetthez, majd automatikusan véglegesen törlődnek onnan.
+
+### A felhasználóké a SimpleX hálózat
+
+A SimpleX hálózat teljesen decentralizált és független bármely kriptopénztől vagy bármely más hálózattól, kivéve az internetet.
+
+Használhatja **a SimpleXet a saját kiszolgálóival** vagy az általunk biztosított kiszolgálókkal, és továbbra is kapcsolódhat bármely felhasználóhoz.
+
+# Személyazonosságának, profiljának, partnereinek és a metaadatok teljes körű védelme
+
+Más üzenetküldő hálózatoktól eltérően a SimpleX **nem rendel azonosítókat a felhasználókhoz**. Nem támaszkodik telefonszámokra, tartomány-alapú címekre (mint az e-mail, XMPP vagy a Matrix), felhasználónevekre, nyilvános kulcsokra vagy akár véletlenszerű számokra a felhasználók azonosításához — a SimpleX kiszolgálók üzemeltetői nem tudják, hogy hányan használják a kiszolgálóikat.
+
+Az üzenetek kézbesítéséhez a SimpleX egyirányú várólistákat használ az üzenetekhez, [páronkénti, névtelen címekkel](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier), külön a fogadott és külön az elküldött üzenetekhez, általában különböző kiszolgálókon keresztül.
+
+Ez a kialakítás védi partnerei adatait, elrejtve azt a SimpleX hálózat kiszolgálói és a külső megfigyelők elől. Az IP-címe elrejtésének érdekében a **Tor hálózaton keresztül is kapcsolódhat a SimpleX kiszolgálókhoz**.
+
+# A legjobb védelem a kéretlen tartalmak és a visszaélések ellen
+
+Mivel senki sem rendelkezik azonosítóval a SimpleX hálózaton, ezért senki sem tud kapcsolatba lépni Önnel, hacsak nem oszt meg egy egyszeri vagy ideiglenes felhasználói címet, például QR-kódot vagy hivatkozást.
+
+Még a felhasználói cím használata esetén is, aminek használata nem kötelező – ugyanakkor ez a kéretlen kapcsolatkérelmek küldésére is használható – módosíthatja vagy teljesen törölheti a címet anélkül, hogy elveszítené a meglévő kapcsolatait.
+
+# Az adatok biztonságát és kezelését teljes egészében kézben tarthatja
+
+A SimpleX Chat az összes felhasználói adatot kizárólag a klienseken tárolja egy **hordozható titkosított adatbázis-formátumban**, amely exportálható és átvihető bármely más támogatott eszközre.
+
+A végpontok között titkosított üzenetek átmenetileg a SimpleX átjátszóin tárolódnak, amíg meg nem érkeznek a címzetthez, majd automatikusan véglegesen törlődnek onnan.
+
+A föderált hálózatok kiszolgálóitól (e-mail, XMPP vagy Matrix) eltérően a SimpleX kiszolgálók nem tárolják a felhasználói fiókokat, csak továbbítják az üzeneteket, így védve mindkét fél magánéletét.
+
+A küldött és a fogadott kiszolgálóforgalom között nincsenek közös azonosítók vagy titkosított szövegek — ha bárki megfigyeli, nem tudja könnyen megállapítani, hogy ki kivel kommunikál, még akkor sem, ha a TLS-t kompromittálják.
+
+# Teljesen decentralizált — a SimpleX hálózat a felhasználóké
+
+Használhatja **a SimpleXet a saját kiszolgálóival**, és továbbra is kommunikálhat azokkal, akik az előre beállított kiszolgálókat használják az alkalmazásban.
+
+A SimpleX hálózat [nyitott protokollt](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) használ és [SDK-t biztosít a csevegési botok létrehozásához](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), lehetővé téve olyan szolgáltatások megvalósítását, amelyekkel a felhasználók a SimpleX Chat alkalmazásokon keresztül léphetnek kapcsolatba — mi már nagyon várjuk, hogy milyen SimpleX szolgáltatásokat készítenek a lelkes közreműködők.
+
+Ha a SimpleX hálózatra való fejlesztést fontolgatja, például a SimpleX alkalmazások felhasználóinak szánt csevegési botot, vagy a SimpleX Chat könyvtárbotjának integrálását más mobilalkalmazásba, [lépjen velünk kapcsolatba](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D), ha bármilyen tanácsot vagy támogatást szeretne kapni.
+
+## Funkciók
+
+Végpontok között titkosított üzenetek markdown formázással és szerkesztéssel
+
+Végpontok között titkosított
+képek, videók és fájlok
+
+Végpontok között titkosított, decentralizált csoportok — csak a felhasználók tudják, hogy ezek léteznek
+
+Végpontok között titkosított hangüzenetek
+
+Eltűnő üzenetek
+
+Végpontok között titkosított
+hang- és videóhívások
+
+Hordozható, titkosított alkalmazás-adattárolás — profil átköltöztetése egy másik eszközre
+
+Az inkognitómód —
+egyedülálló a SimpleX Chatben
+
+## Mitől lesz a SimpleX privát
+
+### Ideiglenes, névtelen, páronkénti azonosítók
+
+A SimpleX ideiglenes, névtelen, páros címeket és hitelesítő adatokat használ minden egyes felhasználói kapcsolathoz vagy csoporttaghoz.
+
+Lehetővé teszi az üzenetek felhasználói profilazonosítók nélküli kézbesítését, ami az alternatíváknál jobb metaadat-védelmet biztosít.
+
+### Sávon kívüli kulcscsere
+
+Számos kommunikációs hálózat sebezhető a kiszolgálók vagy a hálózat-szolgáltatók MITM-támadásaival szemben.
+
+Ennek megakadályozása érdekében a SimpleX alkalmazások egyszeri kulcsokat adnak át sávon kívül, amikor egy címet hivatkozásként vagy QR-kódként oszt meg.
+
+### Kétrétegű végpontok közötti titkosítás
+
+Dupla racsnis protokoll —
+OTR-üzenetküldés, kompromittálás előtti és utáni titkosság-védelemmel.
+
+NaCL cryptobox minden egyes várólistához, hogy megakadályozza a forgalom korrelációját az üzenetek várólistái között, ha a TLS veszélybe kerül.
+
+### Üzenetintegritás ellenőrzés
+
+Az integritás garantálása érdekében az üzenetek sorszámozással vannak ellátva, és tartalmazzák az előző üzenet kivonatát.
+
+Ha bármilyen üzenetet hozzáadnak, eltávolítanak vagy módosítanak, a címzett értesítést kap róla.
+
+### További rétege a kiszolgáló-titkosítás
+
+Kiegészítő kiszolgálótitkosítási réteg a címzettnek történő kézbesítéshez, hogy megakadályozza a fogadott és az elküldött kiszolgálóforgalom közötti korrelációt, ha a TLS veszélybe kerül.
+
+### Üzenetek keverése a korreláció csökkentése érdekében
+
+A SimpleX kiszolgálók alacsony késleltetésű keverési csomópontokként működnek — a bejövő és kimenő üzenetek sorrendje eltérő.
+
+### Biztonságos, hitelesített TLS-adatátvitel
+
+A kliens és a kiszolgálók közötti kapcsolatokhoz csak az erős algoritmusokkal rendelkező TLS 1.2/1.3 protokollt használja.
+
+A kiszolgáló ujjlenyomata és a csatornakötés megakadályozza a MITM- és a visszajátszási támadásokat.
+
+Az újrakapcsolódás le van tiltva a munkamenet elleni támadások megelőzése érdekében.
+
+### Hozzáférés a Tor hálózaton keresztül (nem kötelező)
+
+Az IP-cím védelme érdekében a kiszolgálókat a Tor hálózaton vagy más átvitelátfedő hálózaton keresztül is elérheti.
+
+A SimpleX, Tor hálózaton keresztüli használatához telepítse az [Orbot alkalmazást](https://guardianproject.info/apps/org.torproject.android/) és engedélyezze a SOCKS5 proxyt (vagy a VPN-t [az iOS-ban](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Egyirányú várólista az üzenetekhez
+
+Minden várólista az üzenetekhez egy irányba továbbítja az üzeneteket, a különböző küldési és fogadási címeken.
+
+Kevesebb támadási felülettel rendelkezik, mint a hagyományos üzenetváltó alkalmazások, és kevesebb metaadatot tesz elérhetővé.
+
+### Többrétegű tartalomkitöltés
+
+A SimpleX minden titkosítási réteghez tartalomkitöltést használ az üzenetméretre irányuló támadások meghiúsítása érdekében.
+
+A kiszolgálók és a hálózatot megfigyelők számára a különböző méretű üzenetek egyformának tűnnek.
+
+## SimpleX hálózat
+
+A SimpleX Chat a P2P- és a föderált hálózatok előnyeinek kombinálásával biztosítja a legjobb adatvédelmet.
+
+### A P2P-hálózatokkal ellentétben
+
+Minden üzenet a kiszolgálókon keresztül kerül elküldésre, ami jobb metaadat-védelmet és megbízható aszinkron üzenetkézbesítést biztosít, miközben elkerülhető a sok .
+
+# Összehasonlítás más P2P-üzenetküldő protokollokkal
+
+A [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) üzenetküldő protokollok és alkalmazások számos problémával küzdenek, amelyek miatt kevésbé megbízhatóak, mint a SimpleX, bonyolultabb az elemzésük és többféle támadással szemben sebezhetőek.
+
+1. A P2P-hálózatok az üzenetek továbbítására a [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) valamelyik változatát használják. A DHT kialakításakor egyensúlyt kell teremteni a kézbesítési garancia és a késleltetés között. A SimpleX jobb kézbesítési garanciával és alacsonyabb késleltetéssel rendelkezik, mint a P2P, mivel az üzenet redundánsan, a címzett által kiválasztott kiszolgálók segítségével több kiszolgálón keresztül párhuzamosan továbbítható. A P2P-hálózatokban az üzenet *O(log N)* csomóponton halad át szekvenciálisan, az algoritmus által kiválasztott csomópontok segítségével.
+2. A SimpleX kialakítása a legtöbb P2P-hálózattól eltérően nem rendelkezik semmiféle globális felhasználói azonosítóval, még ideiglenessel sem, és csak az üzenetekhez használ ideiglenes, páros azonosítókat, ami jobb névtelenséget és metaadat-védelmet biztosít.
+3. A P2P nem oldja meg a [MITM-támadás](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problémát, és a legtöbb létező implementáció nem használ sávon kívüli üzeneteket a kezdeti kulcscseréhez. A SimpleX a kezdeti kulcscseréhez sávon kívüli üzeneteket, vagy bizonyos esetekben már meglévő biztonságos és megbízható kapcsolatokat használ.
+4. A P2P-megvalósításokat egyes internetszolgáltatók blokkolhatják (mint például a [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). A SimpleX átvitel-független — a szabványos webes protokollokon, például WebSocketsen keresztül is működik.
+5. Minden ismert P2P-hálózat sebezhető [Sybil támadással](https://en.wikipedia.org/wiki/Sybil_attack), mert minden egyes csomópont felderíthető, és a hálózat egészként működik. A támadások enyhítésére szolgáló ismert intézkedés lehet egy központi kiszolgáló (például: tracker), vagy egy drága [tanúsítvány](https://en.wikipedia.org/wiki/Proof_of_work). A SimpleX hálózat nem ismeri fel a kiszolgálókat, töredezett és több elszigetelt alhálózatként működik, ami lehetetlenné teszi az egész hálózatra kiterjedő támadásokat.
+6. A P2P-hálózatok sebezhetőek lehetnek a [DRDoS-támadással](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) szemben, amikor a kliensek képesek a forgalmat újraközvetíteni és felerősíteni, ami az egész hálózatra kiterjedő szolgáltatásmegtagadást eredményez. A SimpleX kliensek csak az ismert kapcsolatokból származó forgalmat továbbítják, és a támadó nem használhatja őket arra, hogy az egész hálózatban felerősítse a forgalmat.
+
+---
+
+### A föderált hálózatokkal ellentétben
+
+A SimpleX átjátszó kiszolgálói NEM tárolnak felhasználói profilokat, kapcsolatokat és kézbesített üzeneteket, NEM kapcsolódnak egymáshoz, és NINCS kiszolgálójegyzék.
+
+---
+
+### SimpleX hálózat
+
+a kiszolgálók egyirányú várólistákat biztosítanak a felhasználók összekapcsolásához, de nem látják a hálózati kapcsolati gráfot; azt csak a felhasználók látják.
+
+## A SimpleX bemutatása
+
+1. Felhasználói élmény
+
+2. Hogyan működik
+
+3. Mit látnak a kiszolgálók
+
+1. Felhasználói élmény
+
+Csoportokat hozhat létre, valamint kétirányú beszélgetéseket folytathat a partnereivel, ugyanúgy mint bármely más üzenetváltó alkalmazásban.
+
+Hogyan működhet egyirányú várólistával és felhasználói profilazonosítók nélkül?
+
+2. Hogyan működik
+
+Minden kapcsolathoz két különböző üzenetküldési várólistát használ a különböző kiszolgálókon keresztül történő üzenetküldéshez és -fogadáshoz.
+
+A kiszolgálók csak egyetlen irányba továbbítják az üzeneteket, anélkül, hogy teljes képet kapnának a felhasználók beszélgetéseiről vagy kapcsolatairól.
+
+3. Mit látnak a kiszolgálók
+
+A kiszolgálók minden egyes várólistához külön névtelen hitelesítő-adatokkal rendelkeznek, és nem tudják, hogy melyik felhasználóhoz tartoznak.
+
+A felhasználók tovább fokozhatják a metaadatok védelmét, ha a Tor hálózat használatával férnek hozzá a kiszolgálókhoz, így megakadályozva az IP-cím szerinti korrelációt.
+
+## Összehasonlítás más protokollokkal
+
+|  |  | Signal, és a nagy platformok | XMPP, Matrix | P2P-protokollok |
+| --- | --- | --- | --- | --- |
+| Globális személyazonosságot igényel | Nem - privát | Igen [1] | Igen [2] | Igen [3] |
+| A MITM lehetősége | Nem - biztonságos [4] | Igen [5] | Igen | Igen |
+| Függés a DNS-től | Nem - ellenálló | Igen | Igen | Nem |
+| Egyetlen vagy központosított hálózat | Nem - decentralizált | Igen | Nem - föderált [6] | Igen [7] |
+| Központi komponens vagy más hálózati szintű támadás | Nem - ellenálló | Igen | Igen [2] | Igen [8] |
+
+---
+
+1. Általában telefonszám alapján, néhány esetben felhasználónév alapján
+2. DNS-alapú címek
+3. Nyilvános kulcs vagy más globális egyedi azonosító
+4. A SimpleX átjátszói nem veszélyeztethetik a végpontok közötti titkosítást. Ellenőrizze a biztonsági kódot a sávon kívüli csatorna elleni támadások veszélyeinek csökkentésére
+5. Ha az üzemeltetett kiszolgálók veszélybe kerülnek. Ellenőrizze a biztonsági kódot a Signal vagy más biztonságos üzenetküldő alkalmazás segítségével a támadások veszélyeinek csökkentésére
+6. Nem védi a felhasználók metaadatait
+7. Bár a P2P elosztott, de nem föderált — egyetlen hálózatként működnek
+8. A P2P-hálózatoknak vagy van egy központi hitelesítője, vagy az egész hálózat kompromittálódhat — [tekintse meg itt](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## A végpontok közötti titkosítás összehasonlítása más üzenetváltó alkalmazásokkal
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Tartalomkitöltés | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Letagadhatóság | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Kompromittálás előtti titkosságvédelem | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Kompromittálás utáni titkosságvédelem | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Kétlépcsős kulcscsere | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Kvantumbiztos, hibrid kriptográfia | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. A Briar 1024 bájtra, a Signal pedig 160 bájtra kerekítve tölti ki az üzenetek tartalmát
+2. A letagadhatóság nem foglalja magába a kliens és a kiszolgáló közötti kapcsolatot.
+3. Úgy tűnik, hogy a kriptográfiai aláírások használata rontja a letagadhatóságot, de ez tisztázásra szorul.
+4. A többeszközös megvalósítás rontja a dupla racsni kompromittálás utáni biztonságát — [tekintse meg itt](https://eprint.iacr.org/2021/626.pdf).
+5. A kétlépcsős kulcscsere nem követelmény a biztonsági kód ellenőrzéséhez.
+6. A kvantumbiztos kulcscsere „ritka” — csak a racsnis lépések egy részét védi.
diff --git a/hu/messaging/index.html b/hu/messaging/index.html
index d5521ccd9d..bd4224395f 100644
--- a/hu/messaging/index.html
+++ b/hu/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Teljes magánéletet élvezhet</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Véd a kéretlen tartalmaktól<br>és a visszaélésektől</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">A saját adatai felett rendelkezhet</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">A felhasználóké a SimpleX hálózat</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Lehetővé teszi az üzenetek felhasználói profilazonosítók nélküli kézbesítését, ami az alternatíváknál jobb metaadat-védelmet biztosít.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ennek megakadályozása érdekében a SimpleX alkalmazások egyszeri kulcsokat adnak át sávon kívül, amikor egy címet hivatkozásként vagy QR-kódként oszt meg.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox minden egyes várólistához, hogy megakadályozza a forgalom korrelációját az üzenetek várólistái között, ha a TLS veszélybe kerül.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ha bármilyen üzenetet hozzáadnak, eltávolítanak vagy módosítanak, a címzett értesítést kap róla.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Kiegészítő kiszolgálótitkosítási réteg a címzettnek történő kézbesítéshez, hogy megakadályozza a fogadott és az elküldött kiszolgálóforgalom közötti korrelációt, ha a TLS veszélybe kerül.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">A SimpleX kiszolgálók alacsony késleltetésű keverési csomópontokként működnek — a bejövő és kimenő üzenetek sorrendje eltérő.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Az újrakapcsolódás le van tiltva a munkamenet elleni támadások megelőzése érdekében.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">A SimpleX, Tor hálózaton keresztüli használatához telepítse az <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot alkalmazást</a> és engedélyezze a SOCKS5 proxyt (vagy a VPN-t <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">az iOS-ban</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Kevesebb támadási felülettel rendelkezik, mint a hagyományos üzenetváltó alkalmazások, és kevesebb metaadatot tesz elérhetővé.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">A kiszolgálók és a hálózatot megfigyelők számára a különböző méretű üzenetek egyformának tűnnek.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/old/index.html b/hu/old/index.html
index 3353b5b5b0..c364eae852 100644
--- a/hu/old/index.html
+++ b/hu/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">Újraértelmezett adatvédelem</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -749,10 +754,10 @@ window.addEventListener('click',(e)=>{
     Sok felhasználó kérdezte: <em>ha a SimpleXnek nincsenek felhasználói azonosítói, honnan tudja, hogy hová kell eljuttatni az üzeneteket?</em>
 </p>
 <p>
-    Az üzenetek kézbesítéséhez az összes többi hálózat által használt felhasználói azonosítók helyett a SimpleX az üzenetek várólistába rendezéséhez ideiglenes, névtelen, páros azonosítókat használ, külön-külön minden egyes kapcsolathoz — nincsenek hosszú távú azonosítók.
+    Az üzenetek kézbesítéséhez az összes többi hálózat által használt felhasználói azonosítók helyett a SimpleX az üzenetek várólistába rendezéséhez ideiglenes, névtelen, páros azonosítókat használ, külön-külön minden egyes kapcsolathoz &mdash; nincsenek hosszú távú azonosítók.
 </p>
 <p>
-    Meghatározhatja, hogy melyik kiszolgáló(ka)t használja az üzenetek fogadására, a partnereihez — azokat a kiszolgálókat, amelyeket az üzenetek küldésére használ. Minden beszélgetés két különböző kiszolgálót használ.
+    Meghatározhatja, hogy melyik kiszolgáló(ka)t használja az üzenetek fogadására, a partnereihez &mdash; azokat a kiszolgálókat, amelyeket az üzenetek küldésére használ. Minden beszélgetés két különböző kiszolgálót használ.
 </p>
 <p>
     Ez a kialakítás megakadályozza a felhasználók metaadatainak kiszivárgását az alkalmazás szintjén. Az adatvédelem további javítása és az IP-cím védelme érdekében az üzenetküldő kiszolgálókhoz Tor hálózaton keresztül is kapcsolódhat.
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">A SimpleX számítógépes alkalmazásának <a href="/downloads">letöltése</a></p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -932,7 +937,7 @@ window.addEventListener('click',(e)=>{
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
         <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Miért <span class="gradient-text">számít</span> az adatvédelem</h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">A metaadatok — <span class="text-active-blue">például, hogy kivel beszélget</span> — védelmének megőrzése biztonságot nyújt a következők ellen:</p>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">A metaadatok &mdash; <span class="text-active-blue">például, hogy kivel beszélget</span> &mdash; védelmének megőrzése biztonságot nyújt a következők ellen:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     Az online kiskereskedők tudják, hogy az alacsonyabb jövedelműek nagyobb valószínűséggel vásárolnak azonnal, ezért magasabb árakat számíthatnak fel, vagy eltörölhetik a kedvezményeket.
 </p>
 <p>
-    Egyes pénzügyi és biztosítótársaságok szociális grafikonokat használnak a kamatlábak és a díjak meghatározásához. Ez gyakran arra készteti az alacsonyabb jövedelmű embereket, hogy többet fizessenek — ez az úgynevezett <a href="https://fairbydesign.com/povertypremium/" target="_blank">„szegénységi prémium”</a>.
+    Egyes pénzügyi és biztosítótársaságok szociális grafikonokat használnak a kamatlábak és a díjak meghatározásához. Ez gyakran arra készteti az alacsonyabb jövedelmű embereket, hogy többet fizessenek &mdash; ez az úgynevezett <a href="https://fairbydesign.com/povertypremium/" target="_blank">„szegénységi prémium”</a>.
 </p>
 <p>
     A SimpleX hálózat minden alternatívánál jobban védi a kapcsolatai adatait, teljes mértékben megakadályozva, hogy az ismeretségi-hálója bármilyen vállalat vagy szervezet számára elérhetővé váljon. Még ha az emberek a SimpleX Chat által előre beállított kiszolgálókat is használják, sem az alkalmazások, sem a kiszolgálók üzemeltetői nem ismerik, sem felhasználók számát, sem a kapcsolataikat.
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1045,7 +1050,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Mindenkinek törődnie kell a magánélet és a kommunikáció biztonságával — az ártalmatlan beszélgetések veszélybe sodorhatják, még akkor is, ha nincs semmi rejtegetnivalója.
+    Mindenkinek törődnie kell a magánélet és a kommunikáció biztonságával &mdash; az ártalmatlan beszélgetések veszélybe sodorhatják, még akkor is, ha nincs semmi rejtegetnivalója.
 </p>
 <p>
     Az egyik legmegdöbbentőbb a <a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">Mohamedou Ould Salahi</a> memoárjában leírt és az „A mauritániai” c. filmben bemutatott történet. Őt bírósági tárgyalás nélkül a guantánamói táborba zárták, és ott kínozták 15 éven át, miután egy afganisztáni rokonát telefonon felhívta, akit azzal gyanúsítottak a hatóságok, hogy köze van a 9/11-es merényletekhez, holott Salahi az előző 10 évben Németországban élt.
@@ -1054,7 +1059,7 @@ window.addEventListener('click',(e)=>{
     Átlagos embereket letartóztatnak azért, amit online megosztanak, még „névtelen” fiókjaikon keresztül is, <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html" target="_blank">még demokratikus országokban is</a>.
 </p>
 <p>
-    Nem elég csak egy végpontok között titkosított üzenetváltó alkalmazást használnunk, mindannyiunknak olyan üzenetváltó alkalmazásokat kell használnunk, amelyek védik a személyes partnereink magánéletét — akikkel kapcsolatban állunk.
+    Nem elég csak egy végpontok között titkosított üzenetváltó alkalmazást használnunk, mindannyiunknak olyan üzenetváltó alkalmazásokat kell használnunk, amelyek védik a személyes partnereink magánéletét &mdash; akikkel kapcsolatban állunk.
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Teljes magánéletet élvezhet</h3>
                             </div>
 
@@ -1109,7 +1114,7 @@ window.addEventListener('click',(e)=>{
     A SimpleX megvédi a profilhoz tartozó partnereket és azok metaadatait is, elrejtve azokat a SimpleX hálózat kiszolgálói és a megfigyelők elől.
 </p>
 <p>
-    Minden más létező üzenetküldő hálózattól eltérően a SimpleX nem rendelkezik a felhasználókhoz rendelt azonosítókkal — <strong>még véletlenszerű számokkal sem</strong>.
+    Minden más létező üzenetküldő hálózattól eltérően a SimpleX nem rendelkezik a felhasználókhoz rendelt azonosítókkal &mdash; <strong>még véletlenszerű számokkal sem</strong>.
 </p>
 
                                     </div>
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">További tudnivalók</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Tudnivalók elrejtése</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Véd a kéretlen tartalmaktól<br>és a visszaélésektől</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">További tudnivalók</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Tudnivalók elrejtése</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">A saját adatai felett rendelkezhet</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    A SimpleX Chat az összes felhasználói adatot kizárólag a klienseken tárolja egy <strong>hordozható titkosított adatbázis-formátumban</strong> —, amely exportálható és átvihető bármely más támogatott eszközre.
+    A SimpleX Chat az összes felhasználói adatot kizárólag a klienseken tárolja egy <strong>hordozható titkosított adatbázis-formátumban</strong> &mdash;, amely exportálható és átvihető bármely más támogatott eszközre.
 </p>
 <p>
     A végpontok között titkosított üzenetek átmenetileg a SimpleX átjátszóin tartózkodnak, amíg be nem érkeznek a címzetthez, majd automatikusan véglegesen törlődnek onnan.
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">További tudnivalók</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Tudnivalók elrejtése</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">A felhasználóké a SimpleX hálózat</h3>
                             </div>
 
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">További tudnivalók</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Tudnivalók elrejtése</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1320,7 +1325,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Más üzenetküldő hálózatoktól eltérően a SimpleX <strong>nem rendel azonosítókat a felhasználókhoz</strong>. Nem támaszkodik telefonszámokra, tartomány-alapú címekre (mint az e-mail, XMPP vagy a Matrix), felhasználónevekre, nyilvános kulcsokra vagy akár véletlenszerű számokra a felhasználók azonosításához — a SimpleX kiszolgálók üzemeltetői nem tudják, hogy hányan használják a kiszolgálóikat.
+    Más üzenetküldő hálózatoktól eltérően a SimpleX <strong>nem rendel azonosítókat a felhasználókhoz</strong>. Nem támaszkodik telefonszámokra, tartomány-alapú címekre (mint az e-mail, XMPP vagy a Matrix), felhasználónevekre, nyilvános kulcsokra vagy akár véletlenszerű számokra a felhasználók azonosításához &mdash; a SimpleX kiszolgálók üzemeltetői nem tudják, hogy hányan használják a kiszolgálóikat.
 </p>
 <p>
     Az üzenetek kézbesítéséhez a SimpleX egyirányú várólistákat használ az üzenetekhez, <a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">páronkénti, névtelen címekkel</a>, külön a fogadott és külön az elküldött üzenetekhez, általában különböző kiszolgálókon keresztül.
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     A föderált hálózatok kiszolgálóitól (e-mail, XMPP vagy Matrix) eltérően a SimpleX kiszolgálók nem tárolják a felhasználói fiókokat, csak továbbítják az üzeneteket, így védve mindkét fél magánéletét.
 </p>
 <p>
-    A küldött és a fogadott kiszolgálóforgalom között nincsenek közös azonosítók vagy titkosított szövegek — ha bárki megfigyeli, nem tudja könnyen megállapítani, hogy ki kivel kommunikál, még akkor sem, ha a TLS-t kompromittálják.
+    A küldött és a fogadott kiszolgálóforgalom között nincsenek közös azonosítók vagy titkosított szövegek &mdash; ha bárki megfigyeli, nem tudja könnyen megállapítani, hogy ki kivel kommunikál, még akkor sem, ha a TLS-t kompromittálják.
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Teljesen decentralizált — a SimpleX hálózat a felhasználóké</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Teljesen decentralizált &mdash; a SimpleX hálózat a felhasználóké</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     Használhatja <strong>a SimpleXet a saját kiszolgálóival</strong>, és továbbra is kommunikálhat azokkal, akik az előre beállított kiszolgálókat használják az alkalmazásban.
 </p>
 <p>
-    A SimpleX hálózat <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">nyitott protokollt</a> használ és <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK-t biztosít a csevegési botok létrehozásához</a>, lehetővé téve olyan szolgáltatások megvalósítását, amelyekkel a felhasználók a SimpleX Chat alkalmazásokon keresztül léphetnek kapcsolatba — mi már nagyon várjuk, hogy milyen SimpleX szolgáltatásokat készítenek a lelkes közreműködők.
+    A SimpleX hálózat <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">nyitott protokollt</a> használ és <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK-t biztosít a csevegési botok létrehozásához</a>, lehetővé téve olyan szolgáltatások megvalósítását, amelyekkel a felhasználók a SimpleX Chat alkalmazásokon keresztül léphetnek kapcsolatba &mdash; mi már nagyon várjuk, hogy milyen SimpleX szolgáltatásokat készítenek a lelkes közreműködők.
 </p>
 <p>
-    Ha a SimpleX hálózatra való fejlesztést fontolgatja, például a SimpleX alkalmazások felhasználóinak szánt csevegési botot, vagy a SimpleX Chat könyvtárbotjának integrálását más mobilalkalmazásba, <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">lépjen velünk kapcsolatba</a>, ha bármilyen tanácsot vagy támogatást szeretne kapni.
+    Ha a SimpleX hálózatra való fejlesztést fontolgatja, például a SimpleX alkalmazások felhasználóinak szánt csevegési botot, vagy a SimpleX Chat könyvtárbotjának integrálását más mobilalkalmazásba, <a href="https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">lépjen velünk kapcsolatba</a>, ha bármilyen tanácsot vagy támogatást szeretne kapni.
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított üzenetek markdown formázással és szerkesztéssel</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított<br>képek, videók és fájlok</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított, decentralizált csoportok — csak a felhasználók tudják, hogy ezek léteznek</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított, decentralizált csoportok &mdash; csak a felhasználók tudják, hogy ezek léteznek</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított hangüzenetek</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Eltűnő üzenetek</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Végpontok között titkosított<br>hang- és videóhívások</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Hordozható, titkosított alkalmazás-adattárolás — profil átköltöztetése egy másik eszközre</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Hordozható, titkosított alkalmazás-adattárolás &mdash; profil átköltöztetése egy másik eszközre</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Az inkognitómód —<br>egyedülálló a SimpleX Chatben</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Az inkognitómód &mdash;<br>egyedülálló a SimpleX Chatben</p>
             </div>
             
         </div>
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Ideiglenes, névtelen, páronkénti azonosítók</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Sávon kívüli<br>kulcscsere</h3>
@@ -1614,14 +1619,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Kétrétegű végpontok közötti titkosítás</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">Dupla racsnis protokoll —<br>OTR-üzenetküldés, kompromittálás előtti és utáni titkosság-védelemmel.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Dupla racsnis protokoll &mdash;<br>OTR-üzenetküldés, kompromittálás előtti és utáni titkosság-védelemmel.</p>
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox minden egyes várólistához, hogy megakadályozza a forgalom korrelációját az üzenetek várólistái között, ha a TLS veszélybe kerül.</p>
                             
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Üzenetintegritás<br>ellenőrzés</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">További rétege a<br>kiszolgáló-titkosítás</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Üzenetek keverése<br>a korreláció csökkentése érdekében</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">A SimpleX kiszolgálók alacsony késleltetésű keverési csomópontokként működnek — a bejövő és kimenő üzenetek sorrendje eltérő.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">A SimpleX kiszolgálók alacsony késleltetésű keverési csomópontokként működnek &mdash; a bejövő és kimenő üzenetek sorrendje eltérő.</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">Bezárás</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Biztonságos, hitelesített<br>TLS-adatátvitel</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Hozzáférés a Tor hálózaton keresztül<br>(nem kötelező)</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Egyirányú<br>várólista az üzenetekhez</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Többrétegű<br>tartalomkitöltés</h3>
@@ -1780,8 +1785,8 @@ window.addEventListener('click',(e)=>{
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">A P2P-hálózatokkal ellentétben</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         Minden üzenet a kiszolgálókon keresztül kerül elküldésre, ami jobb metaadat-védelmet és megbízható aszinkron üzenetkézbesítést biztosít, miközben elkerülhető a sok <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">a P2P-hálózatok problémái</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">Összehasonlítás más P2P-üzenetküldő protokollokkal</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1810,7 +1815,7 @@ window.addEventListener('click',(e)=>{
         A P2P nem oldja meg a <a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">MITM-támadás</a> problémát, és a legtöbb létező implementáció nem használ sávon kívüli üzeneteket a kezdeti kulcscseréhez. A SimpleX a kezdeti kulcscseréhez sávon kívüli üzeneteket, vagy bizonyos esetekben már meglévő biztonságos és megbízható kapcsolatokat használ.
     </li>
     <li>
-        A P2P-megvalósításokat egyes internetszolgáltatók blokkolhatják (mint például a <a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a>). A SimpleX átvitel-független — a szabványos webes protokollokon, például WebSocketsen keresztül is működik.
+        A P2P-megvalósításokat egyes internetszolgáltatók blokkolhatják (mint például a <a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a>). A SimpleX átvitel-független &mdash; a szabványos webes protokollokon, például WebSocketsen keresztül is működik.
     </li>
     <li>
         Minden ismert P2P-hálózat sebezhető <a href="https://en.wikipedia.org/wiki/Sybil_attack">Sybil támadással</a>, mert minden egyes csomópont felderíthető, és a hálózat egészként működik. A támadások enyhítésére szolgáló ismert intézkedés lehet egy központi kiszolgáló (például: tracker), vagy egy drága <a href="https://en.wikipedia.org/wiki/Proof_of_work">tanúsítvány</a>. A SimpleX hálózat nem ismeri fel a kiszolgálókat, töredezett és több elszigetelt alhálózatként működik, ami lehetetlenné teszi az egész hálózatra kiterjedő támadásokat.
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">A föderált hálózatokkal ellentétben</h3>
@@ -1862,8 +1867,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">SimpleX hálózat</h3>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. Felhasználói élmény</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Csoportokat hozhat létre, valamint kétirányú beszélgetéseket folytathat a partnereivel, ugyanúgy mint bármely más üzenetváltó alkalmazásban.
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. Hogyan működik</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Minden kapcsolathoz két különböző üzenetküldési várólistát használ a különböző kiszolgálókon keresztül történő üzenetküldéshez és -fogadáshoz.
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. Mit látnak a kiszolgálók</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             A kiszolgálók minden egyes várólistához külön névtelen hitelesítő-adatokkal rendelkeznek, és nem tudják, hogy melyik felhasználóhoz tartoznak.
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal, és a nagy platformok</th>
                         <th class="pb-4">XMPP, Matrix</th>
@@ -2111,7 +2116,7 @@ window.addEventListener("load", function () {
                     <li> A SimpleX átjátszói nem veszélyeztethetik a végpontok közötti titkosítást. Ellenőrizze a biztonsági kódot a sávon kívüli csatorna elleni támadások veszélyeinek csökkentésére</li>
                     <li> Ha az üzemeltetett kiszolgálók veszélybe kerülnek. Ellenőrizze a biztonsági kódot a Signal vagy más biztonságos üzenetküldő alkalmazás segítségével a támadások veszélyeinek csökkentésére</li>
                     <li> Nem védi a felhasználók metaadatait</li>
-                    <li> Bár a P2P elosztott, de nem föderált — egyetlen hálózatként működnek</li>
+                    <li> Bár a P2P elosztott, de nem föderált &mdash; egyetlen hálózatként működnek</li>
                     <li> A P2P-hálózatoknak vagy van egy központi hitelesítője, vagy az egész hálózat kompromittálódhat - <a class="underline text-primary-light dark:text-primary-dark underline-offset-2" href="https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols">tekintse meg itt</a></li>
                 </ol>
             </div>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Regisztráljon a hírleveleinkre, hogy ne maradjon le semmiről</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Adjon meg egy e-mail-címet">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">A SimpleX számítógépes alkalmazásának <a href="/downloads">letöltése</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/hu/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/hu/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/hu/why.md b/hu/why.md
new file mode 100644
index 0000000000..bf9e5c69a3
--- /dev/null
+++ b/hu/why.md
@@ -0,0 +1,19 @@
+# Fiók nélkül születtünk.
+
+Senki sem követte nyomon a beszélgetéseinket. Senki sem készített térképet arról, hogy merre jártunk. A magánéletünk nem csak egy funkció volt, hanem az életmódunk.
+
+Aztán felléptünk az internetre, és minden platform kért belőlünk egy darabot — nevet, telefonszámot, baráti kapcsolatokat. Elfogadtuk, hogy a kommunikáció ára az, hogy mások megtudják, hogy kivel beszélünk. Minden generáció, az emberek és a technológia is eddig így működött — telefon, e-mail, üzenetküldő programok, közösségi média. Úgy tűnt, ez az egyetlen lehetséges mód.
+
+De van egy másik lehetőség is. Egy hálózat, amelyben nincsenek telefonszámok. Nincsenek felhasználónevek. Nincsenek fiókok. Nincsenek semmiféle felhasználói azonosítók. Egy hálózat, amely összeköti az embereket és titkosított üzeneteket továbbít, anélkül, hogy tudná, ki csatlakozik hozzá.
+
+Nem egy jobb zár mások ajtaján. Nem egy kedvesebb házmester, aki tiszteletben tartja az Ön magánéletét, de mégis nyilvántartást vezet minden látogatójáról. Ön itt nem csak egy vendég. Ön itt otthon van. Nincs az a hatalom, amely beléphetne ide — Ön itt szuverén.
+
+A beszélgetései Önhöz tartoznak, ahogy az internet megjelenése előtt is mindig így volt. A hálózat nem egy hely, amelyet meglátogat. Ez egy olyan hely, amelyet Ön hoz létre saját magának. És senki sem veheti el Öntől, függetlenül attól, hogy privát vagy nyilvános.
+
+A legrégebbi emberi szabadság — beszélgetni az emberekkel, anélkül, hogy mások megfigyelnének — olyan infrastruktúrán alapul, amely nem tudja elárulni.
+
+Mert felszámoltuk a lehetőségét is annak, hogy megtudjuk, Ön kicsoda. Így az *önrendelkezése* soha nem kerülhet idegen kezekbe.
+
+Legyen szabad a saját hálózatában.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/hu/why/index.html b/hu/why/index.html
index c282a45a0c..fea5006490 100644
--- a/hu/why/index.html
+++ b/hu/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/hu/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Legyen szabad a saját hálózatában.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/id/contact.md b/id/contact.md
new file mode 100644
index 0000000000..990051c753
--- /dev/null
+++ b/id/contact.md
@@ -0,0 +1,66 @@
+# Anda menerima alamat untuk terhubung di SimpleX Chat
+
+## Pindai kode QR dengan aplikasi SimpleX Chat di ponsel atau tablet Anda.
+
+Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirimkan melalui jaringan saat Anda melihat halaman ini — kunci tersebut terdapat dalam fragmen hash URL tautan.
+
+Belum unduh SimpleX Chat?
+
+Gunakan tautan di bawah untuk unduh aplikasi.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Pindai kode QR dari aplikasi seluler
+
+# Anda menerima alamat untuk terhubung di SimpleX Chat
+
+Untuk membuat koneksi:
+
+Instal aplikasi SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid)
+
+1
+
+Hubungkan di aplikasi
+
+Buka aplikasi SimpleX
+
+2
+
+Ketuk tombol "connect" di aplikasi
+
+3
+
+## Pindai kode QR dengan aplikasi SimpleX Chat
+
+Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini —
+keduanya terdapat dalam fragmen hash URL tautan.
+
+## Menginstal SimpleX Chat ke terminal
+
+Gunakan perintah ini:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Lihat SimpleX Chat Repositori GitHub untuk petunjuk cara mengunduh atau mengompilasinya dari kode sumber.
+
+---
+
+## Jika Anda sudah menginstal SimpleX Chat untuk terminal
+
+Jika Anda sudah menginstal SimpleX Chat untuk terminal v1.0.0+, salin perintah di bawah ini dan gunakan dalam obrolan:
+
+## Gabung SimpleX
+
+Kami mengundang Anda untuk gabung ke percakapan
+
+[Bergabung dengan komunitas REDDIT](https://www.reddit.com/r/SimpleXChat/) [Gabung dengan kami di GitHub](https://github.com/simplex-chat) [Donasi untuk bantu kami](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Daftar untuk menerima pembaruan kami
+
+---
+
+Dapatkan [aplikasi desktop](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid)
diff --git a/id/contact/index.html b/id/contact/index.html
index 9efb197680..076db12392 100644
--- a/id/contact/index.html
+++ b/id/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Anda menerima alamat untuk terhubung di SimpleX Chat</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Gunakan tautan di bawah untuk unduh aplikasi.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instal aplikasi SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Pindai kode QR dengan aplikasi SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini —<br> keduanya terdapat dalam fragmen hash URL tautan.
+                            Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini &mdash;<br> keduanya terdapat dalam fragmen hash URL tautan.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Menginstal SimpleX Chat ke terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositori GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jika Anda sudah menginstal SimpleX Chat untuk terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Daftar untuk menerima pembaruan kami</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Masukkan alamat email Anda">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Dapatkan <a href="/downloads">aplikasi desktop</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/id/fdroid.md b/id/fdroid.md
new file mode 100644
index 0000000000..ce3c76a4af
--- /dev/null
+++ b/id/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat melalui F-Droid
+
+### Repo SimpleX Chat
+
+Versi stable dan beta yang dibuat oleh pengembang
+
+Untuk menambahkannya ke klien F-Droid Anda, pindai kode QR atau gunakan URL ini:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Penandatanganan sidikjari kunci (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Repo F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Versi stable yang dibuat oleh F-Droid.org
+
+Rilisan ke repo ini dilakukan beberapa hari kemudian.
+
+Repositori SimpleX Chat dan F-Droid.org menandatangani build dengan kunci yang berbeda. Untuk beralih, silakan [ekspor](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) basis data chat dan pasang ulang aplikasi.
diff --git a/id/fdroid/index.html b/id/fdroid/index.html
index 6017cf54f3..9ce2e3309f 100644
--- a/id/fdroid/index.html
+++ b/id/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat melalui F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Versi stable dan beta yang dibuat oleh pengembang</p>
                         <p>Untuk menambahkannya ke klien F-Droid Anda, <span class="hide-on-mobile">pindai kode QR atau</span> gunakan URL ini:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Penandatanganan sidikjari kunci (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Repo F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Versi stable yang dibuat oleh F-Droid.org</p>
                 <p class="mb-2">Rilisan ke repo ini dilakukan beberapa hari kemudian.</p>
                 <p class="mb-2">Repositori SimpleX Chat dan F-Droid.org menandatangani build dengan kunci yang berbeda. Untuk beralih, silakan <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">ekspor</a> basis data chat dan pasang ulang aplikasi.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/id/file.md b/id/file.md
new file mode 100644
index 0000000000..ea1ed1b14e
--- /dev/null
+++ b/id/file.md
@@ -0,0 +1,31 @@
+# Transfer File SimpleX
+
+Seret & lepas file di sini
+
+atau
+
+Pilih file
+
+Maks. 100 MB - [aplikasi SimpleX Chat](https://simplex.chat/downloads) mendukung file hingga 1 GB
+
+Kirim file dengan aman menggunakan enkripsi end-to-end — tanpa akun, tanpa pelacakan.
+
+## Dapatkan SimpleX Chat — messenger paling aman & privat
+
+Transfer file yang baru saja Anda gunakan memakai protokol perutean data yang sama dengan SimpleX Chat. Aplikasi ini memiliki pesan terenkripsi end-to-end, panggilan suara dan video, grup, serta pengiriman file. Tanpa akun. Tanpa telepon. Tanpa email. Tanpa ID profil pengguna.
+
+# Protokol XFTP: transfer file paling aman
+
+### Tidak memerlukan akun
+
+Setiap fragmen file menggunakan kunci acak baru. Router data tidak memiliki "pengguna" atau "file" - mereka mentransfer fragmen file terenkripsi dengan ukuran tetap.
+
+### Dienkripsi tiga lapis di browser Anda
+
+Kunci enkripsi file hanya ada di fragmen hash URL - browser Anda tidak pernah mengirimkannya ke server. Ada 3 lapisan enkripsi: transport TLS, enkripsi per penerima (kunci ephemeral unik untuk setiap transfer), dan enkripsi file end-to-end.
+
+### Router data independen
+
+Saat file dipecah menjadi fragmen, file tersebut dikirim melalui router jaringan yang dioperasikan oleh pihak independen. Tidak ada operator yang dapat melihat ukuran atau nama file yang sebenarnya. Bahkan jika sebuah router dikompromikan, router itu hanya dapat melihat fragmen terenkripsi berukuran tetap. Fragmen file di-cache oleh router jaringan selama sekitar 48 jam.
+
+[Baca spesifikasi protokol XFTP →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/id/file/index.html b/id/file/index.html
index 27e5213c66..6e66d20c22 100644
--- a/id/file/index.html
+++ b/id/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,10 +665,10 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">Transfer File SimpleX</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
-          <p>Seret &amp; lepas file di sini</p>
+          <p>Seret & lepas file di sini</p>
           <p class="hint">atau</p>
           <span class="btn">Pilih file</span>
           <p class="hint">Maks. 100 MB - <a href="/downloads">aplikasi SimpleX Chat</a> mendukung file hingga 1 GB</p>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Dapatkan SimpleX Chat — messenger paling aman &amp; privat
+      Dapatkan SimpleX Chat &mdash; messenger paling aman &amp; privat
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       Transfer file yang baru saja Anda gunakan memakai protokol perutean data yang sama dengan SimpleX Chat. Aplikasi ini memiliki pesan terenkripsi end-to-end, panggilan suara dan video, grup, serta pengiriman file. Tanpa akun. Tanpa telepon. Tanpa email. Tanpa ID profil pengguna.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/id/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/id/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
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@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
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-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/id/index.html b/id/index.html
index 320e8c27d5..ec6758b1c6 100644
--- a/id/index.html
+++ b/id/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/id/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/id/fdroid" title="Aplikasi SimpleX via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Pratinjau iOS publik di TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Pratinjau iOS publik di TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Audit Keamanan" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Sekarang</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/id/index.md b/id/index.md
new file mode 100644
index 0000000000..479b770e08
--- /dev/null
+++ b/id/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Bebaslah
+
+## Di Jaringan Anda
+
+Jaringan pertama tanpa ID pengguna.
+Anda pemilik kontak, grup, dan kanal Anda.
+
+Invest in SimpleX Chat. [Lebih lanjut.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [Aplikasi SimpleX via F-Droid](https://simplex.chat/id/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Audit Keamanan](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Audit
+Keamanan
+
+[Rekomendasi messenger Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Rekomendasi perpesanan Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publikasi Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Ulasan oleh Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Wawancara podcast OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Tidak Ada yang Bisa Melihat dengan Siapa Anda Bicara
+
+Bahkan server pun tidak bisa – semua pesan terlihat seperti derau acak.
+
+Puluhan juta pesan dikirim secara privat setiap hari.
+
+[Pelajari lebih lanjut tentang perpesanan SimpleX](https://simplex.chat/id/messaging)
+
+## Anda Pemilik Jaringannya
+
+Setiap kontak dan grup ada di perangkat Anda, bukan di basis data server.
+
+Tidak ada satu entitas pun yang mengendalikan jaringan – siapa saja bisa menjalankan server.
+
+[Mengapa kami membangunnya](https://simplex.chat/id/why)
+
+## Didanai oleh Penggunanya
+
+Untuk tetap independen, kanal dan komunitas besar akan membayar server mereka.
+
+Dan pengguna sekarang bisa berinvestasi di SimpleX Chat — crowdfunding kini aktif!
+
+[Investasi di SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap Menuju Internet Bebas
+
+2026
+
+: Skala ke Komunitas Besar
+
+Menghindari platform terpusat
+
+Jun 2027
+
+: Komunitas & Server Berkelanjutan
+
+Peluncuran Kredit Komunitas
+
+Des 2027
+
+: Buat Komunitas Anda Meningkat
+
+Alat untuk promosikan komunitas Anda
+
+[Grup pengguna SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Gabung ke Komunitas SimpleX
+
+Lebih dari 2 juta orang telah mengunduh aplikasi SimpleX.
+
+Temukan kanal dan komunitas Anda di direktori dan buat milik Anda sendiri!
+
+[Lihat Direktori SimpleX](https://simplex.chat/directory)
diff --git a/id/invitation.md b/id/invitation.md
new file mode 100644
index 0000000000..9ec3d79b17
--- /dev/null
+++ b/id/invitation.md
@@ -0,0 +1,66 @@
+# Anda menerima tautan 1 kali untuk terhubung di SimpleX Chat
+
+## Pindai kode QR dengan aplikasi SimpleX Chat di ponsel atau tablet Anda.
+
+Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirimkan melalui jaringan saat Anda melihat halaman ini — kunci tersebut terdapat dalam fragmen hash URL tautan.
+
+Belum unduh SimpleX Chat?
+
+Gunakan tautan di bawah untuk unduh aplikasi.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Pindai kode QR dari aplikasi seluler
+
+# Anda menerima tautan 1 kali untuk terhubung di SimpleX Chat
+
+Untuk membuat koneksi:
+
+Instal aplikasi SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid)
+
+1
+
+Hubungkan di aplikasi
+
+Buka aplikasi SimpleX
+
+2
+
+Ketuk tombol "connect" di aplikasi
+
+3
+
+## Pindai kode QR dengan aplikasi SimpleX Chat
+
+Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini —
+keduanya terdapat dalam fragmen hash URL tautan.
+
+## Menginstal SimpleX Chat ke terminal
+
+Gunakan perintah ini:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Lihat SimpleX Chat Repositori GitHub untuk petunjuk cara mengunduh atau mengompilasinya dari kode sumber.
+
+---
+
+## Jika Anda sudah menginstal SimpleX Chat untuk terminal
+
+Jika Anda sudah menginstal SimpleX Chat untuk terminal v1.0.0+, salin perintah di bawah ini dan gunakan dalam obrolan:
+
+## Gabung SimpleX
+
+Kami mengundang Anda untuk gabung ke percakapan
+
+[Bergabung dengan komunitas REDDIT](https://www.reddit.com/r/SimpleXChat/) [Gabung dengan kami di GitHub](https://github.com/simplex-chat) [Donasi untuk bantu kami](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Daftar untuk menerima pembaruan kami
+
+---
+
+Dapatkan [aplikasi desktop](https://simplex.chat/downloads) SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/id/fdroid)
diff --git a/id/invitation/index.html b/id/invitation/index.html
index 01a48e16e1..e17a6e6998 100644
--- a/id/invitation/index.html
+++ b/id/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Anda menerima tautan 1 kali untuk terhubung di SimpleX Chat</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Gunakan tautan di bawah untuk unduh aplikasi.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instal aplikasi SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Pindai kode QR dengan aplikasi SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini —<br> keduanya terdapat dalam fragmen hash URL tautan.
+                            Kunci publik dan alamat antrean pesan dalam tautan ini TIDAK dikirim melalui jaringan saat Anda melihat halaman ini &mdash;<br> keduanya terdapat dalam fragmen hash URL tautan.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Menginstal SimpleX Chat ke terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositori GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jika Anda sudah menginstal SimpleX Chat untuk terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Daftar untuk menerima pembaruan kami</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Masukkan alamat email Anda">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Dapatkan <a href="/downloads">aplikasi desktop</a> SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/id/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/id/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/id/messaging.md b/id/messaging.md
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--- /dev/null
+++ b/id/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Mengapa SimpleX unik
+
+### Anda memiliki privasi penuh
+
+SimpleX melindungi privasi profil, kontak, dan metadata Anda, menyembunyikannya dari server jaringan SimpleX dan pengamat mana pun.
+
+Tidak seperti jaringan perpesanan lain yang ada, SimpleX tidak memiliki ID tetap kepada pengguna — **bahkan nomor acak**.
+
+### Anda terlindungi dari spam dan penyalahgunaan
+
+Karena Anda tidak memiliki ID atau alamat tetap di jaringan SimpleX, tidak seorang pun dapat menghubungi Anda kecuali Anda membagikan alamat pengguna 1-kali atau sementara, seperti kode QR atau tautan.
+
+### Data Anda kendali Anda
+
+SimpleX menyimpan semua data pengguna pada perangkat klien dalam **format basis data terenkripsi portabel** — data tersebut dapat ditransfer ke perangkat lain.
+
+Pesan yang dienkripsi end-to-end disimpan sementara di server relay SimpleX hingga diterima, lalu dihapus secara permanen.
+
+### Anda memiliki jaringan SimpleX
+
+Jaringan SimpleX sepenuhnya terdesentralisasi dan independen dari crypto-currency atau jaringan lain apa pun, selain Internet.
+
+Anda dapat **menggunakan SimpleX dengan server Anda sendiri** atau dengan server yang disediakan oleh kami — dan tetap terhubung dengan pengguna mana pun.
+
+# Privasi penuh atas identitas, profil, kontak, dan metadata Anda
+
+Berbeda dengan jaringan perpesanan lainnya, SimpleX **tidak memiliki ID tetap kepada pengguna**. SimpleX tidak bergantung pada nomor telepon, alamat berbasis domain (seperti email atau XMPP), nama pengguna, kunci publik, atau bahkan angka acak untuk mengidentifikasi penggunanya — operator server SimpleX tidak tahu berapa banyak orang yang menggunakan server mereka.
+
+Untuk menyampaikan pesan, SimpleX menggunakan [alamat anonim penghubung](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) dari antrean pesan searah, terpisah untuk pesan yang diterima dan dikirim, biasanya melalui server yang berbeda.
+
+Desain ini melindungi privasi orang yang Anda ajak berkomunikasi, menyembunyikannya dari server jaringan SimpleX dan dari pengamat mana pun. Untuk menyembunyikan alamat IP Anda dari server, Anda dapat **terhubung ke server SimpleX melalui Tor**.
+
+# Perlindungan terbaik dari spam dan penyalahgunaan
+
+Karena Anda tidak memiliki ID di jaringan SimpleX, tidak seorang pun dapat menghubungi Anda kecuali Anda membagikan alamat pengguna 1-kali atau sementara, seperti kode QR atau tautan.
+
+Bahkan dengan alamat pengguna opsional, meskipun dapat digunakan untuk mengirim permintaan kontak spam, Anda dapat mengubah atau menghapusnya sepenuhnya tanpa kehilangan koneksi apa pun.
+
+# Kepemilikan, kontrol, dan keamanan data Anda
+
+SimpleX Chat menyimpan semua data pengguna hanya pada perangkat klien menggunakan **format basis data terenkripsi portabel** yang dapat diekspor dan ditransfer ke perangkat apa pun yang didukung.
+
+Pesan yang dienkripsi end-to-end disimpan sementara di server relay SimpleX hingga diterima, lalu dihapus secara permanen.
+
+Tidak seperti server jaringan terfederasi (email, XMPP atau Matrix), server SimpleX tidak menyimpan akun pengguna, mereka hanya menyampaikan pesan, melindungi privasi kedua belah pihak.
+
+Tidak ada pengenal atau teks sandi yang sama antara lalu lintas server yang dikirim dan diterima — jika ada orang yang mengamatinya, mereka tidak dapat dengan mudah menentukan siapa yang berkomunikasi dengan siapa, bahkan jika TLS disusupi.
+
+# Sepenuhnya terdesentralisasi — pengguna memiliki jaringan SimpleX
+
+Anda dapat **menggunakan SimpleX dengan server Anda sendiri** dan tetap berkomunikasi dengan orang yang menggunakan server yang dikonfigurasikan sebelumnya dalam aplikasi.
+
+Jaringan SimpleX menggunakan [protokol terbuka](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) dan menyediakan [SDK untuk membuat bot obrolan](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), yang memungkinkan penerapan layanan yang dapat berinteraksi dengan pengguna melalui aplikasi SimpleX Chat — kami benar-benar menantikan untuk melihat layanan SimpleX apa yang akan Anda buat.
+
+Jika Anda mempertimbangkan pengembangan untuk jaringan SimpleX, misalnya, bot obrolan untuk pengguna aplikasi SimpleX, atau integrasi pustaka Obrolan SimpleX ke dalam aplikasi seluler Anda, silakan [hubungi kami](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) untuk saran dan dukungan apa pun.
+
+## Fitur
+
+Pesan terenkripsi E2E dengan markdown dan pengeditan
+
+Gambar, video, dan berkas
+terenkripsi E2E
+
+Grup terenkripsi E2E yang terdesentralisasi — hanya pengguna yang tahu keberadaannya
+
+Pesan suara terenkripsi E2E
+
+Pesan menghilang
+
+Panggilan suara dan video
+terenkripsi E2E
+
+Penyimpanan aplikasi terenkripsi portabel — pindahkan profil ke perangkat lain
+
+Mode penyamaran —
+unik untuk SimpleX Chat
+
+## Apa yang membuat SimpleX privat
+
+### Pengidentifikasi berpasangan anonim sementara
+
+SimpleX menggunakan alamat terhubung anonim sementara dan kredensial untuk setiap kontak pengguna atau anggota grup.
+
+Fitur ini mengirim pesan tanpa identifikasi profil pengguna, memberikan privasi metadata lebih baik daripada alternatif lainnya.
+
+### Pertukaran kunci out-of-band
+
+Banyak jaringan komunikasi yang rentan terhadap serangan MITM oleh server atau penyedia jaringan.
+
+Untuk mencegahnya, aplikasi SimpleX meneruskan kunci 1-kali di luar jalur, saat bagikan alamat sebagai tautan atau kode QR.
+
+### 2 lapisan enkripsi end-to-end
+
+Protokol double-ratchet —
+Pesan OTR dengan perfect forward secrecy dan pemulihan pembobolan.
+
+Kotak kripto NaCL di setiap antrean untuk mencegah korelasi lalu lintas antara antrean pesan jika TLS disusupi.
+
+### Verifikasi integritas pesan
+
+Untuk menjamin integritas, pesan diberi nomor urut dan menyertakan hash dari pesan sebelumnya.
+
+Jika ada pesan yang ditambah, dihapus atau diubah, penerima akan diberi tahu.
+
+### Lapisan enkripsi tambahan server
+
+Lapisan enkripsi server tambahan untuk pengiriman ke penerima, untuk mencegah korelasi antara lalu lintas server yang diterima dan dikirim jika TLS disusupi.
+
+### Campuran pesan untuk kurangi korelasi
+
+Server SimpleX bertindak sebagai node campuran latensi rendah — pesan masuk dan keluar memiliki urutan yang berbeda.
+
+### Transport TLS terautentikasi yang aman
+
+Hanya TLS 1.2/1.3 dengan algoritma kuat yang digunakan untuk koneksi client-server.
+
+Sidikjari server dan pengikatan saluran mencegah serangan MITM secara berulang.
+
+Pemulihan koneksi dinonaktifkan untuk mencegah serangan sesi.
+
+### Akses opsional via Tor
+
+Untuk melindungi alamat IP Anda, Anda dapat mengakses server melalui Tor atau lapisan jaringan transport lainnya.
+
+Untuk menggunakan SimpleX melalui Tor, silakan instal [aplikasi Orbot](https://guardianproject.info/apps/org.torproject.android/) dan aktifkan proksi SOCKS5 (atau VPN [di iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Antrean pesan searah
+
+Setiap antrean pesan meneruskan pesan dalam satu arah, dengan alamat kirim dan terima yang berbeda.
+
+Ini mengurangi vektor serangan, dibandingkan dengan perantara pesan tradisional, dan meta-data yang ada.
+
+### Beberapa lapisan kuat konten
+
+SimpleX menggunakan pengunci konten untuk setiap lapisan enkripsi guna menggagalkan serangan pesan.
+
+Ini membuat pesan dengan ukuran berbeda terlihat sama bagi server dan pengamat jaringan.
+
+## Jaringan SimpleX
+
+SimpleX Chat memberikan privasi terbaik dengan menggabungkan keunggulan jaringan P2P dan federasi.
+
+### Tidak seperti jaringan P2P
+
+Semua pesan dikirim melalui server, keduanya memberikan privasi metadata yang lebih baik dan pengiriman pesan asinkron yang andal, sekaligus menghindari banyak .
+
+# Perbandingan dengan protokol perpesanan P2P
+
+Protokol dan aplikasi perpesanan [P2P](https://id.wikipedia.org/wiki/Mitra-ke-mitra) memiliki berbagai masalah yang membuatnya kurang dapat diandalkan dibandingkan SimpleX, lebih rumit untuk dianalisis, dan rentan terhadap beberapa jenis serangan.
+
+1. Jaringan P2P andalkan beberapa varian [DHT](https://id.wikipedia.org/wiki/Tabel_Hash_Terdistribusi) untuk merutekan pesan. Desain DHT harus menyeimbangkan jaminan pengiriman dan latensi. SimpleX memiliki jaminan pengiriman lebih baik dan latensi yang lebih rendah daripada P2P, karena pesan dapat diteruskan secara redundan melalui beberapa server secara paralel, menggunakan server yang dipilih oleh penerima. Dalam jaringan P2P, pesan diteruskan melalui node *O(log N)* secara berurutan, menggunakan node yang dipilih oleh algoritma.
+2. Desain SimpleX, tidak seperti kebanyakan jaringan P2P, tidak memiliki ID pengguna global apa pun, bahkan yang sementara, dan hanya menggunakan pengenal penghubung sementara, sehingga memberikan anonimitas dan perlindungan metadata yang lebih baik.
+3. P2P tidak menyelesaikan masalah [serangan MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack), dan sebagian besar implementasi yang ada tidak menggunakan pesan out-of-band untuk pertukaran kunci awal. SimpleX menggunakan pesan out-of-band atau, dalam beberapa kasus, koneksi aman dan tepercaya yang sudah ada sebelumnya untuk pertukaran kunci awal.
+4. Implementasi P2P dapat diblokir oleh beberapa penyedia internet (seperti [BitTorrent](https://id.wikipedia.org/wiki/BitTorrent)). SimpleX bersifat agnostik transportasi — ia dapat bekerja melalui protokol web standar, misalnya WebSockets.
+5. Semua jaringan P2P yang diketahui mungkin rentan terhadap [serangan Sybil](https://id.wikipedia.org/wiki/Serangan_Sybil), karena setiap node dapat ditemukan, dan jaringan beroperasi secara keseluruhan. Langkah-langkah yang diketahui untuk memitigasinya memerlukan komponen terpusat atau [Bukti kerja](https://id.wikipedia.org/wiki/Bukti_kerja) yang mahal. Jaringan SimpleX tidak memiliki kemampuan untuk ditemukan oleh server, terfragmentasi, dan beroperasi sebagai beberapa sub-jaringan yang terisolasi, sehingga mustahil untuk menyerang seluruh jaringan.
+6. Jaringan P2P mungkin rentan terhadap [serangan DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), ketika klien dapat menyiarkan ulang dan memperkuat lalu lintas, yang mengakibatkan penolakan layanan di seluruh jaringan. Klien SimpleX hanya meneruskan lalu lintas dari koneksi yang diketahui dan tidak dapat digunakan oleh penyerang untuk memperkuat lalu lintas di seluruh jaringan.
+
+---
+
+### Tidak seperti jaringan terfederasi
+
+Server relay SimpleX TIDAK menyimpan profil pengguna, kontak dan pesan yang terkirim, TIDAK terhubung satu sama lain, dan TIDAK ada direktori server.
+
+---
+
+### Jaringan SimpleX
+
+server menyediakan antrean satu arah untuk menghubungkan pengguna, tetapi mereka tidak memiliki visibilitas terhadap grafik koneksi jaringan — hanya pengguna yang memilikinya.
+
+## SimpleX dijelaskan
+
+1. Apa pengalaman pengguna
+
+2. Bagaimana cara kerjanya
+
+3. Apa yang dilihat server
+
+1. Apa pengalaman pengguna
+
+Anda dapat membuat kontak dan grup, dan melakukan percakapan dua arah, seperti pada aplikasi perpesanan lainnya.
+
+Bagaimana cara kerjanya dengan antrean searah dan tanpa pengenal profil pengguna?
+
+2. Bagaimana cara kerjanya
+
+Untuk setiap koneksi, Anda menggunakan dua antrean pesan terpisah untuk mengirim dan menerima pesan melalui server yang berbeda.
+
+Server hanya menyampaikan pesan satu arah, tanpa memiliki gambaran lengkap tentang percakapan atau koneksi pengguna.
+
+3. Apa yang dilihat server
+
+Server memiliki kredensial anonim terpisah untuk setiap antrean, dan tidak mengetahui pengguna mana yang menjadi milik mereka.
+
+Pengguna dapat tingkatkan privasi metadata dengan Tor untuk akses server, mencegah korelasi berdasarkan alamat IP.
+
+## Perbandingan dengan protokol lain
+
+|  |  | Signal, platform besar | XMPP, Matrix | Protokol P2P |
+| --- | --- | --- | --- | --- |
+| Membutuhkan identitas global | Tidak - privat | Ya [1] | Ya [2] | Ya [3] |
+| Kemungkinan MITM | Tidak - aman [4] | Ya [5] | Ya | Ya |
+| Ketergantungan pada DNS | Tidak - tangguh | Ya | Ya | Tidak |
+| Jaringan tunggal atau terpusat | Tidak - terdesentralisasi | Ya | Tidak - terfederasi [6] | Ya [7] |
+| Komponen pusat atau serangan di seluruh jaringan lainnya | Tidak - tangguh | Ya | Ya [2] | Ya [8] |
+
+---
+
+1. Biasanya berdasarkan nomor telepon, dalam beberapa kasus berdasarkan nama pengguna
+2. Alamat berbasis DNS
+3. Kunci publik atau ID unik global lainnya
+4. Relay SimpleX tidak dapat membahayakan enkripsi e2e. Verifikasi kode keamanan untuk memitigasi serangan pada saluran out-of-band
+5. Jika server operator dikompromikan. Verifikasi kode keamanan di Signal dan beberapa aplikasi lain untuk memitigasinya
+6. Tidak melindungi privasi metadata pengguna
+7. Meskipun P2P didistribusikan, mereka tidak terfederasi — mereka beroperasi sebagai jaringan tunggal
+8. Jaringan P2P memiliki otoritas pusat atau seluruh jaringan dapat terkompromi — [lihat disini](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Perbandingan keamanan enkripsi end-to-end di berbagai messenger
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Lapisan pesan | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Penolakan (penyangkalan) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Keamanan post-compromise | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Pertukaran kunci 2 faktor | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Gabungan kriptografi dan post-quantum | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Lapisan pesan ke ukuran yang dibulatkan hingga 1024 byte, Signal - hingga 160 byte
+2. Penolakan tidak mencakup koneksi klien-server.
+3. Tampaknya penggunaan signature kriptografi membahayakan penolakan (penyangkalan), tetapi hal ini perlu diperjelas.
+4. Implementasi multi-perangkat membahayakan keamanan post-compromise Double Ratchet — [lihat disini](https://eprint.iacr.org/2021/626.pdf).
+5. Pertukaran kunci 2 faktor bersifat opsional via verifikasi kode keamanan.
+6. Kesepakatan kunci Post-quantum "jarang" — hanya melindungi beberapa langkah ratchet.
diff --git a/id/messaging/index.html b/id/messaging/index.html
index 9cf84bb127..32e3e45fd0 100644
--- a/id/messaging/index.html
+++ b/id/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda memiliki privasi penuh</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda terlindungi dari<br>spam dan penyalahgunaan</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Data Anda kendali Anda</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda memiliki jaringan SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Fitur ini mengirim pesan tanpa identifikasi profil pengguna, memberikan privasi metadata lebih baik daripada alternatif lainnya.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Untuk mencegahnya, aplikasi SimpleX meneruskan kunci 1-kali di luar jalur, saat bagikan alamat sebagai tautan atau kode QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Kotak kripto NaCL di setiap antrean untuk mencegah korelasi lalu lintas antara antrean pesan jika TLS disusupi.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Jika ada pesan yang ditambah, dihapus atau diubah, penerima akan diberi tahu.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Lapisan enkripsi server tambahan untuk pengiriman ke penerima, untuk mencegah korelasi antara lalu lintas server yang diterima dan dikirim jika TLS disusupi.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Server SimpleX bertindak sebagai node campuran latensi rendah — pesan masuk dan keluar memiliki urutan yang berbeda.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pemulihan koneksi dinonaktifkan untuk mencegah serangan sesi.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Untuk menggunakan SimpleX melalui Tor, silakan instal <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">aplikasi Orbot</a> dan aktifkan proksi SOCKS5 (atau VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">di iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ini mengurangi vektor serangan, dibandingkan dengan perantara pesan tradisional, dan meta-data yang ada.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ini membuat pesan dengan ukuran berbeda terlihat sama bagi server dan pengamat jaringan.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Ketuk untuk tutup</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda memiliki privasi penuh</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda terlindungi dari<br>spam dan penyalahgunaan</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Data Anda kendali Anda</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Anda memiliki jaringan SimpleX</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/id/why.md b/id/why.md
new file mode 100644
index 0000000000..a4665ebf84
--- /dev/null
+++ b/id/why.md
@@ -0,0 +1,19 @@
+# Anda lahir tanpa akun.
+
+Tidak ada yang melacak percakapan Anda. Tidak ada yang membuat peta ke mana Anda pernah pergi. Privasi tidak pernah menjadi fitur — itu adalah cara hidup.
+
+Lalu kita berpindah ke dunia online, dan setiap platform meminta sebagian dari diri Anda — nama, nomor, teman-teman Anda. Kita menerima bahwa harga untuk berbicara dengan orang lain adalah membiarkan seseorang tahu dengan siapa kita berbicara. Dari generasi ke generasi, manusia dan teknologi selalu seperti ini — telepon, email, messenger, media sosial. Tampaknya itu satu-satunya cara yang mungkin.
+
+Ada cara lain. Sebuah jaringan tanpa nomor telepon. Tanpa nama pengguna. Tanpa akun. Tanpa identitas pengguna dalam bentuk apa pun. Sebuah jaringan yang menghubungkan orang dan membawa pesan terenkripsi tanpa mengetahui siapa yang terhubung.
+
+Bukan kunci yang lebih baik di pintu milik orang lain. Bukan pemilik properti yang lebih baik yang menghormati privasi Anda, tetapi tetap menyimpan catatan semua pengunjung. Anda bukan tamu. Anda berada di rumah. Tidak ada raja yang bisa memasukinya — Anda berdaulat.
+
+Percakapan Anda adalah milik Anda, seperti yang selalu terjadi sebelum Internet. Jaringan bukanlah tempat yang Anda kunjungi. Jaringan adalah tempat yang Anda ciptakan dan miliki. Dan tidak seorang pun dapat merampasnya dari Anda, entah Anda menjadikannya privat atau publik.
+
+Kebebasan manusia yang paling tua — berbicara dengan orang lain tanpa diawasi — dibangun di atas infrastruktur yang tidak dapat mengkhianatinya.
+
+Karena kami menghancurkan kekuatan untuk mengetahui siapa Anda. Agar kekuatan *Anda* tidak pernah bisa dirampas.
+
+Bebaslah di jaringan Anda.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/id/why/index.html b/id/why/index.html
index d3615f3a86..8ecc326e41 100644
--- a/id/why/index.html
+++ b/id/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/id/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Bebaslah di jaringan Anda.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/index.html b/index.html
index a679925d1e..ec127205f0 100644
--- a/index.html
+++ b/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/index.md b/index.md
new file mode 100644
index 0000000000..43aea883b3
--- /dev/null
+++ b/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Learn more.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/why)
+
+## Funded by Its Users
+
+To stay independent, large channels and communities will pay for their servers.
+
+And the users can now invest in SimpleX Chat — the equity crowdfunding is live!
+
+[Get a stake in SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/invitation.md b/invitation.md
new file mode 100644
index 0000000000..fd84b8ba88
--- /dev/null
+++ b/invitation.md
@@ -0,0 +1,66 @@
+# You received a 1-time link to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received a 1-time link to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/fdroid)
diff --git a/invitation/index.html b/invitation/index.html
index c3bc77749f..ad0e47427d 100644
--- a/invitation/index.html
+++ b/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received a 1-time link to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/contact.md b/it/contact.md
new file mode 100644
index 0000000000..7753e06a69
--- /dev/null
+++ b/it/contact.md
@@ -0,0 +1,66 @@
+# Hai ricevuto un indirizzo per connetterti su SimpleX Chat
+
+## Scansiona il codice QR con l'app SimpleX Chat sul tuo telefono o tablet.
+
+Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina — sono contenuti nel frammento hash dell'URL del link.
+
+Non hai ancora scaricato SimpleX Chat?
+
+Usa i link sottostanti per scaricare l'app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scansiona il codice QR dall'app mobile
+
+# Hai ricevuto un indirizzo per connetterti su SimpleX Chat
+
+Per stabilire una connessione:
+
+Installa l'app SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid)
+
+1
+
+Connettiti nell'app
+
+Apri l'app SimpleX
+
+2
+
+Tocca il pulsante "connetti" nell'app
+
+3
+
+## Scansiona il codice QR con l'app SimpleX Chat
+
+Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina —
+sono contenuti nel frammento hash dell'URL del link.
+
+## Installazione di SimpleX Chat nel terminale
+
+Usa questo comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Vedi SimpleX Chat Repository GitHub per le istruzioni su come scaricarlo o compilarlo dal codice sorgente.
+
+---
+
+## Se hai già installato SimpleX Chat per il terminale
+
+Se hai già installato SimpleX Chat per il terminale v1.0.0+, copia il comando qui sotto e usalo nella chat:
+
+## Unisciti a SimpleX
+
+Ti invitiamo ad unirti alla conversazione
+
+[Unisciti alla comunità di REDDIT](https://www.reddit.com/r/SimpleXChat/) [Unisciti a noi su GitHub](https://github.com/simplex-chat) [Dona qui per aiutarci](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Iscriviti per ricevere i nostri aggiornamenti
+
+---
+
+Ottieni [l'app desktop](https://simplex.chat/downloads) di SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid)
diff --git a/it/contact/index.html b/it/contact/index.html
index 01c5e2f1a3..de33875a23 100644
--- a/it/contact/index.html
+++ b/it/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Hai ricevuto un indirizzo per connetterti su SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scansiona il codice QR con l'app SimpleX Chat sul tuo telefono o tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina — sono contenuti nel frammento hash dell'URL del link.
+                Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina &mdash; sono contenuti nel frammento hash dell'URL del link.
             </p>
             <p class="text-grey-black dark:text-white text-base">Non hai ancora scaricato SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Usa i link sottostanti per scaricare l'app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installa l'app SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scansiona il codice QR con l'app SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina —<br> sono contenuti nel frammento hash dell'URL del link.
+                            Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina &mdash;<br> sono contenuti nel frammento hash dell'URL del link.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installazione di SimpleX Chat nel terminale</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repository GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Se hai già installato SimpleX Chat per il terminale</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Iscriviti per ricevere i nostri aggiornamenti</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Inserisci il tuo indirizzo email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Ottieni <a href="/downloads">l'app desktop</a> di SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/fdroid.md b/it/fdroid.md
new file mode 100644
index 0000000000..62fd4f7e54
--- /dev/null
+++ b/it/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### Repo di SimpleX Chat
+
+Versioni stabili e beta compilate dagli sviluppatori
+
+Per aggiungerlo al tuo client F-Droid scansiona il codice QR o usa questo URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Impronta della chiave di firma (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Repo di F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Versioni stabili compilate da F-Droid.org
+
+Le pubblicazioni su questo repo avvengono diversi giorni dopo.
+
+I repository di SimpleX Chat e F-Droid.org firmano i pacchetti con chiavi diverse. Per passare da uno all'altro, [esporta](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) il database della chat e reinstalla l'app.
diff --git a/it/fdroid/index.html b/it/fdroid/index.html
index 3a9934052b..3e1702debe 100644
--- a/it/fdroid/index.html
+++ b/it/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Versioni stabili e beta compilate dagli sviluppatori</p>
                         <p>Per aggiungerlo al tuo client F-Droid <span class="hide-on-mobile">scansiona il codice QR o</span> usa questo URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Impronta della chiave di firma (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Repo di F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Versioni stabili compilate da F-Droid.org</p>
                 <p class="mb-2">Le pubblicazioni su questo repo avvengono diversi giorni dopo.</p>
                 <p class="mb-2">I repository di SimpleX Chat e F-Droid.org firmano i pacchetti con chiavi diverse. Per passare da uno all'altro, <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">esporta</a> il database della chat e reinstalla l'app.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/file.md b/it/file.md
new file mode 100644
index 0000000000..f8cb8693c8
--- /dev/null
+++ b/it/file.md
@@ -0,0 +1,31 @@
+# Trasferimento file di SimpleX
+
+Trascina un file qui
+
+o
+
+Scegli file
+
+Max 100 MB - [L'app SimpleX Chat](https://simplex.chat/downloads) supporta file fino a 1 GB
+
+Invia file in modo sicuro con crittografia end-to-end: nessun account, nessun monitoraggio.
+
+## Scarica SimpleX Chat — il messenger più sicuro e privato
+
+Il trasferimento di file appena avviato usa lo stesso protocollo di instradamento dati di SimpleX Chat. L'app offre messaggi crittografati end-to-end, chiamate vocali e video, gruppi e invio di file. Nessun account. Nessun telefono. Nessuna email. Nessun ID utente.
+
+# Protocollo XFTP: il trasferimento di file più sicuro
+
+### Nessun account richiesto
+
+Ogni frammento di file usa una nuova chiave casuale. Gli instradatori di dati non hanno "utenti" o "file": trasferiscono frammenti di file crittografati di dimensioni fisse.
+
+### Crittografia tripla nel tuo browser
+
+La chiave di crittografia dei file è presente solo nel frammento dell'hash dell'URL: il browser non la invia mai a un server. Ci sono 3 strati di crittografia: trasporto TLS, crittografia per-destinatario (chiave effimera unica per trasferimento) e crittografia file end-to-end.
+
+### Instradatori indipendenti di dati
+
+Quando il file è diviso in frammenti, viene inviato tramite instradatori di rete operati da parti indipendenti. Nessun operatore può vedere la vera dimensione o il nome del file. Anche se un instradatore venisse compromesso, potrà vedere solo frammenti cifrati di dimensione fissa. I frammenti di file restano in cache dagli instradatori di rete per circa 48 ore.
+
+[Leggi le specifiche del protocollo XFTP →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/it/file/index.html b/it/file/index.html
index b977d35f15..74720e4360 100644
--- a/it/file/index.html
+++ b/it/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">Trasferimento file di SimpleX</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Trascina un file qui</p>
@@ -693,17 +700,17 @@ window.addEventListener('click',(e)=>{
 <section class="bg-primary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5">
   <div class="container flex flex-col items-center mx-auto text-center">
     <h2 class="text-[35px] leading-[45px] md:text-[45px] md:leading-[55px] text-grey-black dark:text-white font-bold mb-5">
-      Scarica SimpleX Chat — il messenger più sicuro e privato
+      Scarica SimpleX Chat &mdash; il messenger più sicuro e privato
     </h2>
     <p class="text-base text-grey-black dark:text-white mb-14 max-w-[600px]">
       Il trasferimento di file appena avviato usa lo stesso protocollo di instradamento dati di SimpleX Chat. L'app offre messaggi crittografati end-to-end, chiamate vocali e video, gruppi e invio di file. Nessun account. Nessun telefono. Nessuna email. Nessun ID utente.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/it/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/it/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/index.html b/it/index.html
index 712eab3cdf..43e344f04d 100644
--- a/it/index.html
+++ b/it/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/it/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/it/fdroid" title="SimpleX via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Anteprima pubblica per iOS su TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Anteprima pubblica per iOS su TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Analisi della sicurezza" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Ora</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Giu 2027</span>
diff --git a/it/index.md b/it/index.md
new file mode 100644
index 0000000000..630844dc0c
--- /dev/null
+++ b/it/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Vivi libero
+
+## nella tua rete
+
+La prima rete senza ID utente.
+I tuoi contatti, gruppi e canali sono tuoi.
+
+Investi in SimpleX Chat. [Maggiori informazioni.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX via F-Droid](https://simplex.chat/it/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Analisi della sicurezza](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Analisi della
+sicurezza
+
+[Consigli sulla messaggistica di Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [consigli sulla messaggistica di Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Pubblicazioni di Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Recensione di Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Intervista podcast di OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nessuno può vedere con chi parli
+
+Nemmeno i server: tutti i messaggi appaiono come rumore casuale.
+
+Decine di milioni di messaggi recapitati in modo privato ogni giorno.
+
+[Scopri di più sui messaggi di SimpleX](https://simplex.chat/it/messaging)
+
+## La rete è tua
+
+Ogni contatto e gruppo è sul tuo dispositivo, non nel database di un server.
+
+Non c'è una singola entità che controlla la rete: chiunque può gestire i server.
+
+[Perché lo stiamo costruendo](https://simplex.chat/it/why)
+
+## Finanziato dai suoi utenti
+
+Per restare indipendenti, i grandi canali e le comunità pagheranno per i propri server.
+
+E ora gli utenti possono investire in SimpleX Chat — l'equity crowdfunding è attivo!
+
+[Investi in SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Tabella di marcia per un internet libero
+
+2026
+
+: Scalabilità per comunità numerose
+
+Fuga da piattaforme centralizzate
+
+Giu 2027
+
+: Comunità e server sostenibili
+
+Lancio dei Crediti Comunitari
+
+Dic 2027
+
+: Fare crescere le tue comunità
+
+Strumenti per promuovere le tue comunità
+
+[Gruppo utenti SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Unisciti alle comunità di SimpleX
+
+Più di 2 milioni di persone hanno scaricato le app SimpleX.
+
+Trova i tuoi canali e le comunità nella directory e creane di tuoi!
+
+[Vedi la directory di SimpleX](https://simplex.chat/directory)
diff --git a/it/invitation.md b/it/invitation.md
new file mode 100644
index 0000000000..ab13f8b4f5
--- /dev/null
+++ b/it/invitation.md
@@ -0,0 +1,66 @@
+# Hai ricevuto un link una tantum per connetterti su SimpleX Chat
+
+## Scansiona il codice QR con l'app SimpleX Chat sul tuo telefono o tablet.
+
+Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina — sono contenuti nel frammento hash dell'URL del link.
+
+Non hai ancora scaricato SimpleX Chat?
+
+Usa i link sottostanti per scaricare l'app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scansiona il codice QR dall'app mobile
+
+# Hai ricevuto un link una tantum per connetterti su SimpleX Chat
+
+Per stabilire una connessione:
+
+Installa l'app SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid)
+
+1
+
+Connettiti nell'app
+
+Apri l'app SimpleX
+
+2
+
+Tocca il pulsante "connetti" nell'app
+
+3
+
+## Scansiona il codice QR con l'app SimpleX Chat
+
+Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina —
+sono contenuti nel frammento hash dell'URL del link.
+
+## Installazione di SimpleX Chat nel terminale
+
+Usa questo comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Vedi SimpleX Chat Repository GitHub per le istruzioni su come scaricarlo o compilarlo dal codice sorgente.
+
+---
+
+## Se hai già installato SimpleX Chat per il terminale
+
+Se hai già installato SimpleX Chat per il terminale v1.0.0+, copia il comando qui sotto e usalo nella chat:
+
+## Unisciti a SimpleX
+
+Ti invitiamo ad unirti alla conversazione
+
+[Unisciti alla comunità di REDDIT](https://www.reddit.com/r/SimpleXChat/) [Unisciti a noi su GitHub](https://github.com/simplex-chat) [Dona qui per aiutarci](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Iscriviti per ricevere i nostri aggiornamenti
+
+---
+
+Ottieni [l'app desktop](https://simplex.chat/downloads) di SimpleX
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/it/fdroid)
diff --git a/it/invitation/index.html b/it/invitation/index.html
index 6ebeac74cb..ad320d941a 100644
--- a/it/invitation/index.html
+++ b/it/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Hai ricevuto un link una tantum per connetterti su SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scansiona il codice QR con l'app SimpleX Chat sul tuo telefono o tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina — sono contenuti nel frammento hash dell'URL del link.
+                Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina &mdash; sono contenuti nel frammento hash dell'URL del link.
             </p>
             <p class="text-grey-black dark:text-white text-base">Non hai ancora scaricato SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Usa i link sottostanti per scaricare l'app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installa l'app SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scansiona il codice QR con l'app SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina —<br> sono contenuti nel frammento hash dell'URL del link.
+                            Le chiavi pubbliche e l'indirizzo della coda di messaggi in questo link NON vengono inviati in rete quando vedi questa pagina &mdash;<br> sono contenuti nel frammento hash dell'URL del link.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installazione di SimpleX Chat nel terminale</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repository GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Se hai già installato SimpleX Chat per il terminale</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Iscriviti per ricevere i nostri aggiornamenti</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Inserisci il tuo indirizzo email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Ottieni <a href="/downloads">l'app desktop</a> di SimpleX</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/it/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/it/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/messaging.md b/it/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Perché SimpleX è unico
+
+### Hai una privacy completa
+
+SimpleX protegge la privacy del tuo profilo, contatti e metadati, nascondendoli ai server della rete SimpleX e ad eventuali osservatori.
+
+A differenza di qualsiasi altra rete di messaggistica esistente, SimpleX non ha identificatori assegnati agli utenti — **nemmeno numeri casuali**.
+
+### Sei protetto da spam e abusi
+
+Poiché non hai un identificatore o un indirizzo fisso sulla rete SimpleX, nessuno può contattarti a meno che tu non condivida un indirizzo utente una tantum o temporaneo, come codice un QR o un link.
+
+### Sei tu a controllare i tuoi dati
+
+SimpleX conserva tutti i dati utente sui dispositivi client in un **formato trasferibile di database crittografato** — può essere trasferito su un altro dispositivo.
+
+I messaggi crittografati end-to-end vengono conservati temporaneamente sui server di inoltro SimpleX fino alla ricezione, quindi vengono eliminati definitivamente.
+
+### Possiedi la rete SimpleX
+
+La rete SimpleX è completamente decentralizzata e indipendente da qualsiasi criptovaluta o altra rete, ad eccezione di internet.
+
+Puoi **usare SimpleX con i tuoi server personali** o con i server forniti da noi — e connetterti comunque a qualsiasi utente.
+
+# Piena privacy della tua identità, profilo, contatti e metadati
+
+A differenza di altre reti di messaggistica, SimpleX non ha **alcun identificatore assegnato agli utenti**. Non si basa su numeri di telefono, indirizzi basati su domini (come email o XMPP), nomi utente, chiavi pubbliche o persino numeri casuali per identificare i suoi utenti — gli operatori dei server non sanno quante persone usano i loro server.
+
+Per recapitare i messaggi, SimpleX usa [indirizzi anonimi a coppie](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) di code di messaggi unidirezionali, separate per i messaggi ricevuti e inviati, di solito tramite server diversi.
+
+Questo design protegge la privacy di chi stai comunicando, nascondendola ai server della rete SimpleX e a qualsiasi osservatore. Per nascondere il tuo indirizzo IP ai server, puoi **connetterti ai server SimpleX tramite Tor**.
+
+# La migliore protezione da spam e abusi
+
+Poiché non hai alcun identificatore sulla rete SimpleX, nessuno può contattarti a meno che tu non condivida un indirizzo utente una tantum o temporaneo, come un codice QR o un link.
+
+Anche l'indirizzo utente opzionale, che può essere usato per inviare richieste di contatto spam, è possibile modificarlo o eliminarlo completamente senza perdere alcuna connessione.
+
+# Proprietà, controllo e sicurezza dei tuoi dati
+
+SimpleX Chat conserva tutti i dati utente solo sui dispositivi client usando un **formato trasferibile di database crittografato** che può essere esportato e trasferito su qualsiasi dispositivo supportato.
+
+I messaggi crittografati end-to-end vengono conservati temporaneamente sui server di inoltro SimpleX fino alla ricezione, quindi vengono eliminati definitivamente.
+
+A differenza dei server di reti federate (email, XMPP o Matrix), i server SimpleX non conservano gli account utente, ma trasmettono solo i messaggi, proteggendo la privacy di entrambe le parti.
+
+Non ci sono identificatori o testi cifrati in comune tra il traffico del server inviato e quello ricevuto — se qualcuno lo osserva, non può determinare facilmente chi comunica con chi, anche se il TLS è compromesso.
+
+# Completamente decentralizzata — gli utenti possiedono la rete SimpleX
+
+Puoi **usare SimpleX con i tuoi server personali** e continuare a comunicare con le persone che usano i server preconfigurati nelle app.
+
+La rete di SimpleX usa un [protocollo aperto](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) e fornisce un [SDK per creare chat bot](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), consentendo l'implementazione di servizi con cui gli utenti possono interagire tramite le app SimpleX Chat — siamo impazienti di vedere quali servizi SimpleX creerai.
+
+Se stai pensando di sviluppare per la rete SimpleX, ad esempio, il chat bot per gli utenti dell'app SimpleX o l'integrazione della libreria SimpleX Chat nelle tue app mobili, [contattaci](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) per qualsiasi consiglio e supporto.
+
+## Caratteristiche
+
+Messaggi crittografati E2E con markdown e modifica
+
+Immagini, video e file
+crittografati E2E
+
+Gruppi decentralizzati crittografati E2E — solo gli utenti sanno che esistono
+
+Messaggi vocali crittografati E2E
+
+Conversazioni segrete a tempo
+
+Chiamate audio e video
+crittografate E2E
+
+Archiviazione dell'app crittografata e trasferibile — sposta il profilo su un altro dispositivo
+
+Modalità incognito —
+unica su SimpleX Chat
+
+## Cosa rende SimpleX privato
+
+### Identificatori temporanei anonimi a coppie
+
+SimpleX usa indirizzi e credenziali temporanei anonimi a coppie, per ogni contatto o membro del gruppo.
+
+Ciò consente ai messaggi di venire recapitati senza identificatori del profilo utente, garantendo una migliore privacy dei metadati rispetto alle alternative.
+
+### Scambio di chiavi fuori banda
+
+Molte reti di comunicazione sono vulnerabili agli attacchi MITM da parte di server o fornitori di rete.
+
+Per evitarlo, le app SimpleX passano chiavi monouso fuori banda, quando condividi un indirizzo come link o codice QR.
+
+### 2 livelli di crittografia end-to-end
+
+Protocollo Double-ratchet —
+Messaggistica OTR con Perfect Forward Secrecy e recupero da intrusione.
+
+Cryptobox NaCL in ogni coda per evitare correlazioni di traffico tra code di messaggi se il TLS è compromesso.
+
+### Verifica dell'integrità dei messaggi
+
+Per garantire l'integrità, i messaggi sono numerati in sequenza e includono l'hash del messaggio precedente.
+
+Se un messaggio viene aggiunto, rimosso o modificato, il destinatario verrà avvisato.
+
+### Livello aggiuntivo di crittografia lato server
+
+Livello aggiuntivo di crittografia lato server per il recapito al destinatario, per impedire la correlazione tra il traffico del server ricevuto e inviato se il TLS è compromesso.
+
+### Mescolamento dei messaggi per ridurre le correlazioni
+
+I server SimpleX fungono da nodi mix a bassa latenza — i messaggi in entrata e in uscita hanno un ordine diverso.
+
+### Trasporto TLS autenticato sicuro
+
+Usato solo TLS 1.2/1.3 con algoritmi avanzati per connessioni client-server.
+
+Impronta del server e associazione dei canali evitano attacchi MITM e replay.
+
+Ripresa della connessione disattivata per evitare attacchi alla sessione.
+
+### Accesso via Tor opzionale
+
+Per proteggere il tuo indirizzo IP puoi accedere ai server tramite Tor o un'altra rete di trasporto sovrapposta.
+
+Per usare SimpleX tramite Tor, installa [l'app Orbot](https://guardianproject.info/apps/org.torproject.android/) e attiva il proxy SOCKS5 (o VPN [su iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Code di messaggi unidirezionali
+
+Ogni coda di messaggi passa i messaggi in una direzione, con i diversi indirizzi di invio e ricezione.
+
+Riduce i vettori di attacco, rispetto ai broker di messaggi tradizionali, e i metadati disponibili.
+
+### Diversi strati di riempimento dei contenuti
+
+SimpleX usa il riempimento dei contenuti per ogni livello di crittografia per frustrare gli attacchi alle dimensioni dei messaggi.
+
+Fa sì che i messaggi di dimensioni diverse appaiano uguali ai server e a chi osserva la rete.
+
+## Rete di SimpleX
+
+SimpleX Chat offre la migliore privacy combinando i vantaggi del P2P e delle reti federate.
+
+### A differenza delle reti P2P
+
+tutti i messaggi vengono inviati tramite i server, garantendo una migliore privacy dei metadati e una consegna asincrona dei messaggi affidabile, evitando molti .
+
+# Confronto con protocolli di messaggistica P2P
+
+I protocolli e le app di messaggistica [P2P](https://it.wikipedia.org/wiki/Peer-to-peer) hanno diversi problemi che li rendono meno affidabili di SimpleX, più complessi da analizzare e vulnerabili a diversi tipi di attacco.
+
+1. Le reti P2P si basano su alcune varianti di [DHT](https://it.wikipedia.org/wiki/Tabella_di_hash_distribuita) per instradare i messaggi. I progetti DHT devono bilanciare la garanzia di consegna e la latenza. SimpleX ha sia una migliore garanzia di consegna che una latenza minore rispetto al P2P, perché il messaggio può essere passato in modo ridondante attraverso diversi server in parallelo, usando i server scelti dal destinatario. Nelle reti P2P il messaggio viene passato attraverso i nodi *O(log N)* in sequenza, usando nodi scelti dall'algoritmo.
+2. Il design di SimpleX, a differenza della maggior parte delle reti P2P, non ha identificatori utente globali di alcun tipo, nemmeno temporanei, e usa solo identificatori temporanei a coppie, garantendo una maggiore protezione dell'anonimato e dei metadati.
+3. Il P2P non risolve il problema dell'[attacco MITM](https://it.wikipedia.org/wiki/Attacco_man_in_the_middle) e la maggior parte delle implementazioni esistenti non usa messaggi fuori banda per lo scambio iniziale di chiavi. SimpleX usa messaggi fuori banda o, in alcuni casi, connessioni sicure e attendibili preesistenti per lo scambio iniziale di chiavi.
+4. Le implementazioni P2P possono essere bloccate da alcuni fornitori di internet (come [BitTorrent](https://it.wikipedia.org/wiki/BitTorrent)). SimpleX è indipendente dal trasporto — può funzionare su protocolli web standard, es. WebSocket.
+5. Tutte le reti P2P conosciute possono essere vulnerabili all'[attacco di Sybil](https://it.wikipedia.org/wiki/Attacco_di_Sybil), perché ogni nodo è rilevabile e la rete opera come un tutt'uno. Le misure note per mitigarlo richiedono un componente centralizzato o [proof-of-work](https://it.wikipedia.org/wiki/Proof-of-work) costosi. La rete di SimpleX non ha la possibilità di scoprire i server, è frammentata e opera come più sottoreti isolate, rendendo impossibili gli attacchi a livello di rete.
+6. Le reti P2P possono essere vulnerabili all'[attacco DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), quando i client possono ritrasmettere e amplificare il traffico, con conseguente "denial of service" a livello di rete. I client SimpleX si limitano a inoltrare il traffico da connessioni note e non possono essere usati da un aggressore per amplificare il traffico nell'intera rete.
+
+---
+
+### A differenza delle reti federate
+
+i server di inoltro SimpleX NON conservano i profili utente, i contatti e i messaggi consegnati, NON si connettono tra loro e NON esiste una directory dei server.
+
+---
+
+### Nella rete di SimpleX
+
+i server forniscono code unidirezionali per connettere gli utenti, ma non hanno visibilità del grafo delle connessioni di rete — solo gli utenti.
+
+## SimpleX spiegato
+
+1. Cosa fanno gli utenti
+
+2. Come funziona
+
+3. Cosa vedono i server
+
+1. Cosa fanno gli utenti
+
+Puoi creare contatti e gruppi, ed avere conversazioni bidirezionali, come in qualsiasi altro messenger.
+
+Come può funzionare con code unidirezionali e senza identificatori utente?
+
+2. Come funziona
+
+Per ogni connessione usi due code di messaggi distinte per inviare e ricevere i messaggi attraverso server diversi.
+
+I server passano i messaggi solo in una direzione, senza avere il quadro completo delle conversazioni dell'utente o delle connessioni.
+
+3. Cosa vedono i server
+
+I server hanno credenziali anonime separate per ogni coda e non sanno a quali utenti appartengano.
+
+Gli utenti possono aumentare ulteriormente la privacy dei metadati usando Tor per accedere ai server, evitando correlazioni per indirizzo IP.
+
+## Confronto con altri protocolli
+
+|  |  | Signal, grandi piattaforme | XMPP, Matrix | Protocolli P2P |
+| --- | --- | --- | --- | --- |
+| Richiede un'identità globale | No - privato | Sì [1] | Sì [2] | Sì [3] |
+| Possibilità di MITM | No - sicuro [4] | Sì [5] | Sì | Sì |
+| Dipendenza dai DNS | No - resistente | Sì | Sì | No |
+| Rete singola o centralizzata | No - decentralizzato | Sì | No - federato [6] | Sì [7] |
+| Componente centrale o altro attacco a livello di rete | No - resistente | Sì | Sì [2] | Sì [8] |
+
+---
+
+1. Solitamente si basa su un numero di telefono, in alcuni casi su nomi utente
+2. Indirizzi basati su DNS
+3. Chiave pubblica o altro ID univoco globale
+4. I relay di SimpleX non possono compromettere la crittografia e2e. Verifica il codice di sicurezza per mitigare gli attacchi sul canale fuori banda
+5. Se i server dell'operatore sono compromessi. Verifica il codice di sicurezza in Signal e alcune altre app per mitigarlo
+6. Non protegge la privacy dei metadati degli utenti
+7. Sebbene i P2P siano distribuiti, non sono federati — operano come un'unica rete
+8. Le reti P2P hanno un'autorità centrale o l'intera rete può essere compromessa — [vedi qui](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Confronto della sicurezza di crittografia end-to-end in diverse app di messaggistica
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Riempimento dei messaggi | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Ripudio (negabilità) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Sicurezza post-compromissione | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Scambio di chiavi a 2 fattori | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Crittografia ibrida quantistica | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar riempie i messaggi ad una dimensione arrotondata fino a 1024 byte, Signal a 160 byte
+2. Il ripudio non include la connessione client-server.
+3. Sembra che l'uso di firme crittografiche comprometta il ripudio (negabilità), ma occorrono chiarimenti.
+4. L'implementazione multi-dispositivo compromette la sicurezza post-compromissione di Double Ratchet — [vedi qui](https://eprint.iacr.org/2021/626.pdf).
+5. Lo scambio di chiavi a 2 fattori è facoltativo tramite la verifica del codice di sicurezza.
+6. L'accordo sulle chiavi post-quantistico è “scarno” — protegge solo alcuni dei passaggi del ratchet.
diff --git a/it/messaging/index.html b/it/messaging/index.html
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Hai una privacy completa</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sei protetto<br>da spam e abusi</h3>
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Possiedi la rete SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ciò consente ai messaggi di venire recapitati senza identificatori del profilo utente, garantendo una migliore privacy dei metadati rispetto alle alternative.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Per evitarlo, le app SimpleX passano chiavi monouso fuori banda, quando condividi un indirizzo come link o codice QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Cryptobox NaCL in ogni coda per evitare correlazioni di traffico tra code di messaggi se il TLS è compromesso.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Se un messaggio viene aggiunto, rimosso o modificato, il destinatario verrà avvisato.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Livello aggiuntivo di crittografia lato server per il recapito al destinatario, per impedire la correlazione tra il traffico del server ricevuto e inviato se il TLS è compromesso.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">I server SimpleX fungono da nodi mix a bassa latenza — i messaggi in entrata e in uscita hanno un ordine diverso.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ripresa della connessione disattivata per evitare attacchi alla sessione.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Per usare SimpleX tramite Tor, installa <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">l'app Orbot</a> e attiva il proxy SOCKS5 (o VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">su iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Riduce i vettori di attacco, rispetto ai broker di messaggi tradizionali, e i metadati disponibili.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Fa sì che i messaggi di dimensioni diverse appaiano uguali ai server e a chi osserva la rete.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tocca per chiudere</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/old/index.html b/it/old/index.html
index 7fd9b2e67c..f3c668b4ff 100644
--- a/it/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Hai una privacy completa</h3>
                             </div>
 
@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sei protetto<br>da spam e abusi</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sei tu a controllare i tuoi dati</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Possiedi la rete SimpleX</h3>
                             </div>
 
@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/it/why.md b/it/why.md
new file mode 100644
index 0000000000..04d7038d1a
--- /dev/null
+++ b/it/why.md
@@ -0,0 +1,19 @@
+# Sei nato senza un account.
+
+Nessuno monitorava le tue conversazioni. Nessuno disegnava una mappa delle tue posizioni. La privacy non era mai stata una caratteristica, era uno stile di vita.
+
+Poi ci siamo trasferiti online e ogni piattaforma ha chiesto un pezzo di noi: il nome, il numero, gli amici. Abbiamo accettato che il prezzo da pagare per comunicare con gli altri fosse quello di far sapere a qualcuno con chi parliamo. Ogni generazione, sia di persone che di tecnologia, ha funzionato così: telefono, email, messenger, social media. Sembrava l'unico modo possibile.
+
+C'è un'altra via. Una rete senza numeri di telefono. Senza nomi utente. Senza account. Senza identificatori utente di alcun tipo. Una rete che connette le persone e trasferisce messaggi crittografati senza sapere chi è connesso.
+
+Non una serratura migliore sulla porta di qualcun altro. Non un padrone di casa più gentile che rispetta la tua privacy, ma che continua a tenere traccia di tutti i visitatori. Non sei un ospite. Sei a casa tua. Nessun re può entrarvi: sei tu il sovrano.
+
+Le tue conversazioni appartengono a te, come è sempre stato prima dell'avvento di internet. La rete non è un luogo che visiti. È un luogo che crei e possiedi. E nessuno può portartelo via, che tu lo renda privato o pubblico.
+
+La più antica libertà umana, parlare con un'altra persona senza essere osservati, si basa su un'infrastruttura che non può tradirla.
+
+Perché abbiamo distrutto il potere di sapere chi sei. In modo che il *tuo* potere non possa mai esserti sottratto.
+
+Vivi libero nella tua rete.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/it/why/index.html b/it/why/index.html
index 5f4543467c..674a62e016 100644
--- a/it/why/index.html
+++ b/it/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/it/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Vivi libero nella tua rete.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/ja/contact.md b/ja/contact.md
new file mode 100644
index 0000000000..b947ca02af
--- /dev/null
+++ b/ja/contact.md
@@ -0,0 +1,66 @@
+# SimpleX Chatで接続するためのアドレスを受信しました
+
+## スマホ・タブレットのSimpleX ChatアプリでQRコードを読み取ってください。
+
+このページを表示したときに、このリンク内の公開キーとメッセージ キュー アドレスはネットワーク経由で送信されません。 それらはリンク URL のハッシュ フラグメントに含まれています。
+
+SimpleX Chat をまだダウンロードしていませんか?
+
+以下のリンクを使用してアプリをダウンロードしてください。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+モバイルアプリからQRコードをスキャン
+
+# SimpleX Chatで接続するためのアドレスを受信しました
+
+接続するには:
+
+SimpleX アプリをインストールする
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid)
+
+1
+
+アプリで接続する
+
+SimpleXアプリを開く
+
+2
+
+アプリの 「接続」 ボタンをタップしてください
+
+3
+
+## SimpleX Chat アプリで QR コードをスキャン
+
+このリンクの公開キーとメッセージ キュー アドレスは、このページを表示するときにネットワーク経由で送信されません。
+これらはリンク URL のハッシュ フラグメントに含まれています。
+
+## SimpleX チャットをターミナルにインストールする
+
+次のコマンドを使用してください：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+SimpleX チャットを見る GitHub リポジトリ ソースコードからダウンロードまたはコンパイルする方法を説明します。
+
+---
+
+## すでにターミナルに SimpleX Chat をインストールしている場合
+
+すでにインストールしている場合 ターミナル用 SimpleX チャット v1.0.0+, 以下のコマンドをコピーしてチャットで使用します：
+
+## 参加 SimpleX
+
+ぜひ会話にご参加ください
+
+[REDDITコミュニティに参加する](https://www.reddit.com/r/SimpleXChat/) [GitHubで参加する](https://github.com/simplex-chat) [寄付はこちらから](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+最新情報を受け取る
+
+---
+
+SimpleXを入手する [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid)
diff --git a/ja/contact/index.html b/ja/contact/index.html
index 4eb7f24212..6ff405a3d2 100644
--- a/ja/contact/index.html
+++ b/ja/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">SimpleX Chatで接続するためのアドレスを受信しました</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">以下のリンクを使用してアプリをダウンロードしてください。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">SimpleX アプリをインストールする</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">アプリの <span class="text-active-blue">「接続」</span> ボタンをタップしてください</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">アプリの <span class='text-active-blue'>「接続」</span> ボタンをタップしてください</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX Chat アプリで QR コードをスキャン</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX チャットをターミナルにインストールする</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub リポジトリ</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">すでにターミナルに SimpleX Chat をインストールしている場合</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">最新情報を受け取る</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Eメールアドレスを入力してください">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">SimpleXを入手する <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/fdroid.md b/ja/fdroid.md
new file mode 100644
index 0000000000..7fda62643f
--- /dev/null
+++ b/ja/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## F-Droid 経由の SimpleX チャット
+
+### SimpleX チャット リポジトリ
+
+開発者によって構築された安定版とベータ版
+
+F-Droid クライアントに追加するには、QR コードをスキャンするか、次の URL を使用してください：
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+署名キーのフィンガープリント (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org リポジトリ
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+F-Droid.org によって構築された安定バージョン
+
+このリポジトリへのリリースは数日後に行われます.
+
+SimpleX Chat と F-Droid.org リポジトリは、異なるキーを使用してビルドに署名します。 切り替えるには、チャット データベースを[エクスポート](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device)し、アプリを再インストールしてください。
diff --git a/ja/fdroid/index.html b/ja/fdroid/index.html
index f8008f8e5f..06599432ed 100644
--- a/ja/fdroid/index.html
+++ b/ja/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">F-Droid 経由の SimpleX チャット</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">開発者によって構築された安定版とベータ版</p>
-                        <p>F-Droid クライアントに追加するには、<span class="hide-on-mobile">QR コードをスキャンするか</span>、次の URL を使用してください：</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>F-Droid クライアントに追加するには、<span class='hide-on-mobile'>QR コードをスキャンするか</span>、次の URL を使用してください：</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             署名キーのフィンガープリント (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org リポジトリ</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">F-Droid.org によって構築された安定バージョン</p>
                 <p class="mb-2">このリポジトリへのリリースは数日後に行われます.</p>
                 <p class="mb-2">SimpleX Chat と F-Droid.org リポジトリは、異なるキーを使用してビルドに署名します。 切り替えるには、チャット データベースを<a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">エクスポート</a>し、アプリを再インストールしてください。</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/file.md b/ja/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/ja/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/ja/file/index.html b/ja/file/index.html
index decd081bde..dc4ca180ad 100644
--- a/ja/file/index.html
+++ b/ja/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/index.html b/ja/index.html
index 7b756d8953..7c4adf30c9 100644
--- a/ja/index.html
+++ b/ja/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/ja/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/ja/fdroid" title="F-Droid経由のSimpleXアプリ"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="セキュリティ監査" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">現在</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">2027年6月</span>
diff --git a/ja/index.md b/ja/index.md
new file mode 100644
index 0000000000..ebb41b373b
--- /dev/null
+++ b/ja/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# 自由で あれ
+
+## あなたのネットワークで
+
+ユーザーIDのない世界初のネットワーク。
+連絡先、グループ、チャンネルはあなたのものです。
+
+Invest in SimpleX Chat. [さらに詳しく.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [F-Droid経由のSimpleXアプリ](https://simplex.chat/ja/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[セキュリティ監査](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+セキュリティ
+監査
+
+[Privacy Guide 推奨](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix推奨](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online の記事](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Mike Kuketzによるレビュー](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut ポッドキャストインタビュー](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## 誰と話しているか、誰にも見えません
+
+サーバーですら見ることはできません – すべてのメッセージはランダムなノイズに見えます。
+
+毎日数千万件のメッセージがプライベートに配信されています。
+
+[SimpleXのメッセージ機能について詳しく知る](https://simplex.chat/ja/messaging)
+
+## ネットワークは あなたのもの
+
+すべての連絡先とグループはあなたのデバイス上にあり、サーバーのデータベースにはありません。
+
+ネットワークを支配する単一の組織はありません – 誰でもサーバーを運用できます。
+
+[Why we are building it](https://simplex.chat/ja/why)
+
+## ユーザーの資金で運営
+
+独立性を維持するため、大規模なチャンネルやコミュニティはサーバー費用を負担します。
+
+ユーザーはSimpleX Chatに投資できるようになりました — クラウドファンディングが始まりました！
+
+[SimpleX Chatに投資する](https://simplex.chat/crowdfunding/)
+
+## 自由なインターネットを目指す SimpleX ロードマップ
+
+2026
+
+: 大規模コミュニティへの拡張
+
+中央集権型プラットフォームからの脱却
+
+2027年6月
+
+: サステナブルなコミュニティ&サーバ
+
+コミュニティクレジットの開始
+
+2027年12月
+
+: コミュニティの成長
+
+コミュニティを広げるツール
+
+[SimpleXユーザグループ](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## SimpleXコミュニティに参加する
+
+200万人以上がSimpleXアプリをダウンロードしました。
+
+ディレクトリでチャンネルやコミュニティを見つけて、あなた自身のものを作成しましょう！
+
+[SimpleXディレクトリを見る](https://simplex.chat/directory)
diff --git a/ja/invitation.md b/ja/invitation.md
new file mode 100644
index 0000000000..410cc7ba01
--- /dev/null
+++ b/ja/invitation.md
@@ -0,0 +1,66 @@
+# SimpleX Chatで接続するための使い捨てのリンクを受信しました
+
+## スマホ・タブレットのSimpleX ChatアプリでQRコードを読み取ってください。
+
+このページを表示したときに、このリンク内の公開キーとメッセージ キュー アドレスはネットワーク経由で送信されません。 それらはリンク URL のハッシュ フラグメントに含まれています。
+
+SimpleX Chat をまだダウンロードしていませんか?
+
+以下のリンクを使用してアプリをダウンロードしてください。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+モバイルアプリからQRコードをスキャン
+
+# SimpleX Chatで接続するための使い捨てのリンクを受信しました
+
+接続するには:
+
+SimpleX アプリをインストールする
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid)
+
+1
+
+アプリで接続する
+
+SimpleXアプリを開く
+
+2
+
+アプリの 「接続」 ボタンをタップしてください
+
+3
+
+## SimpleX Chat アプリで QR コードをスキャン
+
+このリンクの公開キーとメッセージ キュー アドレスは、このページを表示するときにネットワーク経由で送信されません。
+これらはリンク URL のハッシュ フラグメントに含まれています。
+
+## SimpleX チャットをターミナルにインストールする
+
+次のコマンドを使用してください：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+SimpleX チャットを見る GitHub リポジトリ ソースコードからダウンロードまたはコンパイルする方法を説明します。
+
+---
+
+## すでにターミナルに SimpleX Chat をインストールしている場合
+
+すでにインストールしている場合 ターミナル用 SimpleX チャット v1.0.0+, 以下のコマンドをコピーしてチャットで使用します：
+
+## 参加 SimpleX
+
+ぜひ会話にご参加ください
+
+[REDDITコミュニティに参加する](https://www.reddit.com/r/SimpleXChat/) [GitHubで参加する](https://github.com/simplex-chat) [寄付はこちらから](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+最新情報を受け取る
+
+---
+
+SimpleXを入手する [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ja/fdroid)
diff --git a/ja/invitation/index.html b/ja/invitation/index.html
index 97319b41a0..a63577be6c 100644
--- a/ja/invitation/index.html
+++ b/ja/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">SimpleX Chatで接続するための使い捨てのリンクを受信しました</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">以下のリンクを使用してアプリをダウンロードしてください。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">SimpleX アプリをインストールする</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">アプリの <span class="text-active-blue">「接続」</span> ボタンをタップしてください</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">アプリの <span class='text-active-blue'>「接続」</span> ボタンをタップしてください</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX Chat アプリで QR コードをスキャン</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX チャットをターミナルにインストールする</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub リポジトリ</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">すでにターミナルに SimpleX Chat をインストールしている場合</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">最新情報を受け取る</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Eメールアドレスを入力してください">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">SimpleXを入手する <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/messaging.md b/ja/messaging.md
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--- /dev/null
+++ b/ja/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## なぜSimpleXが唯一無二なのか
+
+### プライバシーが完全に守られます
+
+SimpleXは、SimpleXネットワークのサーバやその他の観察者から隠すことで、あなたのプロフィール、連絡先やメタデータのプライバシーを守ります。
+
+その他の既存のメッセージネットワークと異なり、SimpleXはユーザへ識別子を割り当てません — **ランダムな番号さえありません**。
+
+### スパムや悪用から 保護されています
+
+あなたは識別子や固定されたアドレスをSimpleXネットワーク上で持たないため、あなたがQRコードやリンクといった一度のみ使用可能もしくは一時的なユーザアドレスを共有しない限り、誰もあなたへ連絡することができません。
+
+### データを管理するのはあなたです
+
+SimpleXはクライアント端末上の全てのユーザデータを **ポータブルで暗号化されたデータベースフォーマット**で保管します—別の端末へ移行することができます。
+
+エンドツーエンドで暗号化されたメッセージは、SimpleXのリレーサーバ上で受信されるまで一時的に保管され、その後永久的に削除されます。
+
+### SimpleX ネットワークを所有
+
+SimpleXネットワークは、インターネット以外のいかなる暗号通貨やネットワークから独立しており、完全に分散化されています。
+
+あなたは私たちの提供するサーバや **自分自身のサーバでSimpleXを使う** ことができます — そして別のユーザとつながることができます。
+
+# ID、プロフィール、連絡先、メタデータの完全なプライバシー
+
+他のメッセージングネットワークとは異なり、SimpleX には**ユーザーに割り当てられる識別子がありません**。 ユーザーを識別するために、電話番号、ドメインベースのアドレス (電子メールや XMPP など)、ユーザー名、公開キー、さらには乱数にも依存しません。 — サーバオペレータはどれだけの人が利用しているかも知ることはありません。
+
+メッセージを配信するために、SimpleX は一方向メッセージ キューの[ペアワイズ匿名アドレス](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier)を使用し、受信メッセージと送信メッセージに分けて、通常は異なるサーバーを経由します。
+
+この設計により、通信相手のプライバシーが保護され、SimpleX ネットワークサーバや監視者からプライバシーが隠されます。 IP アドレスをサーバから隠すには、**Tor 経由で SimpleX サーバーに接続**します。
+
+# スパムと悪用からの最高の保護
+
+SimpleXネットワークには識別子がないため、ワンタイムまたは一時的なユーザー アドレスを QR コードまたはリンクとして共有しない限り、誰もあなたに連絡することはできません。
+
+オプションのユーザー アドレスを使用しても、スパムの連絡先リクエストの送信に使用される可能性がありますが、接続を失うことなく変更または完全に削除できます。
+
+# データの所有権、管理、セキュリティ
+
+SimpleX Chat は、サポートされているデバイスにエクスポートして転送できる**ポータブル暗号化データベース形式**を使用して、すべてのユーザー データをクライアント デバイスにのみ保存します。
+
+エンドツーエンドで暗号化されたメッセージは、SimpleXのリレーサーバーで受信するまで一時的に保持され、その後永久に削除されます。
+
+電子メール、XMPP、Matrixなどの連携ネットワークサーバーとは異なり、SimpleXサーバーはユーザーアカウントを保存せず、メッセージの中継のみを行い、双方のプライバシーを保護します。
+
+送受信されるサーバー トラフィックの間に共通の識別子や暗号文はありません。 — 誰かがそれを観察している場合、たとえ TLS が侵害されたとしても、誰が誰と通信しているのかを簡単に判断することはできません。
+
+# 完全に分散化されています — ユーザーは SimpleX ネットワークを所有します
+
+あなたが、**自分自身のサーバでSimpleXを使っても**、アプリで予め設定されたサーバを使う方々と連絡を取ることができます。
+
+SimpleXネットワークは、SimpleX Chatアプリを介してユーザが交流するサービスを実装させつつ[オープンプロトコル](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md)を使い、[チャットボットを作成するためにSDK](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript)を提供します—私たちはあなた達がどのようなSimpleXのサービスを築くか本当に楽しみです。
+
+例えば、SimpleXアプリユーザへのチャットボットやSimpleX Chatライブラリーの携帯アプリへの統合など、SimpleXネットワークに関する開発を検討してくださっているようでしたら、どのようなアドバイスや支援のことでも[ご連絡ください](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) 。
+
+## 特徴
+
+マークダウンと編集を使用可能なE2E 暗号化メッセージ
+
+E2E暗号化された
+画像とファイル
+
+分散型シークレットグループ —
+ユーザーのみがその存在を知っています
+
+E2E暗号化された音声メッセージ
+
+消えるメッセージ
+
+E2E暗号化された
+音声通話とビデオ通話
+
+ポータブルな暗号化データベース — プロファイルを別のデバイスに移動する
+
+シークレット モード —
+SimpleX Chat に固有の
+
+## SimpleX をプライベートにするもの
+
+### 一時的な匿名のペア識別子
+
+SimpleX は、ユーザー連絡先またはグループ メンバーごとに、一時的な匿名のペアごとのアドレスと資格情報を使用します。
+
+ユーザー プロファイル識別子なしでメッセージが配信されるため、他の方法よりも優れたメタデータ プライバシーが提供されます。
+
+### 帯域外の 鍵交換
+
+多くの通信ネットワークは、サーバーやネットワーク プロバイダーによるMITM 攻撃に対して脆弱です。
+
+これを防ぐために、SimpleX アプリは、アドレスをリンクまたは QR コードとして共有するときに、ワンタイム キーを帯域外で渡します。
+
+### 2レイヤーの エンドツーエンド暗号化
+
+ダブルラチェットプロトコル —
+完全な前方秘匿性と侵入回復機能を備えたOTRメッセージング。
+
+各キューのNaCL cryptoboxは、TLSが侵害された場合にメッセージキュー間のトラフィック相関を防止します。
+
+### メッセージの整合性 検証
+
+整合性を保証するために、メッセージには連続した番号が付けられ、前のメッセージのハッシュが含まれます。
+
+メッセージが追加、削除、または変更されると、受信者に警告が表示されます。
+
+### 追加レイヤーの サーバー暗号化
+
+TLSが侵害された場合、受信したサーバー・トラフィックと送信したサーバー・トラフィックの相関を防ぐため、受信者に配信するサーバー暗号化レイヤーを追加します。
+
+### メッセージのミキシング 相関性を減らす
+
+SimpleX サーバーは、低遅延の混合ノードとして機能します — 受信メッセージと送信メッセージの順序が異なります。
+
+### セキュアな認証付き TLSトランスポート
+
+クライアント/サーバー接続には、強力なアルゴリズムを備えた TLS 1.2/1.3 のみが使用されます。
+
+サーバーのフィンガープリントとチャネル バインディングにより、MITM 攻撃やリプレイ攻撃を防止します。
+
+セッション攻撃を防ぐために、接続の再開は無効になっています。
+
+### オプション Tor経由のアクセス
+
+IP アドレスを保護するために、Tor またはその他のトランスポート オーバーレイ ネットワーク経由でサーバーにアクセスできます。
+
+Tor経由でSimpleXを使用するには、[Orbotアプリ](https://guardianproject.info/apps/org.torproject.android/)をインストールし、SOCKS5プロキシを有効にしてください（iOSの場合は[VPN](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)）。
+
+### 単方向 メッセージキュー
+
+各メッセージ キューは、異なる送信アドレスと受信アドレスを使用してメッセージを一方向に渡します。
+
+従来のメッセージ ブローカーと比較して、攻撃ベクトルが減少し、利用可能なメタデータが減少します。
+
+### 何レイヤーもの コンテンツパディング
+
+SimpleX は、各暗号化レイヤーにコンテンツ パディングを使用して、メッセージ サイズ攻撃を阻止します。
+
+これにより、異なるサイズのメッセージがサーバーやネットワーク オブザーバーには同じように見えます。
+
+## SimpleX ネットワーク
+
+SimpleX Chat は、P2P とフェデレーション ネットワークの利点を組み合わせて最高のプライバシーを提供します。
+
+### P2Pネットワークとは異なります
+
+すべてのメッセージはサーバー経由で送信され、メタデータのプライバシーが向上し、信頼性の高い非同期メッセージ配信が提供されると同時に、多くが回避されます .
+
+# P2Pメッセージングプロトコルとの比較
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) メッセージング プロトコルとアプリには、SimpleX よりも信頼性が低く、分析がより複雑になるさまざまな問題があり、また、いくつかの種類の攻撃に対して脆弱です。
+
+1. P2P ネットワークは、メッセージをルーティングするために [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) の一部の変種に依存します。 DHT の設計では、配信保証と遅延のバランスを取る必要があります。 SimpleX は、受信者が選択したサーバーを使用して、メッセージを複数のサーバーを介して並行して冗長的に渡すことができるため、P2P よりも優れた配信保証と低い遅延の両方を備えています。 P2P ネットワークでは、メッセージはアルゴリズムによって選択されたノードを使用して、*O(log N)* 個のノードを順番に通過します。
+2. SimpleX 設計は、ほとんどの P2P ネットワークとは異なり、一時的であってもいかなる種類のグローバル ユーザー識別子も持たず、一時的なペアごとの識別子のみを使用するため、より優れた匿名性とメタデータ保護が提供されます。
+3. P2P は [MITM 攻撃](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) 問題を解決せず、既存の実装のほとんどは最初の鍵交換に帯域外メッセージを使用していません 。 SimpleX は、最初のキー交換に帯域外メッセージを使用するか、場合によっては既存の安全で信頼できる接続を使用します。
+4. P2P の実装は、一部のインターネット プロバイダー ([BitTorrent](https://en.wikipedia.org/wiki/BitTorrent) など) によってブロックされる場合があります。 SimpleX はトランスポートに依存しません — WebSocketのような標準的な Web プロトコル上で動作します。
+5. すべての既知の P2P ネットワークは、各ノードが検出可能であり、ネットワーク全体が動作するため、[Sybil 攻撃](https://en.wikipedia.org/wiki/Sybil_attack)に対して脆弱である可能性があります。 この問題を軽減する既知の対策には、一元化されたコンポーネントか、高価な[作業証明](https://en.wikipedia.org/wiki/Proof_of_work)が必要です。 SimpleX ネットワークにはサーバーの検出機能がなく、断片化されており、複数の分離されたサブネットワークとして動作するため、ネットワーク全体への攻撃は不可能です。
+6. P2P ネットワークは、[DRDoS 攻撃](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent)に対して脆弱になる可能性があります。 クライアントがトラフィックを再ブロードキャストして増幅する可能性があり、その結果、ネットワーク全体のサービス拒否が発生する可能性があります。 SimpleX クライアントは既知の接続からのトラフィックのみを中継するため、攻撃者がネットワーク全体のトラフィックを増幅するために使用することはできません。
+
+---
+
+### 連合型ネットワークとは異なります
+
+SimpleX リレー サーバーは、ユーザー プロファイル、連絡先、配信されたメッセージを保存せず、相互に接続せず、サーバー ディレクトリもありません。
+
+---
+
+### SimpleX ネットワーク
+
+サーバーはユーザーを接続するための一方向キューを提供しますが、ネットワーク接続グラフは表示されません— ユーザーだけがそうします。
+
+## SimpleXの説明
+
+1. ユーザーが経験すること
+
+2. 仕組み
+
+3. サーバーが認識するもの
+
+1. ユーザーが経験すること
+
+他のメッセンジャーと同様に、連絡先やグループを作成し、双方向の会話を行うことができます。
+
+ユーザー プロファイル識別子なしで単方向キューをどのように処理できるのでしょうか?
+
+2. 仕組み
+
+接続ごとに 2 つの個別のメッセージング キューを使用して、異なるサーバー経由でメッセージを送受信します。
+
+サーバーは、ユーザーの会話や接続の全体を把握することなく、メッセージを一方向に送信するだけです。
+
+3. サーバーが認識するもの
+
+サーバーはキューごとに個別の匿名認証情報を持っており、どのユーザーに属しているかはわかりません。
+
+ユーザーは、Tor を使用してサーバーにアクセスし、IP アドレスによる相関を防ぐことで、メタデータのプライバシーをさらに向上させることができます。
+
+## 他のプロトコルとの比較
+
+|  |  | Signal、大きなプラットフォーム | XMPP、Matrix | P2Pプロトコル |
+| --- | --- | --- | --- | --- |
+| グローバル ID が必要 | いいえ - プライベート | はい [1] | はい [2] | はい [3] |
+| MITMの可能性 | いいえ - 安全 [4] | はい [5] | はい | はい |
+| DNS への依存 | いいえ - 弾力性 | はい | はい | いいえ |
+| 単一または集中型ネットワーク | いいえ - 分散型 | はい | いいえ - 連合型 [6] | はい [7] |
+| 中央コンポーネントまたはその他のネットワーク全体の攻撃 | いいえ - 弾力性 | はい | はい [2] | はい [8] |
+
+---
+
+1. 通常は電話番号に基づいていますが、場合によってはユーザー名に基づいています
+2. DNSベースのアドレス
+3. 公開キーまたはその他のグローバルに一意な ID
+4. SimpleX リレーは e2e 暗号化を侵害できません。 セキュリティ コードを検証して帯域外チャネルへの攻撃を軽減します
+5. オペレーターのサーバーが侵害された場合。 Signal およびその他の一部のアプリでセキュリティ コードを検証して緩和する
+6. ユーザーのメタデータのプライバシーを保護しない
+7. P2Pは分散されていますが、フェデレーションされていません — 単一のネットワークとして動作します
+8. P2Pネットワークには中央当局が存在するか、ネットワーク全体が侵害される可能性がある — [こちらを見る](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| 前方秘匿性 | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2ファクタ鍵交換 | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| ポスト量子ハイブリッド暗号 | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. 否認可能性の対象には、クライアントとサーバー間の接続は含まれません。
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [こちらを見る](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/ja/messaging/index.html b/ja/messaging/index.html
index 964d55e47b..f8d8e61f72 100644
--- a/ja/messaging/index.html
+++ b/ja/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">プライバシーが完全に守られます</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">スパムや悪用から<br>保護されています</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">データを管理するのはあなたです</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX ネットワークを所有</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">ユーザー プロファイル識別子なしでメッセージが配信されるため、他の方法よりも優れたメタデータ プライバシーが提供されます。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">これを防ぐために、SimpleX アプリは、アドレスをリンクまたは QR コードとして共有するときに、ワンタイム キーを帯域外で渡します。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">各キューのNaCL cryptoboxは、TLSが侵害された場合にメッセージキュー間のトラフィック相関を防止します。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">メッセージが追加、削除、または変更されると、受信者に警告が表示されます。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">TLSが侵害された場合、受信したサーバー・トラフィックと送信したサーバー・トラフィックの相関を防ぐため、受信者に配信するサーバー暗号化レイヤーを追加します。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX サーバーは、低遅延の混合ノードとして機能します — 受信メッセージと送信メッセージの順序が異なります。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">セッション攻撃を防ぐために、接続の再開は無効になっています。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Tor経由でSimpleXを使用するには、<a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbotアプリ</a>をインストールし、SOCKS5プロキシを有効にしてください（iOSの場合は<a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">VPN</a>）。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
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                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">従来のメッセージ ブローカーと比較して、攻撃ベクトルが減少し、利用可能なメタデータが減少します。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
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                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">これにより、異なるサイズのメッセージがサーバーやネットワーク オブザーバーには同じように見えます。</p>
                             
                         </div>
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@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/old/index.html b/ja/old/index.html
index dd6b23e05d..0562003c65 100644
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+++ b/ja/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">プライバシーの基準を新境地に</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -749,13 +754,13 @@ window.addEventListener('click',(e)=>{
     多くのユーザーは、<em>SimpleX にユーザー識別子がない場合、メッセージの配信先をどのようにして知ることができるのでしょうか?</em> と質問しました
 </p>
 <p>
-    メッセージを配信するために、SimpleX は、他のすべてのネットワークで使用されるユーザー ID の代わりに、接続ごとに個別のメッセージ キューの一時的な匿名ペア識別子を使用します — 長期的な識別子はありません。
+    メッセージを配信するために、SimpleX は、他のすべてのネットワークで使用されるユーザー ID の代わりに、接続ごとに個別のメッセージ キューの一時的な匿名ペア識別子を使用します &mdash; 長期的な識別子はありません。
 </p>
 <p>
-    メッセージの受信に使用するサーバー、連絡先を定義します —メッセージを送信するために使用するサーバー。 すべての会話では 2 つの異なるサーバーが使用される可能性があります。
+    メッセージの受信に使用するサーバー、連絡先を定義します &mdash;メッセージを送信するために使用するサーバー。 すべての会話では 2 つの異なるサーバーが使用される可能性があります。
 </p>
 <p>
-    この設計により、ユーザーの情報の漏洩が防止されます' アプリケーションレベルのメタデータ。 プライバシーをさらに向上させ、IP アドレスを保護するために、Tor 経由でメッセージング サーバーに接続できます。
+    この設計により、ユーザーの情報の漏洩が防止されます&apos; アプリケーションレベルのメタデータ。 プライバシーをさらに向上させ、IP アドレスを保護するために、Tor 経由でメッセージング サーバーに接続できます。
 </p>
 <p>
     クライアント デバイスのみがユーザー プロファイル、連絡先、およびグループを保存します。 メッセージは 2 レイヤーのエンドツーエンド暗号化を使用して送信されます。
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">SimpleXを入手する <a href="/downloads">desktop app</a></p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -931,8 +936,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">なぜプライバシーが<span class="gradient-text">重要</span>なのか</h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">メタデータのプライバシーを保護する — <span class="text-active-blue">話す相手</span> — 以下のことからあなたを守ります：</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">なぜプライバシーが<span class='gradient-text'>重要</span>なのか</h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">メタデータのプライバシーを保護する &mdash; <span class='text-active-blue'>話す相手</span> &mdash; 以下のことからあなたを守ります：</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     オンライン小売業者は、収入が低い人ほど急ぎの買い物をする可能性が高いことを知っているため、より高い価格を請求したり、割引を廃止したりすることがあります。
 </p>
 <p>
-    一部の金融会社や保険会社は、ソーシャル グラフを使用して金利や保険料を決定しています。 多くの場合、収入の低い人にはより多くの料金を支払わなければなりません。 —これは、<a href="https://fairbydesign.com/povertypremium/" target="_blank">"「貧困プレミアム」"</a> として知られています。
+    一部の金融会社や保険会社は、ソーシャル グラフを使用して金利や保険料を決定しています。 多くの場合、収入の低い人にはより多くの料金を支払わなければなりません。 &mdash;これは、<a href="https://fairbydesign.com/povertypremium/" target="_blank">"「貧困プレミアム」"</a> として知られています。
 </p>
 <p>
     SimpleXネットワークは、他のどのプラットフォームよりも接続のプライバシーを保護し、ソーシャル グラフが企業や組織に利用されることを完全に防ぎます。 SimpleX Chatアプリに予め設定されたサーバを利用している場合でも、サーバオペレータはユーザーの数や接続数を知ることはできません。
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1001,7 +1006,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    つい最近まで、主要な選挙が <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">有名なコンサルティング会社</a>によって操作されていました。 ソーシャルグラフは私たちの現実世界の見方を歪め、投票を操作しています。
+    つい最近まで、主要な選挙が <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>有名なコンサルティング会社</a>によって操作されていました。 ソーシャルグラフは私たちの現実世界の見方を歪め、投票を操作しています。
 </p>
 <p>
     客観的であり、独立した意思決定を行うには、情報空間を制御する必要があります。 これは、ソーシャル グラフにアクセスできないプライベートコミュニケーションネットワークを使用している場合にのみ可能です。
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1048,13 +1053,13 @@ window.addEventListener('click',(e)=>{
     誰もが通信のプライバシーとセキュリティに気を配る必要があります。 たとえ何も隠すものがなかったとしても、無害な会話はあなたを危険にさらす可能性があります。
 </p>
 <p>
-    最も衝撃的な話の 1 つは、<a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">Mohamedou Ould Salahi</a>の経験であり、彼の回顧録に記述され、『モーリタニア映画』で紹介されています。彼はアフガニスタンの親戚に電話をかけた後、アメリカ同時多発テロへの関与の疑いで拘束されました。 彼は裁判も受けずにグアンタナモ収容所に入れられ、そこで15年間拷問を受けました。
+    最も衝撃的な話の 1 つは、<a href='https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi' target='_blank'>Mohamedou Ould Salahi</a>の経験であり、彼の回顧録に記述され、『モーリタニア映画』で紹介されています。彼はアフガニスタンの親戚に電話をかけた後、アメリカ同時多発テロへの関与の疑いで拘束されました。 彼は裁判も受けずにグアンタナモ収容所に入れられ、そこで15年間拷問を受けました。
 </p>
 <p>
-    一般の人が、たとえ「匿名」アカウント経由であっても、オンラインで共有した内容で逮捕されます。<a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout -catholic-mother-malicious-online-posts.html" target="_blank">それは、たとえ民主主義の国であったとしても同じです</a>。
+    一般の人が、たとえ「匿名」アカウント経由であっても、オンラインで共有した内容で逮捕されます。<a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout -catholic-mother-malicious-online-posts.html' target='_blank'>それは、たとえ民主主義の国であったとしても同じです</a>。
 </p>
 <p>
-    エンドツーエンドで暗号化されたメッセンジャーを使用するだけでは十分ではありません。私たちは皆、個人ネットワークのプライバシーを保護するメッセンジャーを使用する必要があります — 私たちがつながっているのは誰なのか。
+    エンドツーエンドで暗号化されたメッセンジャーを使用するだけでは十分ではありません。私たちは皆、個人ネットワークのプライバシーを保護するメッセンジャーを使用する必要があります &mdash; 私たちがつながっているのは誰なのか。
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1083,7 +1088,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">なぜSimpleXが<span class="gradient-text">唯一無二</span>なのか</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">なぜSimpleXが<span class='gradient-text'>唯一無二</span>なのか</h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">プライバシーが完全に守られます</h3>
                             </div>
 
@@ -1109,7 +1114,7 @@ window.addEventListener('click',(e)=>{
     SimpleXは、SimpleXネットワークのサーバやその他の観察者から隠すことで、あなたのプロフィール、連絡先やメタデータのプライバシーを守ります。
 </p>
 <p>
-    その他の既存のメッセージネットワークと異なり、SimpleXはユーザへ識別子を割り当てません — <strong>ランダムな番号さえありません</strong>。
+    その他の既存のメッセージネットワークと異なり、SimpleXはユーザへ識別子を割り当てません &mdash; <strong>ランダムな番号さえありません</strong>。
 </p>
 
                                     </div>
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">詳細情報</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">情報を隠す</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">スパムや悪用から<br>保護されています</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">詳細情報</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">情報を隠す</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">データを管理するのはあなたです</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleXはクライアント端末上の全てのユーザデータを <strong>ポータブルで暗号化されたデータベースフォーマット</strong>で保管します—別の端末へ移行することができます。
+    SimpleXはクライアント端末上の全てのユーザデータを <strong>ポータブルで暗号化されたデータベースフォーマット</strong>で保管します&mdash;別の端末へ移行することができます。
 </p>
 <p>
     エンドツーエンドで暗号化されたメッセージは、SimpleXのリレーサーバ上で受信されるまで一時的に保管され、その後永久的に削除されます。
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">詳細情報</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">情報を隠す</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX ネットワークを所有</h3>
                             </div>
 
@@ -1259,7 +1264,7 @@ window.addEventListener('click',(e)=>{
     SimpleXネットワークは、インターネット以外のいかなる暗号通貨やネットワークから独立しており、完全に分散化されています。
 </p>
 <p>
-    あなたは私たちの提供するサーバや <strong>自分自身のサーバでSimpleXを使う</strong> ことができます — そして別のユーザとつながることができます。
+    あなたは私たちの提供するサーバや <strong>自分自身のサーバでSimpleXを使う</strong> ことができます &mdash; そして別のユーザとつながることができます。
 </p>
 
                                     </div>
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">詳細情報</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">情報を隠す</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1320,10 +1325,10 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    他のメッセージングネットワークとは異なり、SimpleX には<strong>ユーザーに割り当てられる識別子がありません</strong>。 ユーザーを識別するために、電話番号、ドメインベースのアドレス (電子メールや XMPP など)、ユーザー名、公開キー、さらには乱数にも依存しません。 — サーバオペレータはどれだけの人が利用しているかも知ることはありません。
+    他のメッセージングネットワークとは異なり、SimpleX には<strong>ユーザーに割り当てられる識別子がありません</strong>。 ユーザーを識別するために、電話番号、ドメインベースのアドレス (電子メールや XMPP など)、ユーザー名、公開キー、さらには乱数にも依存しません。 &mdash; サーバオペレータはどれだけの人が利用しているかも知ることはありません。
 </p>
 <p>
-    メッセージを配信するために、SimpleX は一方向メッセージ キューの<a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">ペアワイズ匿名アドレス</a>を使用し、受信メッセージと送信メッセージに分けて、通常は異なるサーバーを経由します。
+    メッセージを配信するために、SimpleX は一方向メッセージ キューの<a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>ペアワイズ匿名アドレス</a>を使用し、受信メッセージと送信メッセージに分けて、通常は異なるサーバーを経由します。
 </p>
 <p>
     この設計により、通信相手のプライバシーが保護され、SimpleX ネットワークサーバや監視者からプライバシーが隠されます。 IP アドレスをサーバから隠すには、<strong>Tor 経由で SimpleX サーバーに接続</strong>します。
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     電子メール、XMPP、Matrixなどの連携ネットワークサーバーとは異なり、SimpleXサーバーはユーザーアカウントを保存せず、メッセージの中継のみを行い、双方のプライバシーを保護します。
 </p>
 <p>
-    送受信されるサーバー トラフィックの間に共通の識別子や暗号文はありません。 — 誰かがそれを観察している場合、たとえ TLS が侵害されたとしても、誰が誰と通信しているのかを簡単に判断することはできません。
+    送受信されるサーバー トラフィックの間に共通の識別子や暗号文はありません。 &mdash; 誰かがそれを観察している場合、たとえ TLS が侵害されたとしても、誰が誰と通信しているのかを簡単に判断することはできません。
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">完全に分散化されています — ユーザーは SimpleX ネットワークを所有します</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">完全に分散化されています &mdash; ユーザーは SimpleX ネットワークを所有します</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     あなたが、<strong>自分自身のサーバでSimpleXを使っても</strong>、アプリで予め設定されたサーバを使う方々と連絡を取ることができます。
 </p>
 <p>
-    SimpleXネットワークは、SimpleX Chatアプリを介してユーザが交流するサービスを実装させつつ<a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">オープンプロトコル</a>を使い、<a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">チャットボットを作成するためにSDK</a>を提供します—私たちはあなた達がどのようなSimpleXのサービスを築くか本当に楽しみです。
+    SimpleXネットワークは、SimpleX Chatアプリを介してユーザが交流するサービスを実装させつつ<a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>オープンプロトコル</a>を使い、<a href='https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript' target='_blank'>チャットボットを作成するためにSDK</a>を提供します&mdash;私たちはあなた達がどのようなSimpleXのサービスを築くか本当に楽しみです。
 </p>
 <p>
-    例えば、SimpleXアプリユーザへのチャットボットやSimpleX Chatライブラリーの携帯アプリへの統合など、SimpleXネットワークに関する開発を検討してくださっているようでしたら、どのようなアドバイスや支援のことでも<a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">ご連絡ください</a> 。
+    例えば、SimpleXアプリユーザへのチャットボットやSimpleX Chatライブラリーの携帯アプリへの統合など、SimpleXネットワークに関する開発を検討してくださっているようでしたら、どのようなアドバイスや支援のことでも<a href='https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>ご連絡ください</a> 。
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">マークダウンと編集を使用可能なE2E 暗号化メッセージ</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">E2E暗号化された<br>画像とファイル</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">分散型シークレットグループ —<br>ユーザーのみがその存在を知っています</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">分散型シークレットグループ &mdash;<br>ユーザーのみがその存在を知っています</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">E2E暗号化された音声メッセージ</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">消えるメッセージ</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">E2E暗号化された<br>音声通話とビデオ通話</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">ポータブルな暗号化データベース — プロファイルを別のデバイスに移動する</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">ポータブルな暗号化データベース &mdash; プロファイルを別のデバイスに移動する</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">シークレット モード — <br>SimpleX Chat に固有の</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">シークレット モード &mdash; <br>SimpleX Chat に固有の</p>
             </div>
             
         </div>
@@ -1570,7 +1575,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">SimpleX を<span class="gradient-text">プライベート</span>にするもの</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">SimpleX を<span class='gradient-text'>プライベート</span>にするもの</h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">一時的な匿名のペア識別子</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">帯域外の<br>鍵交換</h3>
@@ -1614,14 +1619,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">2レイヤーの<br>エンドツーエンド暗号化</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">ダブルラチェットプロトコル —<br>完全な前方秘匿性と侵入回復機能を備えたOTRメッセージング。</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">ダブルラチェットプロトコル &mdash;<br>完全な前方秘匿性と侵入回復機能を備えたOTRメッセージング。</p>
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">各キューのNaCL cryptoboxは、TLSが侵害された場合にメッセージキュー間のトラフィック相関を防止します。</p>
                             
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">メッセージの整合性<br>検証</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">追加レイヤーの<br>サーバー暗号化</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">メッセージのミキシング<br>相関性を減らす</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX サーバーは、低遅延の混合ノードとして機能します — 受信メッセージと送信メッセージの順序が異なります。</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX サーバーは、低遅延の混合ノードとして機能します &mdash; 受信メッセージと送信メッセージの順序が異なります。</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">タップして閉じる</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">セキュアな認証付き<br>TLSトランスポート</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">オプション<br>Tor経由のアクセス</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">単方向<br>メッセージキュー</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">何レイヤーもの<br>コンテンツパディング</h3>
@@ -1774,14 +1779,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class="gradient-text">ネットワーク</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class='gradient-text'>ネットワーク</span></h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">SimpleX Chat は、P2P とフェデレーション ネットワークの利点を組み合わせて最高のプライバシーを提供します。</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">P2Pネットワークとは異なります</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         すべてのメッセージはサーバー経由で送信され、メタデータのプライバシーが向上し、信頼性の高い非同期メッセージ配信が提供されると同時に、多くが回避されます <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">P2Pネットワークの問題点</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">P2Pメッセージングプロトコルとの比較</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1797,7 +1802,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    <a href="https://en.wikipedia.org/wiki/Peer-to-peer">P2P</a> メッセージング プロトコルとアプリには、SimpleX よりも信頼性が低く、分析がより複雑になるさまざまな問題があり、また、いくつかの種類の攻撃に対して脆弱です。
+    <a href='https://en.wikipedia.org/wiki/Peer-to-peer'>P2P</a> メッセージング プロトコルとアプリには、SimpleX よりも信頼性が低く、分析がより複雑になるさまざまな問題があり、また、いくつかの種類の攻撃に対して脆弱です。
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
@@ -1810,7 +1815,7 @@ window.addEventListener('click',(e)=>{
         P2P は <a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">MITM 攻撃</a> 問題を解決せず、既存の実装のほとんどは最初の鍵交換に帯域外メッセージを使用していません 。 SimpleX は、最初のキー交換に帯域外メッセージを使用するか、場合によっては既存の安全で信頼できる接続を使用します。
     </li>
     <li>
-        P2P の実装は、一部のインターネット プロバイダー (<a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a> など) によってブロックされる場合があります。 SimpleX はトランスポートに依存しません — WebSocketのような標準的な Web プロトコル上で動作します。
+        P2P の実装は、一部のインターネット プロバイダー (<a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a> など) によってブロックされる場合があります。 SimpleX はトランスポートに依存しません &mdash; WebSocketのような標準的な Web プロトコル上で動作します。
     </li>
     <li>
         すべての既知の P2P ネットワークは、各ノードが検出可能であり、ネットワーク全体が動作するため、<a href="https://en.wikipedia.org/wiki/Sybil_attack">Sybil 攻撃</a>に対して脆弱である可能性があります。 この問題を軽減する既知の対策には、一元化されたコンポーネントか、高価な<a href="https://en.wikipedia.org/wiki/Proof_of_work">作業証明</a>が必要です。 SimpleX ネットワークにはサーバーの検出機能がなく、断片化されており、複数の分離されたサブネットワークとして動作するため、ネットワーク全体への攻撃は不可能です。
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">連合型ネットワークとは異なります</h3>
@@ -1862,13 +1867,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">SimpleX ネットワーク</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        サーバーはユーザーを接続するための<span class="text-active-blue">一方向キュー</span>を提供しますが、ネットワーク接続グラフは表示されません— ユーザーだけがそうします。
+                        サーバーはユーザーを接続するための<span class="text-active-blue">一方向キュー</span>を提供しますが、ネットワーク接続グラフは表示されません&mdash; ユーザーだけがそうします。
                     </p>
                 </div>
             </div>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. ユーザーが経験すること</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             他のメッセンジャーと同様に、連絡先やグループを作成し、双方向の会話を行うことができます。
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. 仕組み</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             接続ごとに 2 つの個別のメッセージング キューを使用して、異なるサーバー経由でメッセージを送受信します。
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. サーバーが認識するもの</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             サーバーはキューごとに個別の匿名認証情報を持っており、どのユーザーに属しているかはわかりません。
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal、大きなプラットフォーム</th>
                         <th class="pb-4">XMPP、Matrix</th>
@@ -2111,7 +2116,7 @@ window.addEventListener("load", function () {
                     <li> SimpleX リレーは e2e 暗号化を侵害できません。 セキュリティ コードを検証して帯域外チャネルへの攻撃を軽減します</li>
                     <li> オペレーターのサーバーが侵害された場合。 Signal およびその他の一部のアプリでセキュリティ コードを検証して緩和する</li>
                     <li> ユーザーのメタデータのプライバシーを保護しない</li>
-                    <li> P2Pは分散されていますが、フェデレーションされていません — 単一のネットワークとして動作します</li>
+                    <li> P2Pは分散されていますが、フェデレーションされていません &mdash; 単一のネットワークとして動作します</li>
                     <li> P2Pネットワークには中央当局が存在するか、ネットワーク全体が侵害される可能性がある - <a class="underline text-primary-light dark:text-primary-dark underline-offset-2" href="https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols">こちらを見る</a></li>
                 </ol>
             </div>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">最新情報を受け取る</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Eメールアドレスを入力してください">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">SimpleXを入手する <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ja/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ja/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ja/why.md b/ja/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/ja/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/ja/why/index.html b/ja/why/index.html
index ac46a8f34b..426951271b 100644
--- a/ja/why/index.html
+++ b/ja/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ja/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/jobs.md b/jobs.md
new file mode 100644
index 0000000000..65a66b7f99
--- /dev/null
+++ b/jobs.md
@@ -0,0 +1,48 @@
+# Join SimpleX Chat team
+
+Join SimpleX Chat team to build the future of secure, private, and decentralized communications.
+
+## Who we are looking for
+
+### iOS Engineer
+
+We are looking for an entrepreneurial iOS engineer.
+
+Please send your exceptional achievements related to iOS (created in your own free time, or via grants, or startups you co-founded, but not as part of employment or contract):
+- popular iOS open-source libraries or frameworks.
+- iOS apps you developed on your own or as part of 2-people team.
+- technical publications about iOS engineering.
+
+This is a full-time remote contract. You must be in UTC +/- 8 hours timezone.
+
+### Application Engineer
+
+We are looking for an entrepreneurial Android/Desktop applications engineer with an advanced expertise in:
+- Kotlin Multiplatform.
+- Jetpack Compose and JVM development.
+- desktop applications for Linux, Mac and Windows.
+- advanced knowledge of C/C++, Java, JavaScript and some other programming languages.
+
+Please send your exceptional engineering achievements (created in your own free time, or via grants, or startups you co-founded, but not as part of employment or contract):
+- popular open-source libraries, frameworks or applications.
+- apps you developed on your own or as part of 2-3 people team.
+- technical publications about engineering.
+
+This is a full-time remote contract. You must be in UTC +/- 8 hours timezone.
+
+<h3>Community Builder</h3>
+
+We are looking for an entrepreneurial Community Builder and Marketer, with successful crowdfunding experience.
+
+Please send your exceptional achievements related to community building, social media marketing, or crowdfunding (created in your free time or in startups you co-founded, but not as part of contract or employment):
+- large, active online communities, social media accounts, podcasts, or YouTube channels.
+- successful crowdfunding campaigns that raised significant funds.
+- high-profile publications, interviews, or viral content pieces.
+
+This is a part-time remote contract. You must be in UTC +/- 8 hours timezone.
+
+## How to join the team
+
+To apply, please [install SimpleX Chat app](https://simplex.chat/downloads/index.html) and send your achievements to this [SimpleX address](https://smp16.simplex.im/a#OGL3qf7utOrUERFoFOROgdQaAkj_znzoeACNKDAsFNA).
+
+**We do NOT review CVs at the initial stage, please only send the links to your achievements**.
diff --git a/jobs/index.html b/jobs/index.html
index f00f174067..0856eed00a 100644
--- a/jobs/index.html
+++ b/jobs/index.html
@@ -52,6 +52,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8" />
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+        
+<link rel="alternate" type="text/markdown" href="/jobs.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
         <link href="/css/tailwind.css" rel="stylesheet" />
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css" />
diff --git a/links.md b/links.md
new file mode 100644
index 0000000000..7234ed4a60
--- /dev/null
+++ b/links.md
@@ -0,0 +1,2685 @@
+# Community Links
+
+## SimpleX Chat Wants Its 400K+ Users to Become Investors Too [#](https://simplex.chat/links/#link=simplex-chat-wants-its-400k-users-to-become-investors-too)
+
+It's FOSS
+
+Aug 14, 2026 English Article
+
+[https://itsfoss.com/news/simplex-chat-investment-drive/](https://itsfoss.com/news/simplex-chat-investment-drive/)
+
+## SimpleX Chat: Private Monero Communities — and Now a Chance to Invest [#](https://simplex.chat/links/#link=simplex-chat-private-monero-communities-and-now-a-chance-to-invest)
+
+Monerica
+
+Aug 10, 2026 English Article
+
+SimpleX Chat calls itself “the messaging network that can’t identify you,” and that is not marketing hyperbole — it is the actual design. For a privacy community built around Monero, that combination of unlinkable messaging and unlinkable money is a natural fit. This post looks at why SimpleX matters, the growing set of private Monero communities already running on it, and the news that users can now buy a stake in the project itself through an equity crowdfunding round on Wefunder.
+
+[https://blog.monerica.com/articles/simplex-chat-private-monero-communities](https://blog.monerica.com/articles/simplex-chat-private-monero-communities)
+
+## Web3 Summit Talk: "SimpleX Community Credits: Making Privacy Profitable" [#](https://simplex.chat/links/#link=web3-summit-talk-simplex-community-credits-making-privacy-profitable)
+
+SimpleX Chat
+
+Jul 2026 English Conference talk
+
+Alain Brenzikofer presents our design for Community Credits at Web3 Summit – a payment solution for private infrastructure payments on SimpleX network. See the whitepaper at: https://simplex.chat/credits/whitepaper.pdf
+
+[https://www.youtube.com/watch?v=UhW8AuoRgxg](https://www.youtube.com/watch?v=UhW8AuoRgxg)
+
+## Best Secure Messaging Apps: Signal vs Session vs SimpleX vs Briar [#](https://simplex.chat/links/#link=best-secure-messaging-apps-signal-vs-session-vs-simplex-vs-briar)
+
+State of Surveillance
+
+May 2026 English Comparison
+
+This secure messaging comparison guide evaluates Signal, Session, SimpleX, Briar, WhatsApp, and Telegram across criteria including phone number requirements, architecture, and metadata protection. SimpleX is highlighted as requiring no phone number, using a decentralized architecture with no metadata collection, and being best suited for maximum privacy, though the guide notes its small user base as a practical limitation.
+
+[https://stateofsurveillance.org/guides/basic/secure-messaging-comparison/](https://stateofsurveillance.org/guides/basic/secure-messaging-comparison/)
+
+## SimpleX Chat: Product Showcase - Removing User Identifiers From Messaging [#](https://simplex.chat/links/#link=simplex-chat-product-showcase-removing-user-identifiers-from-messaging)
+
+Help Net Security
+
+Apr 29, 2026 English Review
+
+Help Net Security showcases SimpleX Chat as a free, private, open-source messenger that eliminates traditional user identifiers and stores data locally on devices. The article highlights end-to-end encrypted communications, contact addition through one-time links or QR codes, encrypted audio/video calls via WebRTC with hidden IP addresses, and security verification through comparable security codes between contacts.
+
+[https://www.helpnetsecurity.com/2026/04/29/product-showcase-simplex-chat-secure-messaging/](https://www.helpnetsecurity.com/2026/04/29/product-showcase-simplex-chat-secure-messaging/)
+
+## The Only TRULY Anonymous Chat: SimpleX [#](https://simplex.chat/links/#link=the-only-truly-anonymous-chat-simplex)
+
+L'unica chat VERAMENTE anonima | SimpleX
+
+rdwei
+
+Apr 2026 Italian Review
+
+[https://www.youtube.com/watch?v=Eamu0Ys63l4](https://www.youtube.com/watch?v=Eamu0Ys63l4)
+
+## Comparison of Instant Messengers [#](https://simplex.chat/links/#link=comparison-of-instant-messengers)
+
+Eylenburg
+
+Apr 2026 (updated) English Comparison
+
+This comprehensive messenger comparison states that SimpleX "probably has the best privacy and anonymity of all the messengers compared here," noting it requires no accounts or IDs and users connect via one-time invitation links. It identifies the main limitation as adoption - being a relatively new app with few users makes it impractical for most people who need to communicate with existing contacts.
+
+[https://eylenburg.github.io/im_comparison.htm](https://eylenburg.github.io/im_comparison.htm)
+
+## Evgeny Poberezkin on SimpleX Private Chat [#](https://simplex.chat/links/#link=evgeny-poberezkin-on-simplex-private-chat)
+
+Citadel Dispatch
+
+Mar 20, 2026 English Podcast
+
+This Citadel Dispatch podcast episode features Evgeny Poberezkin discussing SimpleX Chat's radically different approach to user identity, where addresses are assigned to connections rather than endpoints. The conversation covers critiques of the MLS protocol, upcoming scalable channels to rival Telegram, and a sustainability model where large channels fund network operations.
+
+[https://podcasts.apple.com/is/podcast/cd196-evgeny-poberezkin-simplex-private-chat/id1546393840?i=1000756411661](https://podcasts.apple.com/is/podcast/cd196-evgeny-poberezkin-simplex-private-chat/id1546393840?i=1000756411661)
+
+## SimpleX Chat Video Review [#](https://simplex.chat/links/#link=simplex-chat-video-review)
+
+PeerTube Uno Italia
+
+Mar 8, 2026 Italian Review
+
+Video review of SimpleX Chat v5.4 on Italian federated PeerTube instance. Covers connecting mobile and desktop apps via quantum-resistant protocol and improved group features.
+
+[https://peertube.uno/w/ecD1N1HjNC4SBvmWusnTC2](https://peertube.uno/w/ecD1N1HjNC4SBvmWusnTC2)
+
+## Which Messengers Work in Russia and Which Are Blocked [#](https://simplex.chat/links/#link=which-messengers-work-in-russia-and-which-are-blocked)
+
+Kakie messendzhery rabotayut v Rossii a kakie zablokirovany
+
+AppVisor.ru
+
+Mar 6, 2026 Russian Article
+
+This Russian article reports that SimpleX Chat was among several decentralized messengers blocked by Moscow City Court order in September 2024, alongside Briar, Session, and Verum. It notes the blocking was due to SimpleX's architecture that makes user tracking technically extremely difficult.
+
+[https://appvisor.ru/post/news/kakie-messendzhery-rabotayut-v-rossii-a-kakie-zablokirovany/](https://appvisor.ru/post/news/kakie-messendzhery-rabotayut-v-rossii-a-kakie-zablokirovany/)
+
+## SimpleX Chat [#](https://simplex.chat/links/#link=simplex-chat-italian)
+
+Freeonline.org
+
+Feb 17, 2026 (updated) Italian Review
+
+This Italian review awards SimpleX Chat "Site of the Day" status, describing it as a messaging platform that eliminates user identifiers entirely. It highlights advanced end-to-end encryption, local-only data storage, Tor network access, and availability across all major platforms, while noting the experience is more technical than competing services.
+
+[https://www.freeonline.org/simplex-chat/](https://www.freeonline.org/simplex-chat/)
+
+## Communicate Online in Complete Anonymity [#](https://simplex.chat/links/#link=communicate-online-in-complete-anonymity)
+
+SimpleX Chat: comunicare online in totale anonimato
+
+Web Apps Magazine
+
+Feb 15, 2026 Italian Article
+
+This Italian article presents SimpleX as a paradigm shift in private messaging, highlighting its lack of phone number requirements, decentralized relay system, and metadata protection. It positions the app for journalists, activists, and privacy-conscious users, while honestly noting the tradeoff of losing all contacts if the phone is lost without backups.
+
+[https://webappsmagazine.blogspot.com/2026/02/simplex-chat-comunicare-online-in.html](https://webappsmagazine.blogspot.com/2026/02/simplex-chat-comunicare-online-in.html)
+
+## MoneroTopia 2026: The Future of SimpleX Network [#](https://simplex.chat/links/#link=monerotopia-2026-the-future-of-simplex-network)
+
+SimpleX Chat
+
+Feb 15, 2026 English Conference talk
+
+SimpleX Chat presentation at MoneroTopia 2026 conference in Mexico City, covering the latest developments in the SimpleX network and its alignment with the Monero privacy ecosystem.
+
+[https://www.youtube.com/live/Alp-hVCoF7c?si=FqOTt1mCeQJVo-cM&t=16688](https://www.youtube.com/live/Alp-hVCoF7c?si=FqOTt1mCeQJVo-cM&t=16688)
+
+## SimpleX Chat: Privacy Without Compromise [#](https://simplex.chat/links/#link=simplex-chat-privacy-without-compromise)
+
+SimpleX Chat - prywatnosc bez kompromisow
+
+opentech.guru
+
+Feb 2026 Polish Review
+
+This Polish article describes SimpleX as a fully open-source, decentralized messenger that eliminates user identifiers entirely, using separate one-way message queues per contact. It highlights double ratchet and post-quantum key exchange encryption, incognito mode, Tor connectivity, and availability across all major platforms including CLI, calling the servers "dumb pipes" with no knowledge of who connects with whom.
+
+[https://opentech.guru/simplex-chat-prywatnosc-bez-kompromisow/](https://opentech.guru/simplex-chat-prywatnosc-bez-kompromisow/)
+
+## The Messaging App With No User IDs [#](https://simplex.chat/links/#link=the-messaging-app-with-no-user-ids)
+
+SimpleX Interview
+
+Techlore
+
+Jan 24, 2026 English Podcast
+
+[https://www.youtube.com/watch?v=hfzf0t8ZCK4](https://www.youtube.com/watch?v=hfzf0t8ZCK4)
+
+## Which Encrypted Messenger Is Best Secured? Signal, Session and SimpleX [#](https://simplex.chat/links/#link=which-encrypted-messenger-is-best-secured-signal-session-and-simplex)
+
+Quelle messagerie chiffree est la mieux securisee? Signal, Session et SimpleX mais pas Whatsapp!
+
+Nicolas Forcet
+
+Jan 2, 2026 French Comparison
+
+This French-language article positions SimpleX between Signal and Session in a security hierarchy, noting its protocol design prevents servers from mapping social connections by using separate channels for incoming and outgoing messages. SimpleX is praised for stronger privacy protections including app-level locking, ephemeral messages, and Tor/VPN compatibility, though the author notes lower adoption rates may be a practical drawback.
+
+[https://nicolasforcet.com/messagerie-chiffree-2026-signal-simplex-session/](https://nicolasforcet.com/messagerie-chiffree-2026-signal-simplex-session/)
+
+## SimpleX Chat Review 2026: Open-Source Secure Messaging [#](https://simplex.chat/links/#link=simplex-chat-review-2026-open-source-secure-messaging)
+
+Darwin Dynamic
+
+2026 English Review
+
+This 2026 review describes SimpleX Chat as a strong privacy option that eliminates unique user IDs and features end-to-end encryption with decentralized routing. The reviewer notes a learning curve and ongoing development issues as drawbacks, but ultimately recommends it for privacy-conscious individuals willing to navigate a more complex interface than mainstream alternatives.
+
+[https://darwindynamic.com/simplex-chat-review-2026/](https://darwindynamic.com/simplex-chat-review-2026/)
+
+## The 5 Best Private Chat and Message Apps for 2026 [#](https://simplex.chat/links/#link=the-5-best-private-chat-and-message-apps-for-2026)
+
+Darwin Dynamic
+
+2026 English Comparison
+
+SimpleX Chat ranks third among five recommended private messaging apps for 2026. The article emphasizes that it requires no user identification, making it highly secure and anonymous, while noting that initial configuration can be challenging and occasional technical issues may occur.
+
+[https://darwindynamic.com/5-best-private-chat-message-apps-for-2026/](https://darwindynamic.com/5-best-private-chat-message-apps-for-2026/)
+
+## Best Decentralized Private Messengers in 2026 [#](https://simplex.chat/links/#link=best-decentralized-private-messengers-in-2026)
+
+Factually
+
+2026 English Comparison
+
+This product comparison ranks SimpleX as the best choice for maximal anonymity and minimal metadata, describing its peer-to-peer design that avoids server-mediated trust and emphasizes anonymity. The review notes SimpleX's UI is minimal and focused on anonymity features, but acknowledges the app is younger, less battle-tested, and has a smaller user base compared to Signal and Matrix.
+
+[https://factually.co/product-reviews/electronics-tech/best-decentralized-private-messengers-2026-signal-session-simplex-matrix-a6216a](https://factually.co/product-reviews/electronics-tech/best-decentralized-private-messengers-2026-signal-session-simplex-matrix-a6216a)
+
+## 8 Best Secure Messaging Apps for Encrypted Chats in 2026 [#](https://simplex.chat/links/#link=8-best-secure-messaging-apps-for-encrypted-chats-in-2026)
+
+CloudSEK
+
+2026 English Comparison
+
+CloudSEK positions SimpleX as the best phone-number-free messaging app, highlighting its relay-based routing, zero metadata approach, and private invitation links instead of identity-based profiles. The article notes a trade-off between SimpleX's strong metadata protection and its smaller user community compared to more established platforms like Signal or Telegram.
+
+[https://www.cloudsek.com/knowledge-base/best-secure-messaging-apps](https://www.cloudsek.com/knowledge-base/best-secure-messaging-apps)
+
+## 10 Best Secure Messaging Apps You Should Check Out in 2026 [#](https://simplex.chat/links/#link=10-best-secure-messaging-apps-you-should-check-out-in-2026)
+
+Beebom
+
+2026 English Comparison
+
+Beebom lists SimpleX Chat third among the best secure messaging apps, calling it the "Best Minimal Secure Messaging App." The article highlights its lack of user IDs, incognito mode with random usernames, live message typing preview, screenshot blocking, and contact verification, noting it requires no email or phone number to use.
+
+[https://beebom.com/best-secure-messaging-apps/](https://beebom.com/best-secure-messaging-apps/)
+
+## Decentralized Messengers: 8 WhatsApp and Telegram Alternatives 2026 [#](https://simplex.chat/links/#link=decentralized-messengers-8-whatsapp-and-telegram-alternatives-2026)
+
+Децентрализованные мессенджеры: 8 альтернатив WhatsApp и Telegram в 2026 году
+
+itforprof.com
+
+2026 Russian Comparison
+
+This Russian-language article describes SimpleX Chat as a decentralized platform that uses cryptographic keys instead of accounts for identification and employs Double Ratchet encryption with quantum-resistant extensions. The article notes that servers cannot access metadata about who communicates with whom, but warns that SimpleX is blocked by Roskomnadzor in Russia and requires a VPN to access.
+
+[https://itforprof.com/blog/decentralizovannye-messendzhery/](https://itforprof.com/blog/decentralizovannye-messendzhery/)
+
+## Release of SimpleX Chat 6.5 [#](https://simplex.chat/links/#link=release-of-simplex-chat-65)
+
+Выпуск SimpleX Chat 6.5, ориентированный на консорциум и краудфандинг для независимости
+
+OpenNet.ru
+
+2026 Russian News
+
+This Russian tech news site covers the SimpleX Chat 6.5 release, highlighting the introduction of channels with stateful messaging capabilities and the establishment of the SimpleX Network Consortium for network independence and governance. The update also brings improved web access features and SOCKS proxy support.
+
+[https://opennet.ru/65337/](https://opennet.ru/65337/)
+
+## 14 Best Secure Messengers of 2026 [#](https://simplex.chat/links/#link=14-best-secure-messengers-of-2026)
+
+14 лучших безопасных мессенджеров 2026
+
+pro32.com
+
+2026 Russian Comparison
+
+This Russian article listing 14 secure messengers highlights SimpleX's unique architecture without user identifiers, where contacts are added via QR codes or invitation links. It identifies SimpleX as one of the most promising options for bypassing blockades, suitable for users prioritizing anonymity and censorship resistance.
+
+[https://pro32.com/ru/article/14-samykh-bezopasnykh-messendzherov-kakoy-vybrat-dlya-lichnoy-i-rabochey-perepiski/](https://pro32.com/ru/article/14-samykh-bezopasnykh-messendzherov-kakoy-vybrat-dlya-lichnoy-i-rabochey-perepiski/)
+
+## Safe and Private Messaging Apps Similar to Signal [#](https://simplex.chat/links/#link=safe-and-private-messaging-apps-similar-to-signal)
+
+Factually
+
+2026 English Comparison
+
+This product review compares secure messaging apps similar to Signal, noting that Session and SimpleX prioritize privacy-first engineering over mainstream polish. SimpleX is highlighted for avoiding phone-number registration and using no persistent user IDs, offering stronger anonymity than Signal at the cost of convenience and sometimes reliability, while Session uses onion routing which can cause delays and missed notifications.
+
+[https://factually.co/product-reviews/electronics-tech/safe-private-messaging-apps-similar-to-signal-84872a](https://factually.co/product-reviews/electronics-tech/safe-private-messaging-apps-similar-to-signal-84872a)
+
+## Looking Back at 2025: Top 10 Influential Figures in the Crypto Industry [#](https://simplex.chat/links/#link=looking-back-at-2025-top-10-influential-figures-in-the-crypto-industry)
+
+Hui wang 2025: ying xiang jia mi hang ye de shi da nian du feng yun ren wu
+
+Tencent News
+
+Dec 22, 2025 Chinese News
+
+This Chinese article reviewing the top 10 influential figures in the crypto industry for 2025 mentions SimpleX briefly in the context of Vitalik Buterin donating 128 ETH each to Session and SimpleX Chat. It quotes Vitalik emphasizing that digital privacy protection through encrypted messaging is crucial, citing permissionless account creation and metadata privacy as key development directions.
+
+[https://news.qq.com/rain/a/20251222A01LTC00](https://news.qq.com/rain/a/20251222A01LTC00)
+
+## Telegram Alternative Apps: Stronger Anonymous Messenger Recommendations [#](https://simplex.chat/links/#link=telegram-alternative-apps-stronger-anonymous-messenger-recommendations)
+
+텔레그램 대체 앱: 더 강력한 익명 메신저 추천
+
+NetXHack
+
+Dec 17, 2025 (updated) Korean Guide
+
+This Korean-language comparison of Telegram alternatives describes SimpleX as an identifier-free distributed framework that requires no phone numbers or account IDs. The article notes SimpleX's relay servers remain ignorant of senders and receivers, but acknowledges it prioritizes anonymity over user experience and is better suited for small groups needing secure communication.
+
+[https://netxhack.com/apps/foss/alternatives-to-telegram/](https://netxhack.com/apps/foss/alternatives-to-telegram/)
+
+## From Privacy to Social: Web3 Needs an All-in-One Encrypted Social Application [#](https://simplex.chat/links/#link=from-privacy-to-social-web3-needs-an-all-in-one-encrypted-social-application)
+
+Cong yin si dao she jiao: Web3 xu yao yi zhan shi jia mi she jiao ying yong
+
+Golden Finance / KasTop
+
+Dec 17, 2025 Chinese News
+
+This Chinese article about Web3 encrypted social applications positions SimpleX as an important advancement in decentralized private communication, noting Vitalik's 128 ETH donation. While praising SimpleX's end-to-end encryption and lack of user identifiers, the article argues that comprehensive platforms combining privacy with full Web3 social features represent the next evolutionary stage beyond SimpleX.
+
+[https://www.kastop.com/Item/1995.aspx](https://www.kastop.com/Item/1995.aspx)
+
+## BlockTop: From Privacy to Social - Web3 and Encrypted Social Applications [#](https://simplex.chat/links/#link=blocktop-from-privacy-to-social-web3-and-encrypted-social-applications)
+
+Cong yin si dao she jiao: Web3 xu yao yi zhan shi jia mi she jiao ying yong
+
+BlockTop
+
+Dec 17, 2025 Chinese News
+
+This Chinese article positions SimpleX alongside Session as representing truly decentralized privacy communication in the Web3 ecosystem. It highlights Vitalik Buterin's donation of 128 ETH to SimpleX and describes the platform's elimination of phone numbers, emails, or usernames in favor of the SimpleX Messaging Protocol, calling it potential "killer-level infrastructure" for the crypto industry.
+
+[https://blocktop.cn/newsContent/1/176524](https://blocktop.cn/newsContent/1/176524)
+
+## Ethereum Founder Makes Huge Donation to Messaging App [#](https://simplex.chat/links/#link=ethereum-founder-makes-huge-donation-to-messaging-app)
+
+イーサリアム創設者、メッセージングアプリに巨額寄付
+
+CRYPTO TIMES
+
+Dec 3, 2025 Japanese News
+
+This Japanese crypto news outlet reports on Vitalik Buterin's combined 256 ETH donation to Session and SimpleX Chat. It highlights SimpleX's approach of eliminating permanent user identifiers entirely, using QR codes and invitation links instead, with servers functioning as data conduits that maintain no information about who communicates with whom.
+
+[https://crypto-times.jp/news-ethereum-founder-makes-huge-donation-to-messaging-app/](https://crypto-times.jp/news-ethereum-founder-makes-huge-donation-to-messaging-app/)
+
+## Inside Vitalik's 256 ETH Grants: When Ethereum Falls, Privacy Rises [#](https://simplex.chat/links/#link=inside-vitaliks-256-eth-grants-when-ethereum-falls-privacy-rises)
+
+CryptoSlate
+
+Dec 2, 2025 English News
+
+CryptoSlate covers Vitalik Buterin's 256 ETH total grants to Session and SimpleX Chat, framing it as a signal that privacy infrastructure deserves funding when designed as a foundational architectural feature. The article highlights Buterin's support for metadata-resistant communication systems that operate entirely outside Ethereum's blockchain.
+
+[https://cryptoslate.com/inside-vitaliks-256-eth-grants-when-eth-falls-privacy-rises/](https://cryptoslate.com/inside-vitaliks-256-eth-grants-when-eth-falls-privacy-rises/)
+
+## Vitalik Donated 256 ETH to 2 Chat Apps You've Never Heard Of - What's He Betting On? [#](https://simplex.chat/links/#link=vitalik-donated-256-eth-to-2-chat-apps-youve-never-heard-of-whats-he-betting-on)
+
+Vitalik juan le 256 ge ETH gei 2 ge ni mei ting guo de liao tian ruan jian, dao di zai ya zhu shen me?
+
+BlockWeeks
+
+Nov 28, 2025 Chinese News
+
+This Chinese crypto article analyzes Vitalik's donation of 128 ETH each to Session and SimpleX, timed strategically one day after the EU's Chat Control proposal. It contrasts SimpleX's rejection of tokenization with Session's Web3 SESH token model, and notes Session's token surged over 450% following the announcement while SimpleX views speculation as counterproductive to privacy goals.
+
+[https://blockweeks.com/article/189510](https://blockweeks.com/article/189510)
+
+## Vitalik Donates 128 ETH Each to Session and SimpleX, Supporting Privacy Communication Development [#](https://simplex.chat/links/#link=vitalik-donates-128-eth-each-to-session-and-simplex-supporting-privacy-communica)
+
+Vitalik jin chen xuan bu xiang Session he SimpleX ge juan zeng 128 ETH
+
+TechFlow
+
+Nov 27, 2025 Chinese News
+
+This Chinese crypto newsletter reports on Vitalik Buterin donating 128 ETH each to Session and SimpleX Chat, emphasizing that encrypted communication is crucial for protecting digital privacy. It notes Vitalik identified permissionless account creation and metadata privacy as key priorities, while acknowledging that decentralization, multi-device support, and Sybil/DoS resistance remain significant technical challenges.
+
+[https://www.techflowpost.com/newsletter/detail_106673.html](https://www.techflowpost.com/newsletter/detail_106673.html)
+
+## SimpleX: Ultra-Private Messaging [#](https://simplex.chat/links/#link=simplex-ultra-private-messaging)
+
+SimpleX, mensajeria ultraprivada
+
+Bala Extra
+
+Nov 25, 2025 Spanish Podcast
+
+[https://www.listennotes.com/podcasts/bala-extra/simplex-mensajer%C3%ADa-z3pHYeVJcA2/](https://www.listennotes.com/podcasts/bala-extra/simplex-mensajer%C3%ADa-z3pHYeVJcA2/)
+
+## The Next Anonymous Messengers After Signal: Session and SimpleX Chat [#](https://simplex.chat/links/#link=the-next-anonymous-messengers-after-signal-session-and-simplex-chat)
+
+Signalの次に代わる匿名メッセージアプリ・SessionとSimpleX Chat
+
+renaro / note.com
+
+Nov 21, 2025 Japanese Comparison
+
+This Japanese article positions Session and SimpleX as the next anonymous messengers after Signal, whose mandatory phone number requirement is its main weakness. SimpleX is presented as the most anonymous option due to having no user ID whatsoever, though it requires the additional Orbot app for maximum privacy, making Session more convenient for baseline anonymity.
+
+[https://note.com/renaro/n/n8b3c9af1899f](https://note.com/renaro/n/n8b3c9af1899f)
+
+## Vitalik Buterin Donates $765K in Ethereum to Privacy Messaging Apps [#](https://simplex.chat/links/#link=vitalik-buterin-donates-dollar765k-in-ethereum-to-privacy-messaging-apps)
+
+Decrypt
+
+Nov 2025 English News
+
+Decrypt reports that Vitalik Buterin donated approximately $765,000 in Ethereum to privacy messaging apps Session and SimpleX. Buterin praised both apps for advancing permissionless account creation and metadata privacy, while acknowledging neither is perfect and both need improvements in user experience and security.
+
+[https://decrypt.co/350253/vitalik-buterin-donates-765k-in-ethereum-to-privacy-messaging-apps](https://decrypt.co/350253/vitalik-buterin-donates-765k-in-ethereum-to-privacy-messaging-apps)
+
+## Vitalik Buterin Supports Privacy-Focused Messaging Platforms With Significant Ethereum Donation [#](https://simplex.chat/links/#link=vitalik-buterin-supports-privacy-focused-messaging-platforms-with-significant-et)
+
+Bitcoin.com News
+
+Nov 2025 English News
+
+Bitcoin.com reports that Vitalik Buterin donated 128 ETH (approximately $256,000) to SimpleX Chat and an equal amount to Session, totaling 256 ETH. Buterin emphasized the importance of permissionless account creation and metadata privacy, aiming to advance truly private messaging technologies that protect users from surveillance.
+
+[https://news.bitcoin.com/vitalik-buterin-supports-privacy-focused-messaging-platforms-with-significant-ethereum-donation/](https://news.bitcoin.com/vitalik-buterin-supports-privacy-focused-messaging-platforms-with-significant-ethereum-donation/)
+
+## Vitalik Donates 128 ETH Each to Privacy Messaging Apps Session and SimpleX Chat [#](https://simplex.chat/links/#link=vitalik-donates-128-eth-each-to-privacy-messaging-apps-session-and-simplex-chat)
+
+ヴィタリック、プライバシー重視のメッセージアプリ「Session」「SimpleX Chat」に各128ETHを寄付
+
+New Economy / Gentosha
+
+Nov 2025 Japanese News
+
+This Japanese article reports on Vitalik Buterin's donation of 128 ETH each to Session and SimpleX Chat on November 27, 2025. It quotes Buterin saying encrypted messaging is critical for digital privacy, and notes he identified permissionless account creation and metadata privacy as key development priorities, while acknowledging both apps have not yet achieved ideal user experience.
+
+[https://www.neweconomy.jp/posts/521981](https://www.neweconomy.jp/posts/521981)
+
+## Donating 256 ETH: Vitalik's Bet on Privacy Communication - Why Session and SimpleX? [#](https://simplex.chat/links/#link=donating-256-eth-vitaliks-bet-on-privacy-communication-why-session-and-simplex)
+
+Juan zeng 256 ETH, Vitalik ya zhu yin si tong xun: wei shen me shi Session he SimpleX?
+
+BlockBeats
+
+Nov 2025 Chinese News
+
+This Chinese crypto outlet analyzes Vitalik's 256 ETH donation to Session and SimpleX, explaining SimpleX's radical approach of using one-directional message queues with no global user IDs. It contrasts Session's Web3 token model with SimpleX's rejection of tokenization, and notes the donation was timed one day after the EU's Chat Control proposal threatening end-to-end encryption.
+
+[https://www.theblockbeats.info/news/60368](https://www.theblockbeats.info/news/60368)
+
+## Ethereum Founder Donates R$4.2 Million to Privacy-Focused Messengers [#](https://simplex.chat/links/#link=ethereum-founder-donates-rdollar42-million-to-privacy-focused-messengers)
+
+Fundador do Ethereum doa R$ 4,2 milhoes para mensageiros focados em privacidade
+
+LiveCoins
+
+Nov 2025 Portuguese News
+
+This Brazilian article reports that Vitalik Buterin donated 128 ETH (approximately R$2.1 million) to SimpleX Chat as part of a larger donation to privacy-focused messengers. It notes Buterin acknowledged SimpleX still needs to address challenges including multi-device support and defense against Sybil/DoS attacks without requiring phone numbers.
+
+[https://livecoins.com.br/fundador-do-ethereum-doa-r-42-milhoes-para-mensageiros-focados-em-privacidade-baixe-e-use/](https://livecoins.com.br/fundador-do-ethereum-doa-r-42-milhoes-para-mensageiros-focados-em-privacidade-baixe-e-use/)
+
+## Vitalik Buterin Donates ETH to Privacy Apps [#](https://simplex.chat/links/#link=vitalik-buterin-donates-eth-to-privacy-apps)
+
+Coinspeaker
+
+Nov 2025 Japanese News
+
+This Japanese crypto news article reports that Vitalik Buterin donated 128 ETH to SimpleX Chat as part of a privacy-focused initiative. It describes SimpleX's one-way message queue design that eliminates global identifiers and enables account creation without linking personal information like phone numbers.
+
+[https://www.coinspeaker.com/jp/vitalik-buterin-donates-eth-privacy-apps/](https://www.coinspeaker.com/jp/vitalik-buterin-donates-eth-privacy-apps/)
+
+## Yahoo Japan: Vitalik Buterin Donation Coverage [#](https://simplex.chat/links/#link=yahoo-japan-vitalik-buterin-donation-coverage)
+
+Yahoo Japan News
+
+Nov 2025 Japanese News
+
+[https://news.yahoo.co.jp/articles/a55ac83411dcaca913007857948d335b0ed4d21a](https://news.yahoo.co.jp/articles/a55ac83411dcaca913007857948d335b0ed4d21a)
+
+## SimpleX Chat: The First Messaging App with No User Identifiers - Privacy by Design [#](https://simplex.chat/links/#link=simplex-chat-the-first-messaging-app-with-no-user-identifiers-privacy-by-design)
+
+BrightCoding
+
+Sep 18, 2025 English Review
+
+Bright Coding presents SimpleX Chat as a privacy-by-design platform that eliminates user identifiers entirely, using pairwise temporary identifiers for each conversation and end-to-end encryption with the double ratchet algorithm. The article highlights decentralized communication through user-hosted relay servers and spam prevention through opt-in contact invitations.
+
+[https://www.blog.brightcoding.dev/2025/09/18/simplex-chat-the-first-messaging-app-with-no-user-identifiers-privacy-by-design/](https://www.blog.brightcoding.dev/2025/09/18/simplex-chat-the-first-messaging-app-with-no-user-identifiers-privacy-by-design/)
+
+## Privacy Protection: Instant Messaging [#](https://simplex.chat/links/#link=privacy-protection-instant-messaging)
+
+Hacking Articles
+
+Sep 17, 2025 English Guide
+
+This security-focused article describes SimpleX Chat as a privacy-focused messaging network that keeps profile and contact information hidden from its servers, using proprietary protocols designed with privacy as a core principle. It recommends SimpleX for lightweight, decentralized communication and anonymous use without central servers, while noting it may lack some advanced features compared to more established platforms.
+
+[https://www.hackingarticles.in/privacy-protection-instant-messaging/](https://www.hackingarticles.in/privacy-protection-instant-messaging/)
+
+## Discover the Best Secure Messaging Apps in 2025 [#](https://simplex.chat/links/#link=discover-the-best-secure-messaging-apps-in-2025)
+
+Decouvrez les Meilleures Applications de Messagerie Securisee en 2025
+
+Ca Marche Ca Fonctionne
+
+Aug 26, 2025 French Comparison
+
+This French-language guide on secure messaging apps describes SimpleX Chat as minimalist while offering advanced features, particularly its incognito mode that generates random identifiers for each conversation. SimpleX receives less detailed coverage than Signal, which is positioned as the top security leader in the article.
+
+[https://www.camarchecafonctionne.com/decouvrez-les-meilleures-applications-de-messagerie-securisee-en-2025/](https://www.camarchecafonctionne.com/decouvrez-les-meilleures-applications-de-messagerie-securisee-en-2025/)
+
+## SimpleX Chat 6.4.3: New Features and Jack Dorsey's Support [#](https://simplex.chat/links/#link=simplex-chat-643-new-features-and-jack-dorseys-support)
+
+SimpleX Chat publie sa version 6.4.3 : une messagerie privee toujours plus aboutie
+
+SysKB
+
+Aug 20, 2025 French News
+
+This French tech site covers SimpleX Chat version 6.4.3, noting new features including bot support via commands, hypertext links in Markdown, and automatic removal of link tracking parameters. The article also mentions the project's $1.3 million funding round backed by Jack Dorsey in August 2024.
+
+[https://syskb.com/simplex-chat-6-4-3-nouveautes/](https://syskb.com/simplex-chat-6-4-3-nouveautes/)
+
+## WhatsApp and Telegram Alternative: Full Guide to Decentralized Chats [#](https://simplex.chat/links/#link=whatsapp-and-telegram-alternative-full-guide-to-decentralized-chats)
+
+Alternativa WhatsApp i Telegram: polnyj gid po detsentralizovannym chatam
+
+SecurityLab.ru
+
+Aug 14, 2025 Russian Guide
+
+This Russian guide to decentralized chat alternatives describes SimpleX as using temporary anonymous message queue identifiers instead of traditional accounts, with no phone numbers or emails required. It notes the unfamiliar interaction model may confuse newcomers and potential delivery delays exist, but ranks SimpleX highly for anonymity and metadata protection.
+
+[https://www.securitylab.ru/analytics/562397.php](https://www.securitylab.ru/analytics/562397.php)
+
+## Best Secure Messaging Apps 2025: Private Chat Reviews [#](https://simplex.chat/links/#link=best-secure-messaging-apps-2025-private-chat-reviews)
+
+Tileris
+
+Jul 30, 2025 English Comparison
+
+[https://www.youtube.com/watch?v=GH4u8pQLY90](https://www.youtube.com/watch?v=GH4u8pQLY90)
+
+## SimpleX: The Revolution of Private Messaging [#](https://simplex.chat/links/#link=simplex-the-revolution-of-private-messaging)
+
+SimpleX: La Rivoluzione della Messaggistica Privata
+
+aiutocomputerhelp.it
+
+Jul 16, 2025 Italian Review
+
+This Italian article describes SimpleX as a radical messaging platform that eliminates permanent user identities entirely. Communication occurs through encrypted invitation links creating isolated, non-traceable channels, with no central server knowing anything about users and the ability to self-host relay servers.
+
+[https://www.aiutocomputerhelp.it/simplex-la-rivoluzione-della-messaggistica-privata/](https://www.aiutocomputerhelp.it/simplex-la-rivoluzione-della-messaggistica-privata/)
+
+## Top 10 Secure Messaging Platforms to Replace Telegram in Vietnam 2025 [#](https://simplex.chat/links/#link=top-10-secure-messaging-platforms-to-replace-telegram-in-vietnam-2025)
+
+Top 10 Nen Tang Nhan Tin Bao Mat Thay The Telegram Tai Viet Nam 2025
+
+TuDongChat
+
+May 26, 2025 Vietnamese Article
+
+This Vietnamese article lists SimpleX as the first decentralized, open-source messaging platform that eliminates user identification entirely, requiring no phone number, email, or personal identifier. It positions SimpleX as the highest-security option among Telegram alternatives for Vietnamese users, ideal for journalists, activists, and anyone requiring no digital footprint.
+
+[https://tudongchat.com/blog/nen-tang-nhan-tin-bao-mat/](https://tudongchat.com/blog/nen-tang-nhan-tin-bao-mat/)
+
+## SimpleX for Iran [#](https://simplex.chat/links/#link=simplex-for-iran)
+
+Paskoocheh / ASL19
+
+May 20, 2025 Farsi Review
+
+Paskoocheh, a platform providing circumvention tools for Iranian users, offers SimpleX Chat for Android download. The listing describes SimpleX as a privacy-focused messenger with end-to-end encryption, decentralized architecture, and anonymous communication capabilities, noting it is particularly useful for civil activists, journalists, and anyone requiring confidentiality.
+
+[https://paskoocheh.com/tools/839/android.html](https://paskoocheh.com/tools/839/android.html)
+
+## What Is SimpleX Chat? [#](https://simplex.chat/links/#link=what-is-simplex-chat-french)
+
+Qu'est-ce que SimpleX Chat
+
+No Trust Verify
+
+May 5, 2025 French Article
+
+This French-language article from NoTrustVerify describes SimpleX Chat as the first messaging platform with no identifiers that respects privacy by default. It explains the decentralized architecture using message queues instead of user accounts, and highlights features like Incognito Mode, Live Messages, and separate Chat Profiles for different conversations.
+
+[https://blog.notrustverify.ch/quest-ce-que-simplex-chat](https://blog.notrustverify.ch/quest-ce-que-simplex-chat)
+
+## SimpleX Chat: Decentralized Privacy Messaging App Without User Identifiers [#](https://simplex.chat/links/#link=simplex-chat-decentralized-privacy-messaging-app-without-user-identifiers)
+
+SimpleX Chat - wu xu yong hu biao shi fu de qu zhong xin hua yin si xiao xi ying yong
+
+Kaiyuanapp.cn
+
+Apr 22, 2025 Chinese Review
+
+This Chinese open-source app directory describes SimpleX as a decentralized privacy messaging app that operates without any form of user identifiers. It highlights the SimpleX Messaging Protocol with relay servers that only store encrypted messages temporarily, self-hosting capability, disappearing messages, and anonymous group chats, while noting limitations in voice/video calling, occasional messaging delays, and high Android battery consumption.
+
+[https://kaiyuanapp.cn/simplex-chat-%E6%97%A0%E9%9C%80%E7%94%A8%E6%88%B7%E6%A0%87%E8%AF%86%E7%AC%A6%E7%9A%84%E5%8E%BB%E4%B8%AD%E5%BF%83%E5%8C%96%E9%9A%90%E7%A7%81%E6%B6%88%E6%81%AF%E5%BA%94%E7%94%A8/](https://kaiyuanapp.cn/simplex-chat-%E6%97%A0%E9%9C%80%E7%94%A8%E6%88%B7%E6%A0%87%E8%AF%86%E7%AC%A6%E7%9A%84%E5%8E%BB%E4%B8%AD%E5%BF%83%E5%8C%96%E9%9A%90%E7%A7%81%E6%B6%88%E6%81%AF%E5%BA%94%E7%94%A8/)
+
+## SimpleX: The Safest Instant Messaging App? [#](https://simplex.chat/links/#link=simplex-the-safest-instant-messaging-app)
+
+Free.com.tw
+
+Mar 26, 2025 Chinese (Tr.) Review
+
+This Taiwanese article introduces SimpleX as a privacy-focused messaging app launched in 2020 that requires no phone number or email, using decentralized networking instead of a single server. It notes the spam prevention benefit of link-based contact sharing and mentions the desktop version requires smartphone pairing, while flagging the small user base and lack of Traditional Chinese localization.
+
+[https://free.com.tw/simplex/](https://free.com.tw/simplex/)
+
+## SimpleX Chat Tutorial Part 2: Fun Features [#](https://simplex.chat/links/#link=simplex-chat-tutorial-part-2-fun-features)
+
+SimpleX Chat jian yi jiao cheng di er dan
+
+BHB Community
+
+Mar 20, 2025 Chinese Guide
+
+This Chinese tutorial covers SimpleX Chat setup and advanced features including post-quantum encryption, database password creation, server provider selection, security code verification, and group management. It notes SimpleX has no message recall function except for group admins, voice/video calls require VPN access, and file sizes are limited to 1GB.
+
+[https://boyshelpboys.com/thread-6844.htm](https://boyshelpboys.com/thread-6844.htm)
+
+## SimpleX Network: Power to the People [#](https://simplex.chat/links/#link=simplex-network-power-to-the-people)
+
+SimpleX Chat
+
+Feb 11, 2025 English Livestream
+
+[https://www.youtube.com/watch?v=Uez2mfVGU7s](https://www.youtube.com/watch?v=Uez2mfVGU7s)
+
+## SimpleX Chat Review - Secure and Private Messaging? [#](https://simplex.chat/links/#link=simplex-chat-review-secure-and-private-messaging)
+
+HTR
+
+Feb 10, 2025 English Review
+
+[https://www.youtube.com/watch?v=rGrF1M7x0Nk](https://www.youtube.com/watch?v=rGrF1M7x0Nk)
+
+## Secure and Decentralized Chat Without Phone Number or Accounts [#](https://simplex.chat/links/#link=secure-and-decentralized-chat-without-phone-number-or-accounts)
+
+Chat securizat si descentralizat, fara numar de telefon sau conturi, cu aplicatia de mesagerie SimpleX Chat
+
+Romica Prihor
+
+Feb 2025 Romanian Guide
+
+This Romanian blog post promotes SimpleX as a revolution in secure and decentralized messaging without phone numbers or accounts. It provides installation instructions for Android, iOS, and desktop, and covers group management through invitation links with moderation features, positioning SimpleX as ideal for those prioritizing communication privacy without compromises.
+
+[https://romicaprihor.blogspot.com/2025/02/simplex-chat-revolutia-mesageriei.html](https://romicaprihor.blogspot.com/2025/02/simplex-chat-revolutia-mesageriei.html)
+
+## Best Encrypted Chat Apps for 2025 [#](https://simplex.chat/links/#link=best-encrypted-chat-apps-for-2025)
+
+Nay-dobrite prilozheniya za kriptiran chat na 2025
+
+Questona.com
+
+Jan 29, 2025 Bulgarian Comparison
+
+This Bulgarian article on encrypted chat apps describes SimpleX as suitable for additional privacy, claiming greater anonymity than Briar because it uses no ID numbers. It notes user names change constantly in group chats and supports disappearing messages, but flags an extremely small user base and server reliability issues as significant practical drawbacks.
+
+[https://questona.com/kriptiran-chat/](https://questona.com/kriptiran-chat/)
+
+## Improving SimpleX With Evgeny From SimpleX and Daniel Keller From Flux [#](https://simplex.chat/links/#link=improving-simplex-with-evgeny-from-simplex-and-daniel-keller-from-flux)
+
+Opt Out Podcast
+
+Jan 24, 2025 English Podcast
+
+This Opt Out Podcast episode features Evgeny from SimpleX and Dan Keller from Flux discussing improvements to SimpleX Chat, including quantum-resistant encryption and privacy-preserving content moderation. The conversation also covers a new chat relay approach developed collaboratively between SimpleX and Flux, along with SimpleX's network operator monetization plans.
+
+[https://optoutpod.com/episodes/improving-simplex/](https://optoutpod.com/episodes/improving-simplex/)
+
+## SimpleX Chat: The Libertarian WhatsApp [#](https://simplex.chat/links/#link=simplex-chat-the-libertarian-whatsapp)
+
+SimpleX Chat - Whatsapp libertario
+
+Paranoia
+
+Jan 9, 2025 Portuguese Guide
+
+[https://www.youtube.com/watch?v=4sOvaD-YZLU](https://www.youtube.com/watch?v=4sOvaD-YZLU)
+
+## Best WhatsApp Alternatives 2025 [#](https://simplex.chat/links/#link=best-whatsapp-alternatives-2025)
+
+Tuta Blog
+
+2025 English Comparison
+
+Tuta designates SimpleX as the "best decentralized" WhatsApp alternative, highlighting that it requires no phone number or ID for registration and uses a decentralized network where each chat creates unique fingerprints to prevent connection mapping. The article calls it a must-try for those whose personal well-being and safety demand a greater amount of privacy, while noting its smaller user base compared to competitors.
+
+[https://tuta.com/blog/best-whatsapp-alternatives-privacy](https://tuta.com/blog/best-whatsapp-alternatives-privacy)
+
+## Best WhatsApp Alternatives for Privacy [#](https://simplex.chat/links/#link=best-whatsapp-alternatives-for-privacy)
+
+Proton Blog
+
+2025 English Comparison
+
+Proton's blog highlights SimpleX Chat's radical privacy approach of requiring no phone number, email, or username to create an account, using one-time invitation links instead of a central user directory. The article notes that SimpleX encrypts both messages and metadata and has undergone independent security audits, but faces limitations including a small user base and reports of misuse by extremist groups.
+
+[https://proton.me/blog/whatsapp-alternatives](https://proton.me/blog/whatsapp-alternatives)
+
+## SimpleX Chat: Privacy-Friendly Messenger for Maximum Privacy [#](https://simplex.chat/links/#link=simplex-chat-privacy-friendly-messenger-for-maximum-privacy)
+
+SimpleX Chat - Datenschutzfreundlicher Messenger fur maximale Privatsphare
+
+Digital Unplug Schweiz
+
+2025 (est.) German Guide
+
+This German-language privacy site describes SimpleX Chat as an open-source messenger that completely eliminates user IDs and stores data locally on devices. It details the Double-Ratchet Protocol encryption, temporary connection links, decentralized proxy server routing with optional Tor integration, and cross-platform availability across iOS, Android, Windows, macOS, and Linux.
+
+[https://digitalunplug.ch/simplex.php](https://digitalunplug.ch/simplex.php)
+
+## Anonymous Messaging App SimpleX Chat: Setup and Usage Guide [#](https://simplex.chat/links/#link=anonymous-messaging-app-simplex-chat-setup-and-usage-guide)
+
+ID不要の匿名メッセージアプリ「SimpleX Chat」の使い方
+
+VPN Taizen
+
+2025 (updated) Japanese Guide
+
+This Japanese setup guide describes SimpleX as having the highest privacy protection among messaging apps, explaining its encrypted queue system where servers cannot know who communicates with whom. The reviewer provides detailed instructions for profiles, contact management, and Tor integration, but criticizes the interface as "terrible" with confusing design and iOS stability issues.
+
+[https://vpn-taizen.com/how_to_use_anonymous_messaging_app_simplex_chat_that_doesnt_require_id/](https://vpn-taizen.com/how_to_use_anonymous_messaging_app_simplex_chat_that_doesnt_require_id/)
+
+## Setting Up SimpleX As Your Private Messenger [#](https://simplex.chat/links/#link=setting-up-simplex-as-your-private-messenger)
+
+Daniel's Blog
+
+2025 English Guide
+
+This blog post walks through self-hosting a SimpleX SMP server with Traefik and Docker after the author abandoned WhatsApp over privacy concerns. It highlights SimpleX's invite-link-based connections and decentralized relays that do not reveal participant information, while honestly noting the desktop app requires an active smartphone connection and lacks a web interface.
+
+[https://xfuture-blog.com/posts/setting-up-simplex-as-your-private-messenger/](https://xfuture-blog.com/posts/setting-up-simplex-as-your-private-messenger/)
+
+## I Used Anonymous Chat Tools for a Week: These 3 Are Truly Safe [#](https://simplex.chat/links/#link=i-used-anonymous-chat-tools-for-a-week-these-3-are-truly-safe)
+
+Wo yong le yi zhou ni ming liao tian gong ju, fa xian zhe 3 ge cai shi zhen zheng de an quan
+
+Zhihu
+
+2025 Chinese Review
+
+This Chinese article reviews three anonymous messaging tools - Session, SimpleX Chat, and TWT - from a week-long hands-on test. SimpleX is praised for its zero-metadata design where even the server cannot know who is communicating, with support for text, voice, and groups, but criticized for requiring manual connection-code sharing and a developer-oriented interface that makes onboarding friends difficult.
+
+[https://zhuanlan.zhihu.com/p/1916814606019584862](https://zhuanlan.zhihu.com/p/1916814606019584862)
+
+## Introducing TorGuard's New Private VPN Cloud App: SimpleX Server [#](https://simplex.chat/links/#link=introducing-torguards-new-private-vpn-cloud-app-simplex-server)
+
+TorGuard
+
+2025 (est.) English Service
+
+[https://blog.torguard.net/introducing-torguards-new-private-vpn-cloud-app-simplex-server/](https://blog.torguard.net/introducing-torguards-new-private-vpn-cloud-app-simplex-server/)
+
+## SimpleX Chat Hosting and Services [#](https://simplex.chat/links/#link=simplex-chat-hosting-and-services)
+
+Taurix IT
+
+2025 (est.) English Service
+
+Taurix IT offers managed SimpleX Chat hosting services, including hosting their own SMP servers in separate locations and providing setup assistance for clients who want to self-host. The page emphasizes that SimpleX protects metadata which competitors like Signal and WhatsApp fail to adequately safeguard, making it particularly valuable for whistleblowers, journalists, and activists.
+
+[https://www.taurix.net/simplex-chat/](https://www.taurix.net/simplex-chat/)
+
+## Taurix SimpleX Customer Service Bot [#](https://simplex.chat/links/#link=taurix-simplex-customer-service-bot)
+
+Taurix IT
+
+2025 (est.) English Service
+
+This repository contains a Python-based customer service bot for SimpleX Chat that joins a specified control group and announces newly created customer chats. Control group members can then use commands to join customer conversations, automating the connection between customer service representatives and incoming inquiries.
+
+[https://code.taurix.net/TaurixIT/simplex-customerservicebot](https://code.taurix.net/TaurixIT/simplex-customerservicebot)
+
+## SimpleX SMP Server Setup Guide [#](https://simplex.chat/links/#link=simplex-smp-server-setup-guide)
+
+Freedom Lab NYC
+
+2025 (est.) English Guide
+
+FreedomLab provides a tutorial for self-hosting a SimpleX SMP (Simple Messaging Protocol) server on a Debian/Ubuntu VPS with Tor support. The guide covers installation steps for running your own private, decentralized messaging relay server as part of the SimpleX network.
+
+[https://freedomlab.nyc/resources/simplex-smp/](https://freedomlab.nyc/resources/simplex-smp/)
+
+## SimpleX Communities on Monerica [#](https://simplex.chat/links/#link=simplex-communities-on-monerica)
+
+Monerica
+
+2025 (est.) English Review
+
+This Monerica directory page lists several Monero-focused SimpleX Chat communities spanning multiple languages and regions, including groups for Monero discussion in Slovenian, German, Italian, and Hebrew. It includes an automated bot that sends hourly Monero price updates via SimpleX. Monerica is established in 2022.
+
+[https://monerica.com/communities/simplex](https://monerica.com/communities/simplex)
+
+## SimpleX Chat: Censorship-Resistant Communication [#](https://simplex.chat/links/#link=simplex-chat-censorship-resistant-communication)
+
+SplinterCon
+
+2025 (est.) English Review
+
+The SplinterCon anti-censorship project page describes SimpleX as a decentralized messenger that operates without user IDs, using end-to-end encryption for messages and file transfers. It highlights that SimpleX can run on the Tor network and allows users to deploy their own servers, with messages routed through servers that can operate without persistence.
+
+[https://splintercon.net/project/simplex-chat/](https://splintercon.net/project/simplex-chat/)
+
+## Sofwul.cz: E-Commerce with SimpleX Contact [#](https://simplex.chat/links/#link=sofwulcz-e-commerce-with-simplex-contact)
+
+Sofwul
+
+2025 (est.) Czech Service
+
+This Czech e-commerce site lists SimpleX as one of several encrypted messaging contact options for reaching their customer support, alongside Threema, Session, Jami, and Teleguard.
+
+[https://www.sofwul.cz/kontakty-messengery](https://www.sofwul.cz/kontakty-messengery)
+
+## NBTV Community on SimpleX [#](https://simplex.chat/links/#link=nbtv-community-on-simplex)
+
+NBTV / Ludlow Institute
+
+2025 (est.) English Community
+
+The Ludlow Institute (NBTV) offers SimpleX as one of several community communication platforms alongside Signal and Element, describing it as an end-to-end encrypted messaging app for real-time discussions with other NBTV community members.
+
+[https://ludlowinstitute.org/community](https://ludlowinstitute.org/community)
+
+## Taurix "tellme" Bot [#](https://simplex.chat/links/#link=taurix-tellme-bot)
+
+Taurix IT
+
+2025 (est.) English Service
+
+TellMe is a notification system that monitors events (completed processes, server uptime, etc.) and sends alerts through SimpleX Chat or Matrix via websockets. It supports custom messages, process monitoring, periodic command output watching, and host ping availability tracking.
+
+[https://code.taurix.net/TaurixIT/tellme](https://code.taurix.net/TaurixIT/tellme)
+
+## BitList.co Bitcointalk Notification Bot [#](https://simplex.chat/links/#link=bitlistco-bitcointalk-notification-bot)
+
+BitList.co
+
+2025 (est.) English Service
+
+This Bitcointalk thread presents a notification bot for SimpleX Chat that monitors the forum for merit awards, mentions, quotes, specific users, topics, and keyword phrases. The developer notes that due to SimpleX's decentralized architecture, notifications may experience delays compared to Telegram alternatives, and data is stored for retry when users aren't connected.
+
+[https://bitcointalk.org/index.php?topic=5535681.0](https://bitcointalk.org/index.php?topic=5535681.0)
+
+## SimpleX Without Tears: Wrapped in Onion, Served via Tor [#](https://simplex.chat/links/#link=simplex-without-tears-wrapped-in-onion-served-via-tor)
+
+nemental.de
+
+2025 (est.) English Guide
+
+This guide explains how to host a SimpleX SMP server as a Tor hidden service using Docker containers, making the relay accessible only through .onion addresses. It notes that while SimpleX already has strong privacy by design, adding Tor hides the server's public IP and eliminates DNS exposure, pulling the relay further out of reach of traditional tracking.
+
+[https://nemental.de/simplex-without-tears-wrapped-in-onion-served-via-tor/](https://nemental.de/simplex-without-tears-wrapped-in-onion-served-via-tor/)
+
+## SimpleX Theme Archive [#](https://simplex.chat/links/#link=simplex-theme-archive)
+
+SimpleX-Themes
+
+2025 (est.) English Community
+
+This community-maintained archive offers over 100 downloadable SimpleX Chat themes with preview screenshots, ranging from dark modes (AMOLED Black, Dracula) to colorful designs (Aurora Sunset, Catppuccin, neon synthwave). It is an independent community project not affiliated with SimpleX Chat Ltd, and users can submit their own custom themes.
+
+[https://slcw.github.io/SimpleX-Themes/](https://slcw.github.io/SimpleX-Themes/)
+
+## My Experience With SimpleX Chat: Is It the Ultimate Open Source Private Messaging App? [#](https://simplex.chat/links/#link=my-experience-with-simplex-chat-is-it-the-ultimate-open-source-private-messaging)
+
+It's FOSS
+
+Dec 2024 English Review
+
+It's FOSS presents a highly positive experience with SimpleX Chat, praising its no-ID signup, quantum-resistant encryption, and intuitive messaging features. The main drawback noted was buggy video calls with audio and quality issues, but overall the reviewer concludes SimpleX sets a new standard for secure communication.
+
+[https://itsfoss.com/news/simplex-chat/](https://itsfoss.com/news/simplex-chat/)
+
+## These Are the Most Secure Messaging Apps According to a Criminologist [#](https://simplex.chat/links/#link=these-are-the-most-secure-messaging-apps-according-to-a-criminologist)
+
+Estas son las aplicaciones de mensajeria mas seguras segun una criminologa
+
+Noticias de Navarra
+
+Nov 25, 2024 Spanish News
+
+This Spanish news article reports that criminologist Maria Aperador highlights SimpleX as the most secure messaging application, citing its lack of user identifiers (not even random ones), end-to-end encryption, and impossibility of data tracking. She emphasizes that SimpleX contains no metadata and the app doesn't know who you are or where messages originate.
+
+[https://www.noticiasdenavarra.com/ciencia-y-tecnologia/2024/11/25/estas-son-aplicaciones-mensajeria-mas-seguras-segun-una-criminologa-8972947.html](https://www.noticiasdenavarra.com/ciencia-y-tecnologia/2024/11/25/estas-son-aplicaciones-mensajeria-mas-seguras-segun-una-criminologa-8972947.html)
+
+## Encrypted Communication Between Programs and Mobile Devices [#](https://simplex.chat/links/#link=encrypted-communication-between-programs-and-mobile-devices)
+
+Juraj Bednar
+
+Nov 24, 2024 English Guide
+
+Juraj Bednar chose SimpleX as his preferred solution for sending encrypted notifications between programs and mobile devices, valuing its lack of account creation requirements and absence of spam. He uses helper functions to send messages and files from scripts, while noting SimpleX still has bugs and does not guarantee delivery if the program finishes before transmission completes.
+
+[https://juraj.bednar.io/en/blog-en/2024/11/24/encrypted-communication-between-programs-and-mobile-devices/](https://juraj.bednar.io/en/blog-en/2024/11/24/encrypted-communication-between-programs-and-mobile-devices/)
+
+## SimpleX: Messaging With Total Privacy [#](https://simplex.chat/links/#link=simplex-messaging-with-total-privacy)
+
+SimpleX: mensajeria con total privacidad
+
+VeraSoul
+
+Nov 19, 2024 Spanish Review
+
+This Spanish-language article presents SimpleX Chat as a highly secure messaging app that requires no user IDs, unlike Telegram or Signal. It highlights the app's use of its own SMP protocol, end-to-end encryption, decentralized architecture, and the option for users to choose between SimpleX servers or self-host alternatives.
+
+[https://verasoul.com/simplex-mensajeria-con-total-privacidad.html](https://verasoul.com/simplex-mensajeria-con-total-privacidad.html)
+
+## Messenger for Paranoids: Configuring SimpleX Chat [#](https://simplex.chat/links/#link=messenger-for-paranoids-configuring-simplex-chat)
+
+Мессенджер для параноиков. Настраиваем SimpleX Chat
+
+Первый отдел
+
+Nov 3, 2024 Russian Guide
+
+[https://www.youtube.com/watch?v=3UcejFJ3TY0](https://www.youtube.com/watch?v=3UcejFJ3TY0)
+
+## An Anonymous Messenger: A Mandatory Standard for Every Person [#](https://simplex.chat/links/#link=an-anonymous-messenger-a-mandatory-standard-for-every-person)
+
+Анонимный мессенджер - обязательный стандарт для каждого человека
+
+Habr
+
+Nov 2024 Russian Article
+
+This Russian-language article argues that anonymous messaging with strong encryption should be a standard necessity for everyone, as governments increasingly surveil communications. SimpleX Chat is highlighted as innovative for being the first messenger without user identifiers, using temporary anonymous paired identifiers for each connection that make it impossible to correlate anonymous profiles with real identities.
+
+[https://habr.com/ru/articles/851866/](https://habr.com/ru/articles/851866/)
+
+## Security in Instant Messaging Services [#](https://simplex.chat/links/#link=security-in-instant-messaging-services)
+
+Seguridad en servicios de mensajeria instantanea
+
+Colectivo 406
+
+Oct 27, 2024 Spanish Guide
+
+This Spanish security guide describes SimpleX Chat as using unidirectional message queues with end-to-end encryption including post-quantum algorithms, where servers act only as message bridges with minimal knowledge. It notes SimpleX is fully self-hostable unlike Signal, but acknowledges the complex changing queue addresses make maintaining long-term contacts more difficult.
+
+[https://406.neocities.org/a/apps_mensajeria/](https://406.neocities.org/a/apps_mensajeria/)
+
+## SimpleX Chat Group Chat Tested in Practice [#](https://simplex.chat/links/#link=simplex-chat-group-chat-tested-in-practice)
+
+SimpleX: Gruppenchat-Funktion im Praxistest
+
+Kuketz IT-Security Blog
+
+Oct 14, 2024 German Review
+
+German privacy blogger Mike Kuketz documents significant performance issues with SimpleX's group chat functionality, including substantial message delays where one message sent at 19:39 arrived the next day at 11:50. The founder acknowledged that groups were never designed for more than 50 users, and the article concludes SimpleX is unsuitable for group chats exceeding that limit.
+
+[https://www.kuketz-blog.de/simplex-gruppenchat-funktion-im-praxistest/](https://www.kuketz-blog.de/simplex-gruppenchat-funktion-im-praxistest/)
+
+## Users Flocking to Telegram Alternative Apps [#](https://simplex.chat/links/#link=users-flocking-to-telegram-alternative-apps)
+
+텔레그램 대안 앱으로 몰려가는 이용자들
+
+eKoreaNews
+
+Oct 11, 2024 Korean News
+
+This Korean news article reports on users flocking to Telegram alternatives, positioning SimpleX as the first messenger without user IDs. It notes SimpleX's decentralized architecture and mentions its early funding support from Jack Dorsey, while contextualizing the migration trend against Telegram's policy changes allowing authorities access to user data.
+
+[https://www.ekoreanews.co.kr/news/articleView.html?idxno=75746](https://www.ekoreanews.co.kr/news/articleView.html?idxno=75746)
+
+## SimpleX Chat: A Privacy-Optimized Chat App - Why Telegram Users Are Leaving [#](https://simplex.chat/links/#link=simplex-chat-a-privacy-optimized-chat-app-why-telegram-users-are-leaving)
+
+SimpleX Chat, 개인 정보 보호에 최적화된 채팅 앱, 텔레그램 사용자들이 떠나는 이유
+
+Billionnapkin
+
+Oct 8, 2024 Korean Review
+
+This article frames SimpleX as a privacy-optimized alternative to Telegram, arguing users are migrating due to Telegram's changed data access policies following CEO Pavel Durov's legal issues. The tone is promotional but balanced, acknowledging concerns about potential misuse while endorsing SimpleX for journalists, activists, and privacy-conscious professionals.
+
+[https://billionnapkin.com/simplex-chat/](https://billionnapkin.com/simplex-chat/)
+
+## Why We Recommend SimpleX Now [#](https://simplex.chat/links/#link=why-we-recommend-simplex-now)
+
+Techlore
+
+Oct 7, 2024 English Review
+
+[https://www.youtube.com/watch?v=DVKe8U-n8fU](https://www.youtube.com/watch?v=DVKe8U-n8fU)
+
+## Open-Source SimpleX Chat Succeeds Where Telegram Failed [#](https://simplex.chat/links/#link=open-source-simplex-chat-succeeds-where-telegram-failed-russian)
+
+Чат SimpleX с открытым исходным кодом преуспел там, где Telegram потерпел неудачу
+
+Notebookcheck Russia
+
+Oct 3, 2024 Russian News
+
+This Russian-language Notebookcheck article highlights how SimpleX Chat addresses privacy concerns that Telegram failed to handle, including not requiring phone numbers, using one-way onion routing, allowing users to select their own servers, and providing end-to-end encryption with local device encryption. Unlike Telegram, which made changes after government pressure, SimpleX maintains stronger anonymity protections.
+
+[https://www.notebookcheck-ru.com/CHat-SimpleX-s-otkrytym-iskhodnym-kodom-preuspel-tam-gde-Telegram-poterpel-neudachu.897103.0.html](https://www.notebookcheck-ru.com/CHat-SimpleX-s-otkrytym-iskhodnym-kodom-preuspel-tam-gde-Telegram-poterpel-neudachu.897103.0.html)
+
+## Open-Source SimpleX Chat Succeeds Where Telegram Failed [#](https://simplex.chat/links/#link=open-source-simplex-chat-succeeds-where-telegram-failed-chinese)
+
+开源 SimpleX Chat 成功弥补了 Telegram 的不足
+
+Notebookcheck China
+
+Oct 3, 2024 Chinese News
+
+This Chinese Notebookcheck article argues SimpleX succeeds where Telegram failed on privacy. It highlights that SimpleX requires no phone numbers, uses incognito mode with auto-generated usernames, employs one-way onion routing, and allows users to set up their own servers. The article notes unlimited group sizes but acknowledges SimpleX currently lacks widespread adoption.
+
+[https://www.notebookcheck-cn.com/SimpleX-Chat-Telegram.897088.0.html](https://www.notebookcheck-cn.com/SimpleX-Chat-Telegram.897088.0.html)
+
+## Open-Source SimpleX Chat Succeeds Where Telegram Failed [#](https://simplex.chat/links/#link=open-source-simplex-chat-succeeds-where-telegram-failed-english)
+
+Notebookcheck
+
+Oct 2, 2024 English News
+
+Notebookcheck argues that SimpleX Chat addresses privacy failures inherent in Telegram, highlighting that SimpleX requires no phone number, uses end-to-end encryption with onion routing, and allows users to select their own servers. The article notes that SimpleX operates in incognito mode by default and that even SimpleX itself cannot determine where messages originate.
+
+[https://www.notebookcheck.net/Open-source-SimpleX-Chat-succeeds-where-Telegram-failed.896988.0.html](https://www.notebookcheck.net/Open-source-SimpleX-Chat-succeeds-where-Telegram-failed.896988.0.html)
+
+## SimpleX Chat - Next Level Private Messaging [#](https://simplex.chat/links/#link=simplex-chat-next-level-private-messaging)
+
+Mental Outlaw
+
+Oct 1, 2024 English Review
+
+[https://www.youtube.com/watch?v=0cRu98XSap0](https://www.youtube.com/watch?v=0cRu98XSap0)
+
+## SimpleX Chat v6.1: Better Calls, iOS Notifications, UX Improvements [#](https://simplex.chat/links/#link=simplex-chat-v61-better-calls-ios-notifications-ux-improvements)
+
+NoBs Bitcoin
+
+Oct 2024 English News
+
+No BS Bitcoin covers SimpleX Chat v6.1, which enhances call functionality with camera activation and screen sharing from the desktop app during voice calls. The release also resolves iOS notification delivery problems, improves connectivity, and features a redesigned conversation layout with faster message operations.
+
+[https://www.nobsbitcoin.com/simplex-chat-v6-1-0/](https://www.nobsbitcoin.com/simplex-chat-v6-1-0/)
+
+## Open-Source SimpleX Chat Succeeds Where Telegram Failed [#](https://simplex.chat/links/#link=open-source-simplex-chat-succeeds-where-telegram-failed-portuguese)
+
+O SimpleX Chat de codigo aberto tem sucesso onde o Telegram falhou
+
+Notebookcheck Portugal
+
+Oct 2024 Portuguese News
+
+This Portuguese Notebookcheck article contrasts SimpleX with Telegram, emphasizing that SimpleX does not require phone numbers for registration, uses incognito mode and one-way onion routing, and offers end-to-end plus local device encryption. It positions SimpleX's open-source, decentralized approach against Telegram's conflicts with government agencies.
+
+[https://www.notebookcheck.info/O-SimpleX-Chat-de-codigo-aberto-tem-sucesso-onde-o-Telegram-falhou.897026.0.html](https://www.notebookcheck.info/O-SimpleX-Chat-de-codigo-aberto-tem-sucesso-onde-o-Telegram-falhou.897026.0.html)
+
+## SimpleX Chat: The Hidden Portal of Privacy [#](https://simplex.chat/links/#link=simplex-chat-the-hidden-portal-of-privacy)
+
+SimpleX Chat - O Portal Oculto da Privacidade
+
+Paranoia
+
+Oct 2024 Portuguese Review
+
+[https://www.youtube.com/watch?v=CCB9m0T7RIM](https://www.youtube.com/watch?v=CCB9m0T7RIM)
+
+## Goodbye Telegram, Welcome SimpleX! [#](https://simplex.chat/links/#link=goodbye-telegram-welcome-simplex)
+
+Viszlat Telegram, udvozollek SimpleX!
+
+HUP.hu
+
+Oct 2024 Hungarian Community
+
+This Hungarian article shares a user's year-long experience with SimpleX Chat, praising that it requires no email, phone number, username, or password to register. The author describes the SimpleX address system, the Directory Bot for finding public groups, and notes the tradeoff that deleting the app without a database backup means permanently losing your profile and all contacts, while also referencing the Wired article about neo-Nazis on SimpleX and the SimpleX developer's response defending privacy.
+
+[https://hup.hu/node/186622](https://hup.hu/node/186622)
+
+## SimpleX Chat: A Decentralized Messaging App [#](https://simplex.chat/links/#link=simplex-chat-a-decentralized-messaging-app)
+
+SimpleX Chat, un'app di messaggistica decentralizzata
+
+Le Alternative
+
+Sep 18, 2024 Italian Review
+
+This Italian article reviews SimpleX Chat as a completely decentralized messaging app emphasizing anonymity and privacy, with no user IDs and end-to-end encrypted messages that remain on servers only until delivery. It notes support for audio/video calls, message editing, and self-hosted servers, while flagging drawbacks like high battery consumption and account recovery difficulties without backups.
+
+[https://blog.lealternative.net/2024/09/18/simplex-chat-unapp-di-messaggistica-decentralizzata/](https://blog.lealternative.net/2024/09/18/simplex-chat-unapp-di-messaggistica-decentralizzata/)
+
+## Alternatives to Signal and Telegram: Which Secure Messenger to Use Now? [#](https://simplex.chat/links/#link=alternatives-to-signal-and-telegram-which-secure-messenger-to-use-now)
+
+Alternativy Signal i Telegram: kakoj bezopasnyj messendzher ispol'zovat' teper'?
+
+hi-tech.mail.ru
+
+Sep 9, 2024 Russian Review
+
+This Russian tech review highlights SimpleX's complete anonymity through having no telephone numbers or identifiers, and describes its support for audio/video calls, file transfer, disappearing messages, and personal relay servers. It notes all information is stored exclusively on user devices, with messages only temporarily held on relay servers during delivery.
+
+[https://hi-tech.mail.ru/review/114266-alternativy-signal-i-telegram-kakoj-bezopasnyj-messendzher-ispolzovat/](https://hi-tech.mail.ru/review/114266-alternativy-signal-i-telegram-kakoj-bezopasnyj-messendzher-ispolzovat/)
+
+## SimpleX and Matrix Are the Best Messengers. Period. [#](https://simplex.chat/links/#link=simplex-and-matrix-are-the-best-messengers-period)
+
+SimpleX i Matrix to najlepsze komunikatory. Kropka.
+
+Programista Dla Pasji
+
+Sep 5, 2024 Polish Comparison
+
+This Polish article evaluates multiple messengers, praising SimpleX for its decentralization where servers function merely as message relays, requiring no personal data. However, the author ultimately chooses Matrix over SimpleX for daily use due to Matrix's superior multi-device support, while acknowledging SimpleX's elegant simplicity and decentralized design.
+
+[https://programistadlapasji.pl/simplex-i-matrix-to-najlepsze-komunikatory-kropka/](https://programistadlapasji.pl/simplex-i-matrix-to-najlepsze-komunikatory-kropka/)
+
+## Decentralized Messengers: Choosing the Most Secure Way to Communicate [#](https://simplex.chat/links/#link=decentralized-messengers-choosing-the-most-secure-way-to-communicate)
+
+Detsentralizovannyye messendzhery: vybiraem samyj bezopasnyj sposob obshcheniya
+
+SecurityLab.ru
+
+Sep 1, 2024 Russian Guide
+
+This Russian security analysis categorizes SimpleX Chat as a decentralized and anonymous messenger prioritizing minimalism and maximum security. It notes SimpleX provides a high level of anonymity and eliminates metadata exposure, but acknowledges its restricted functionality and relatively low user awareness.
+
+[https://www.securitylab.ru/analytics/551634.php](https://www.securitylab.ru/analytics/551634.php)
+
+## Signal's Brothers: Choosing From Five Most Private and Protected Messengers [#](https://simplex.chat/links/#link=signals-brothers-choosing-from-five-most-private-and-protected-messengers)
+
+Bratya Signal. Vybiraem iz pyati naibolee privatnykh i zashchishchyonnykh messendzherov
+
+Xakep.ru
+
+Aug 27, 2024 Russian Review
+
+This Russian security magazine calls SimpleX "the most interesting messenger in this selection, and also the most mysterious." The article highlights its anonymous registration requiring no phone number, federated architecture allowing user-hosted relay servers, and modern functionality including audio/video calls and disappearing messages.
+
+[https://xakep.ru/2024/08/27/5-private-messengers/](https://xakep.ru/2024/08/27/5-private-messengers/)
+
+## Sharing Several E2EE Open-Source Chat Apps 100x Safer Than Telegram [#](https://simplex.chat/links/#link=sharing-several-e2ee-open-source-chat-apps-100x-safer-than-telegram)
+
+Fen xiang ji ge bi dian bao Telegram an quan 100 bei de duan dui duan jia mi kai yuan liao tian ruan jian
+
+V2EX
+
+Aug 26, 2024 Chinese Community
+
+This Chinese V2EX forum post recommends SimpleX as having the highest encryption strength among reviewed E2EE messaging apps, highlighting that unlike Session's fixed IDs, SimpleX eliminates even fixed identifiers entirely. It notes SimpleX uses temporary anonymous pairing identifiers, creates independent fingerprints per conversation, supports Tor integration, and can be self-hosted.
+
+[https://www.v2ex.com/t/1067954](https://www.v2ex.com/t/1067954)
+
+## Sharing E2EE Open-Source Chat Apps 100x Safer Than Telegram [#](https://simplex.chat/links/#link=sharing-e2ee-open-source-chat-apps-100x-safer-than-telegram)
+
+Fen xiang ji ge bi dian bao Telegram an quan 100 bei de kai yuan liao tian ruan jian
+
+Matters.town
+
+Aug 26, 2024 Chinese Article
+
+This Chinese article recommends several end-to-end encrypted open-source chat apps that are far more secure than Telegram, written in the context of the Telegram founder's detention in France. It explains end-to-end encryption and mentions Session and SimpleX among the recommended alternatives that protect message content from being readable even by the relay servers.
+
+[https://matters.town/a/hvb8p0wepluy](https://matters.town/a/hvb8p0wepluy)
+
+## SimpleX Raises $1.3M From Jack Dorsey and Asymmetric VC, Releases Chat v6.0 [#](https://simplex.chat/links/#link=simplex-raises-dollar13m-from-jack-dorsey-and-asymmetric-vc-releases-chat-v60)
+
+NoBs Bitcoin
+
+Aug 2024 English News
+
+No BS Bitcoin reports that SimpleX Chat secured $1.3 million in pre-seed investment led by Jack Dorsey and Asymmetric Capital Partners. The v6.0 release includes protocol improvements reducing the messages needed for users to connect by half, a redesigned mobile interface, image blur options, and improved moderation tools supporting up to 20 message selections.
+
+[https://www.nobsbitcoin.com/simplex-chat-v6-0/](https://www.nobsbitcoin.com/simplex-chat-v6-0/)
+
+## Anonymous Chat Showdown: Session vs SimpleX [#](https://simplex.chat/links/#link=anonymous-chat-showdown-session-vs-simplex)
+
+匿名チャット対決！Session対SimpleX
+
+Kusaimara Blog
+
+Jul 2024 Japanese Comparison
+
+This Japanese blog post compares Session and SimpleX across recognition, usability, and anonymity. It notes SimpleX avoids user IDs entirely using unique URLs for connections but requires manual Tor activation. The author concludes both tools suffer from limited adoption, arguing that messaging apps require network effects to be practical.
+
+[https://kusaimara.net/2024/07/758](https://kusaimara.net/2024/07/758)
+
+## SimpleX Introduces Enhanced IP Privacy Measures [#](https://simplex.chat/links/#link=simplex-introduces-enhanced-ip-privacy-measures)
+
+Reclaim the Net
+
+Jun 12, 2024 English News
+
+Reclaim The Net covers SimpleX Chat v5.8's private message routing protocol where the forwarding relay is chosen by the sender and the second by the recipient, ensuring neither party can observe the other's IP address. The developers rejected embedding Tor due to latency and metadata correlation issues, instead building their own solution that provides IP protection by default.
+
+[https://reclaimthenet.org/simplex-introduces-enhanced-ip-privacy-measures](https://reclaimthenet.org/simplex-introduces-enhanced-ip-privacy-measures)
+
+## SimpleX Chat v5.8: Private Message Routing [#](https://simplex.chat/links/#link=simplex-chat-v58-private-message-routing)
+
+NoBs Bitcoin
+
+Jun 2024 English News
+
+No BS Bitcoin covers SimpleX Chat v5.8's introduction of private message routing, described as a 2-hop onion routing protocol inspired by Tor that protects both users' IP addresses and transport sessions. The update also adds file reception protections from unknown servers, chat themes with wallpapers, and improved group permissions for admins.
+
+[https://www.nobsbitcoin.com/simplex-chat-v5-8/](https://www.nobsbitcoin.com/simplex-chat-v5-8/)
+
+## Step-by-Step SimpleX Chat Guide [#](https://simplex.chat/links/#link=step-by-step-simplex-chat-guide)
+
+Passo a passo do aplicativo SimpleX Chat
+
+Alex Emidio / Substack
+
+May 26, 2024 Portuguese Guide
+
+This Portuguese step-by-step guide covers SimpleX Chat's backup and data recovery features, including database encryption with user-created passwords and export of encrypted backups. It emphasizes the local-first approach where contacts and messages are stored on the user's device, and warns that the database password cannot be changed if lost.
+
+[https://alexemidio.substack.com/p/passo-a-passo-do-aplicativo-simplexchat](https://alexemidio.substack.com/p/passo-a-passo-do-aplicativo-simplexchat)
+
+## Why I Recommend SimpleX Over Signal and Session [#](https://simplex.chat/links/#link=why-i-recommend-simplex-over-signal-and-session)
+
+巷で話題のSignalやSessionではなくSimpleXをおすすめする理由
+
+vpn53049 / Ameblo
+
+May 19, 2024 Japanese Review
+
+This Japanese blog post advocates for SimpleX over Signal and Session, citing its per-connection one-time IDs, forward secrecy, and post-quantum encryption. The author criticizes Session for lacking forward secrecy and using fixed permanent IDs, and questions Signal's leadership integrity, concluding SimpleX addresses privacy gaps present in both alternatives.
+
+[https://ameblo.jp/vpn53049/entry-12852836589.html](https://ameblo.jp/vpn53049/entry-12852836589.html)
+
+## SimpleX Launches Quantum-Resistant Encryption in Beta [#](https://simplex.chat/links/#link=simplex-launches-quantum-resistant-encryption-in-beta)
+
+Reclaim the Net
+
+Apr 2, 2024 English News
+
+Reclaim The Net reports that SimpleX Chat launched a beta version of quantum-resistant encryption, implementing post-quantum cryptography with an improved quantum-resistant double ratchet algorithm. The article notes the use of fixed 16kb block sizes and lossless compression to prevent traffic analysis, with the feature currently optional for users.
+
+[https://reclaimthenet.org/simplex-chat-launches-quantum-resistant-encryption-in-beta](https://reclaimthenet.org/simplex-chat-launches-quantum-resistant-encryption-in-beta)
+
+## SimpleX Chat v5.7: Quantum Resistant End-to-End Encryption [#](https://simplex.chat/links/#link=simplex-chat-v57-quantum-resistant-end-to-end-encryption)
+
+NoBs Bitcoin
+
+Apr 2024 English News
+
+No BS Bitcoin reports that SimpleX Chat v5.7 introduced quantum-resistant end-to-end encryption for all contacts and message forwarding without revealing the source. The article notes planned third-party security audits and the team's request for community donations to help cover audit costs exceeding $50,000.
+
+[https://www.nobsbitcoin.com/simplex-chat-v5-7-0/](https://www.nobsbitcoin.com/simplex-chat-v5-7-0/)
+
+## Self-Host SimpleX Chat [#](https://simplex.chat/links/#link=self-host-simplex-chat)
+
+Hospeda SimpleX Chat
+
+CLASES DE LINUX
+
+Feb 10, 2024 Spanish Guide
+
+[https://www.youtube.com/watch?v=p1NF68KIt7M](https://www.youtube.com/watch?v=p1NF68KIt7M)
+
+## Self-Hosted SimpleX Chat [#](https://simplex.chat/links/#link=self-hosted-simplex-chat)
+
+Simple Messaging With Unusually Good Privacy
+
+Feb 8, 2024 English Guide
+
+[https://www.youtube.com/watch?v=1zMAGzYBgJY](https://www.youtube.com/watch?v=1zMAGzYBgJY)
+
+## SimpleX: Communication Client for Truly Secure and Anonymous Communication [#](https://simplex.chat/links/#link=simplex-communication-client-for-truly-secure-and-anonymous-communication)
+
+SimpleX - komunikacijski klijent za stvarno sigurnu i anonimnu komunikaciju
+
+Bug.hr
+
+Feb 2, 2024 Croatian Review
+
+This Croatian tech publication describes SimpleX as a highly secure, decentralized messaging app using Double Ratchet encryption with no user identifiers and local-only data storage. It highlights anonymous profiles, self-destructing messages, voice and video calls, and self-hosting capability, with one commenter noting it is "really top for privacy."
+
+[https://www.bug.hr/appdana/simplex-komunikacijski-klijent-za-stvarno-sigurnu-i-anonimnu-komunikaciju-38082](https://www.bug.hr/appdana/simplex-komunikacijski-klijent-za-stvarno-sigurnu-i-anonimnu-komunikaciju-38082)
+
+## Group P2P Chats and the First Messenger Without ID [#](https://simplex.chat/links/#link=group-p2p-chats-and-the-first-messenger-without-id)
+
+Групповые P2P-чаты и первый мессенджер без ID
+
+Habr / GlobalSign
+
+Feb 2024 Russian Article
+
+This Habr article examines group P2P messaging and SimpleX as the first messenger without user IDs, using temporary anonymous paired message queue identifiers unique to each connection. It details incognito mode, decentralized storage, dual-layer encryption, and Tor compatibility, contrasting SimpleX's approach with all existing messengers that rely on some form of user identification.
+
+[https://habr.com/ru/companies/globalsign/articles/792986/](https://habr.com/ru/companies/globalsign/articles/792986/)
+
+## SimpleX Chat: A Private and Encrypted Open-Source Communication Tool Without Any User IDs [#](https://simplex.chat/links/#link=simplex-chat-a-private-and-encrypted-open-source-communication-tool-without-any-)
+
+SimpleX Chat：一个私人且加密的开源通讯工具，没有任何用户 ID
+
+Ababtools
+
+Jan 7, 2024 Chinese Review
+
+This article describes SimpleX Chat as an open-source messaging platform that does not rely on any user identifier, not even random numbers. It highlights Double Ratchet encryption, multiple chat profiles including hidden ones, encrypted voice messages and audio/video calls, secret group chats, and portable encrypted databases, with availability across Android, iOS, and desktop.
+
+[https://ababtools.com/?post=955](https://ababtools.com/?post=955)
+
+## Interview With the Author of SimpleX Chat: The Most Secure Messaging by Design [#](https://simplex.chat/links/#link=interview-with-the-author-of-simplex-chat-the-most-secure-messaging-by-spanish)
+
+Entrevista con el autor de SimpleX Chat: la mensajeria mas segura por diseno
+
+GatoOscuro
+
+2024 Spanish Interview
+
+This Spanish-language interview with SimpleX founder Evgeny Poberezkin covers the project's approach to eliminating user identifiers, addresses concerns about government surveillance and backdoors, and discusses funding from Village Global without compromising independence. Poberezkin emphasizes that adoption, word-of-mouth promotion, and user donations are essential for the project's survival.
+
+[https://gatooscuro.xyz/entrevista-con-el-autor-de-simplex-chat-la-mensajeria-mas-segura-por-diseno/](https://gatooscuro.xyz/entrevista-con-el-autor-de-simplex-chat-la-mensajeria-mas-segura-por-diseno/)
+
+## SimpleX: The Chat Network That Preserves Metadata Privacy [#](https://simplex.chat/links/#link=simplex-the-chat-network-that-preserves-metadata-privacy)
+
+SimpleX, a rede de bate-papo que preserva a privacidade de metadados
+
+Edivaldo Brito
+
+2024 (est.) Portuguese Review
+
+This Portuguese article describes SimpleX as a decentralized, open-source chat network that preserves metadata privacy by using disposable relay nodes and assigning no user identifiers for message routing. It explains that SimpleX employs two layers of end-to-end encryption - double ratchet for forward secrecy and a second layer to protect metadata - along with unidirectional (simplex) message queues that combine the advantages of P2P and server-based architectures.
+
+[https://www.edivaldobrito.com.br/simplex-a-rede-de-bate-papo-que-preserva-a-privacidade-de-metadados/](https://www.edivaldobrito.com.br/simplex-a-rede-de-bate-papo-que-preserva-a-privacidade-de-metadados/)
+
+## SimpleX Is an Alternative to Telegram Focused on Privacy [#](https://simplex.chat/links/#link=simplex-is-an-alternative-to-telegram-focused-on-privacy)
+
+SimpleX e uma alternativa ao Telegram com foco na privacidade
+
+Midia Segura
+
+2024 (est.) Portuguese Review
+
+This Portuguese-language article presents SimpleX as a privacy-focused alternative to Telegram, noting increased user migration following Pavel Durov's arrest and Telegram's policy changes. It highlights SimpleX as the first messaging app without a user ID, email, or phone number, with backing from Jack Dorsey.
+
+[https://midiasegura.com/simplex-e-uma-alternativa-ao-telegram-com-foco-na-privacidade/](https://midiasegura.com/simplex-e-uma-alternativa-ao-telegram-com-foco-na-privacidade/)
+
+## SimpleX Chat: The First Messenger Without User ID [#](https://simplex.chat/links/#link=simplex-chat-the-first-messenger-without-user-id)
+
+Simplex Chat - O primeiro mensageiro sem ID de usuario
+
+Rafael Mesquita / TabNews
+
+2024 (est.) Portuguese Article
+
+This Portuguese-language article highlights SimpleX Chat as a privacy-focused messenger that uses temporary anonymous pairwise message queue identifiers instead of user IDs, phone numbers, or usernames. It explains that this design prevents metadata correlation attacks and that user profiles are stored only on devices, with dual-layer end-to-end encryption and optional Tor connections.
+
+[https://www.tabnews.com.br/RafaelMesquita/simplex-chat-o-primeiro-mensageiro-sem-id-de-usuario](https://www.tabnews.com.br/RafaelMesquita/simplex-chat-o-primeiro-mensageiro-sem-id-de-usuario)
+
+## SimpleX Chat: A Revolutionary Tool for Private and Even Anonymous Communications [#](https://simplex.chat/links/#link=simplex-chat-a-revolutionary-tool-for-private-and-even-anonymous-communications)
+
+SimpleX Chat: A Ferramenta Revolucionaria para Comunicacoes Privadas e ate Anonimas
+
+Coach De Osasco
+
+2024 (est.) Portuguese Review
+
+[https://www.youtube.com/watch?v=fUwPGhSYlLY](https://www.youtube.com/watch?v=fUwPGhSYlLY)
+
+## Exploring SimpleX Chat: A Scriptable, Decentralized Messaging App [#](https://simplex.chat/links/#link=exploring-simplex-chat-a-scriptable-decentralized-messaging-app)
+
+Rick Carlino
+
+2024 English Article
+
+The author explores SimpleX Chat's bot-building capabilities using its CLI application with WebSocket support, finding the process remarkably straightforward and reminiscent of writing IRC scripts with a better UX. The article includes a functional TypeScript example demonstrating how to build chatbots through JSON commands, requiring minimal setup of just downloading an executable and connecting via WebSocket.
+
+[https://rickcarlino.com/2024/simplex-chat-bots.html](https://rickcarlino.com/2024/simplex-chat-bots.html)
+
+## SimpleX Chat: A Damn Private Messaging Service [#](https://simplex.chat/links/#link=simplex-chat-a-damn-private-messaging-service)
+
+SimpleX Chat une messagerie sacrement privee
+
+Siksik
+
+2024 (est.) French Review
+
+[https://siksik.org/simplex-chat-une-messagerie-sacrement-privee/](https://siksik.org/simplex-chat-une-messagerie-sacrement-privee/)
+
+## SimpleX Chat: A New Instant Messaging Application [#](https://simplex.chat/links/#link=simplex-chat-a-new-instant-messaging-application)
+
+SimpleX Chat: Une Nouvelle Application de Messagerie Instantanee
+
+AEKONE
+
+2024 (est.) French Review
+
+[https://aek.one/simplex-chat-une-nouvelle-application-de-messagerie-instantannee/](https://aek.one/simplex-chat-une-nouvelle-application-de-messagerie-instantannee/)
+
+## SimpleX Chat: The Ultra-Private Messaging App Almost Nobody Knows [#](https://simplex.chat/links/#link=simplex-chat-the-ultra-private-messaging-app-almost-nobody-knows)
+
+SimpleX Chat la app de mensajeria ultra privada que casi nadie conoce
+
+RD CIPHER
+
+2024 (est.) Spanish Review
+
+[https://www.youtube.com/watch?v=5vroKXgVZ3Q](https://www.youtube.com/watch?v=5vroKXgVZ3Q)
+
+## SimpleX: Messaging WITHOUT Identifiers [#](https://simplex.chat/links/#link=simplex-messaging-without-identifiers)
+
+SimpleX: mensajeria SIN identificadores
+
+Elurk Informatica
+
+2024 (est.) Spanish Review
+
+[https://www.youtube.com/watch?v=Uit79EFxTAs](https://www.youtube.com/watch?v=Uit79EFxTAs)
+
+## An Overview of Privacy-Focused, Decentralized Instant Messengers [#](https://simplex.chat/links/#link=an-overview-of-privacy-focused-decentralized-instant-messengers)
+
+Marius
+
+2024 (est.) English Article
+
+This privacy-focused blog describes SimpleX as an open-source, decentralized instant messenger that lacks fixed user identifiers, requiring neither a phone number nor a username. However, the author withdrew their recommendation after SimpleX received venture capital funding from Jack Dorsey in August 2024, citing concerns about the investment's influence.
+
+[https://xn--gckvb8fzb.com/an-overview-of-privacy-focused-decentralized-instant-messengers/](https://xn--gckvb8fzb.com/an-overview-of-privacy-focused-decentralized-instant-messengers/)
+
+## SimpleX Chat: Next-Generation Secure Communication Tool Without Identity Verification [#](https://simplex.chat/links/#link=simplex-chat-next-generation-secure-communication-tool-without-identity-verifica)
+
+SimpleX Chat：无需身份识别的下一代安全通讯工具
+
+Huluohu Blog
+
+2024 (est.) Chinese Review
+
+This Chinese article introduces SimpleX Chat as a uniquely private messaging platform that requires no phone number, email, or username of any kind, using shared links instead to establish connections. It highlights SimpleX's core advantages: true anonymity where even the servers cannot know who is talking to whom, end-to-end encryption, decentralized server architecture, open-source transparency, and innovative use of unidirectional message queues with rotating random receive addresses to resist network analysis.
+
+[https://www.huluohu.com/posts/1221/](https://www.huluohu.com/posts/1221/)
+
+## 10 Most Secure Messaging Apps of 2024 [#](https://simplex.chat/links/#link=10-most-secure-messaging-apps-of-2024)
+
+Le 10 app di messaggistica piu sicure del 2024
+
+Moyens I/O Italy
+
+2024 Italian Comparison
+
+[https://it.moyens.net/app/app-messaggistica-piu-sicure-del-signal-session-simplex/](https://it.moyens.net/app/app-messaggistica-piu-sicure-del-signal-session-simplex/)
+
+## Anonymous Chat Without Phone and Email: Online Privacy With Ultra Metadata Annihilation [#](https://simplex.chat/links/#link=anonymous-chat-without-phone-and-email-online-privacy-with-ultra-metadata-annihi)
+
+SIMPLEX: CHAT ANONIMO SEM TELEFONE E EMAIL / PRIVACIDADE ONLINE COM ULTRA ANIQUILACAO DE METADADOS
+
+Leandroibov
+
+2024 (est.) Portuguese Review
+
+[https://www.youtube.com/watch?v=gvVfpPB1srI](https://www.youtube.com/watch?v=gvVfpPB1srI)
+
+## How to Use SimpleX Private Chat Without Identification [#](https://simplex.chat/links/#link=how-to-use-simplex-private-chat-without-identification)
+
+Como usar o SimpleX chat privado sem identificacao
+
+Prometheus HODL
+
+2024 (est.) Portuguese Guide
+
+[https://www.youtube.com/watch?v=JMPxptujnaQ](https://www.youtube.com/watch?v=JMPxptujnaQ)
+
+## SimpleX Chat: Messaging Meets Perfect Privacy [#](https://simplex.chat/links/#link=simplex-chat-messaging-meets-perfect-privacy)
+
+The Digital Prepper
+
+2024 (est.) English Review
+
+[https://www.youtube.com/watch?v=aKRfDch_WBQ](https://www.youtube.com/watch?v=aKRfDch_WBQ)
+
+## Showdown: Signal, Session, SimpleX, Matrix, XMPP, vs Briar [#](https://simplex.chat/links/#link=showdown-signal-session-simplex-matrix-xmpp-vs-briar)
+
+Simplified Privacy
+
+2024 (est.) English Comparison
+
+This messenger showdown compares Signal, Session, SimpleX, Matrix, XMPP, and Briar, positioning SimpleX as "most likely to grow" due to its corporate APIs. It recommends SimpleX specifically for users who want to hide their communications, while noting it is rated as most vulnerable to psychological phishing among the messengers compared.
+
+[https://simplifiedprivacy.com/messengers/](https://simplifiedprivacy.com/messengers/)
+
+## Every Thing You Need to Know About SimpleX Chat [#](https://simplex.chat/links/#link=every-thing-you-need-to-know-about-simplex-chat)
+
+Libre Self Hosted
+
+2024 (est.) English Guide
+
+This self-hosting directory describes SimpleX as the most private and secure chat platform, using pairwise per-queue identifiers instead of persistent user IDs. It notes the Trail of Bits security audit, AGPL-3.0 licensing, Haskell implementation, and Tor support, emphasizing that SimpleX protocols are and will remain open and in the public domain.
+
+[https://www.libreselfhosted.com/project/simplex-chat/](https://www.libreselfhosted.com/project/simplex-chat/)
+
+## Privacy First Steps [#](https://simplex.chat/links/#link=privacy-first-steps)
+
+Seth For Privacy
+
+2024 (est.) English Guide
+
+In this privacy guide by Seth for Privacy, SimpleX is recommended as a key step in the privacy journey for its protection of both message contents and metadata. The author notes SimpleX has become his preferred messenger over Signal, primarily because it eliminates the phone number requirement, and he references a detailed podcast interview with SimpleX founder Evgeny.
+
+[https://github.com/sethforprivacy/sethforprivacy.com/blob/master/content/posts/privacy-first-steps.md](https://github.com/sethforprivacy/sethforprivacy.com/blob/master/content/posts/privacy-first-steps.md)
+
+## Degoogle Your Private Life: Real-Time Messaging [#](https://simplex.chat/links/#link=degoogle-your-private-life-real-time-messaging)
+
+iode Blog
+
+2024 (est.) English Guide
+
+This iode tech blog article on degoogling covers SimpleX as a decentralized messaging alternative using unidirectional simplex queues. It praises SimpleX's open-source end-to-end encryption and censorship resistance, but identifies significant limitations: a very small user base, no remote contact discovery, slower message delivery, no multi-device support, and total data loss if the device is lost without backups.
+
+[https://blog.iode.tech/degoogle-your-private-life-4-instant-messaging/](https://blog.iode.tech/degoogle-your-private-life-4-instant-messaging/)
+
+## Comparative Review of Protected Messengers [#](https://simplex.chat/links/#link=comparative-review-of-protected-messengers)
+
+Сравнительный обзор защищенных мессенджеров
+
+SecurityLab.ru
+
+2024 (est.) Russian Comparison
+
+This Russian comparative review of protected messengers describes SimpleX as a decentralized platform targeting privacy-conscious users who prioritize anonymity. It notes SimpleX's strengths in avoiding phone numbers and tracking, but identifies fewer features compared to Telegram or Signal, a potentially confusing interface, and a smaller user community as drawbacks.
+
+[https://www.securitylab.ru/blog/personal/SimlpeHacker/354153.php](https://www.securitylab.ru/blog/personal/SimlpeHacker/354153.php)
+
+## SimpleX Chat Overview: What Is It? [#](https://simplex.chat/links/#link=simplex-chat-overview-what-is-it)
+
+Обзор SimpleX Chat: Что это такое?
+
+DDPA.ru
+
+2024 (est.) Russian Review
+
+This Russian overview describes SimpleX as a privacy-focused messenger that assigns users no identifiers of any kind, ensuring complete anonymity. It highlights the hybrid P2P and federated architecture, end-to-end encryption resistant to relay server compromise, and positions SimpleX as ideal for journalists, activists, and cybersecurity enthusiasts.
+
+[https://ddpa.ru/p/simplex-chat](https://ddpa.ru/p/simplex-chat)
+
+## SimpleX: Comparison of Secure Messaging Platforms [#](https://simplex.chat/links/#link=simplex-comparison-of-secure-messaging-platforms)
+
+FutaGuard
+
+2024 Chinese (Tr.) Review
+
+This Chinese comparison of secure messaging platforms gives SimpleX the most favorable assessment, noting it supports message deletion, disappearing messages, channels, and bots. The author calls it "currently the only one with some promise" among privacy-focused alternatives to Telegram, praising its customizable relay servers while noting ongoing cross-device synchronization challenges.
+
+[https://blog.futa.gg/1/simple-x/](https://blog.futa.gg/1/simple-x/)
+
+## Privacy Redefined: First Messenger Without User IDs [#](https://simplex.chat/links/#link=privacy-redefined-first-messenger-without-user-ids)
+
+Prywatnosc zdefiniowana na nowo - Pierwszy komunikator bez identyfikatorow uzytkownikow
+
+CONEA
+
+2024 (est.) Polish Article
+
+[http://conea.pl/aktualnosci/Prywatnosc-zdefiniowana-na-nowo---Pierwszy-komunikator-bez-identyfikator%C3%B3w-uzytkownik%C3%B3w-(ID)_158](http://conea.pl/aktualnosci/Prywatnosc-zdefiniowana-na-nowo---Pierwszy-komunikator-bez-identyfikator%C3%B3w-uzytkownik%C3%B3w-(ID)_158)
+
+## Security in a Box: Communication Tools [#](https://simplex.chat/links/#link=security-in-a-box-communication-tools)
+
+Ilgili Araclar - Communication Tools
+
+Security in a Box / Front Line Defenders
+
+2024 Turkish Guide
+
+This Turkish-language page from Security in a Box, a digital security guide, lists SimpleX Chat as a free, open-source secure messaging application. It notes SimpleX's decentralized network, lack of phone number requirements, absence of fixed user identifiers, end-to-end encryption by default, disappearing messages, and the Trail of Bits security assessment.
+
+[https://securityinabox.org/tr/communication/tools/](https://securityinabox.org/tr/communication/tools/)
+
+## Most Secure Messaging Apps in the World [#](https://simplex.chat/links/#link=most-secure-messaging-apps-in-the-world)
+
+Plaza.ir
+
+2024 Farsi Comparison
+
+[https://www.plaza.ir/241420/best-encrypted-messaging-apps](https://www.plaza.ir/241420/best-encrypted-messaging-apps)
+
+## Truly Secure and Anonymous Social Communication Tools [#](https://simplex.chat/links/#link=truly-secure-and-anonymous-social-communication-tools)
+
+极客小白
+
+2024 Chinese Guide
+
+[https://www.youtube.com/watch?v=UXH6wUOqnfk](https://www.youtube.com/watch?v=UXH6wUOqnfk)
+
+## Top 10 Most Secure Messaging Apps in 2024 [#](https://simplex.chat/links/#link=top-10-most-secure-messaging-apps-in-2024)
+
+Top 10 mest sikre besked-apps i 2024
+
+Moyens I/O Denmark
+
+2024 Danish Comparison
+
+[https://dk.moyens.net/apps/top-mest-sikre-besked-apps-signal-session-simplex/](https://dk.moyens.net/apps/top-mest-sikre-besked-apps-signal-session-simplex/)
+
+## SimpleX Chat: Next-Generation Secure Communication Tool [#](https://simplex.chat/links/#link=simplex-chat-next-generation-secure-communication-tool)
+
+Zhousa.com
+
+2024 Chinese Review
+
+This Chinese article presents SimpleX as a next-generation secure communication tool with an identity-free design requiring no phone number, email, or username. It explains the single-direction message queue architecture with rotating receiver addresses, and positions the platform for ordinary users, journalists, activists, and anyone valuing privacy.
+
+[https://www.zhousa.com/archives/60915.html](https://www.zhousa.com/archives/60915.html)
+
+## SimpleX in Test [#](https://simplex.chat/links/#link=simplex-in-test)
+
+SimpleX im Test
+
+Bitcoinlighthouse.de
+
+2024 German Review
+
+This German review tests SimpleX and explains how it fundamentally differs from other messengers by using no user IDs at all - not even random numbers - to protect metadata privacy. The article describes how SimpleX uses per-contact message queue identifiers instead of user identifiers, and highlights the incognito mode which assigns a different display name for each contact, preventing even contacts from proving they communicate with the same person.
+
+[https://bitcoinlighthouse.de/privacy/simplex-im-test/](https://bitcoinlighthouse.de/privacy/simplex-im-test/)
+
+## Privacy Handbook: SimpleX [#](https://simplex.chat/links/#link=privacy-handbook-simplex)
+
+Datenschutz-Handbuch
+
+Privacy-Handbuch.de
+
+2024 German Guide
+
+This German privacy handbook describes SimpleX as using an innovative metadata-avoidance approach with no account IDs, where encrypted sessions are established directly between clients and servers merely route data packets. It notes SimpleX is particularly suited for concealing contact with specific individuals, though adoption remains limited for everyday use.
+
+[https://www.privacy-handbuch.de/handbuch_89.htm](https://www.privacy-handbuch.de/handbuch_89.htm)
+
+## VC.ru Article on SimpleX [#](https://simplex.chat/links/#link=vcru-article-on-simplex)
+
+VC.ru
+
+2024 Russian Article
+
+This Russian user review describes SimpleX as having clear, high-quality voice and video calls, but identifies significant practical limitations including slow media file delivery, compressed photos, and sluggish video uploads. The author expresses skepticism about Microsoft's involvement with the project and concludes that the messenger functions more like a calling app than a complete communication platform.
+
+[https://vc.ru/id2160811/779184](https://vc.ru/id2160811/779184)
+
+## RuTube: SimpleX Chat Video [#](https://simplex.chat/links/#link=rutube-simplex-chat-video)
+
+RuTube
+
+2024 Russian Review
+
+This is the second video in a Russian-language series about SimpleX Chat, demonstrating its primary functionality including messaging, encrypted voice and video calls, automatic message deletion timers, incognito mode, and database backup capabilities.
+
+[https://rutube.ru/video/b3dcb8869291d7de55596392c05aa24c/](https://rutube.ru/video/b3dcb8869291d7de55596392c05aa24c/)
+
+## SimpleX: Messaging Proof Against the Curious [#](https://simplex.chat/links/#link=simplex-messaging-proof-against-the-curious)
+
+SimpleX: La mensajeria a prueba de curiosos
+
+Francisco Barral
+
+2024 Spanish Article
+
+This Spanish article explains that SimpleX Chat uses no user identifiers and instead generates unique, temporary addresses for each connection. It describes the app's use of end-to-end encryption via the Signal Protocol, peer-to-peer connections where possible, and privacy features including disappearing messages, multiple chat profiles, and incognito mode.
+
+[https://franciscobarral.es/simplex-la-mensajeria-a-prueba-de-curiosos/](https://franciscobarral.es/simplex-la-mensajeria-a-prueba-de-curiosos/)
+
+## SimpleX Chat: Secure Messaging and Decentralized Communities [#](https://simplex.chat/links/#link=simplex-chat-secure-messaging-and-decentralized-communities)
+
+SimpleX Chat: Mensajeria segura y comunidades descentralizadas
+
+El Ecosistema Startup
+
+2024 Spanish Article
+
+This Spanish startup-focused article presents SimpleX as a fully decentralized messaging platform with independent security audits completed in 2022 and 2024. It highlights practical applications for startup founders and community managers who need confidential discussions without depending on centralized platforms, with availability across iOS, Android, macOS, Linux, and Windows.
+
+[https://ecosistemastartup.com/simplex-chat-mensajeria-segura-y-comunidades-descentralizadas/](https://ecosistemastartup.com/simplex-chat-mensajeria-segura-y-comunidades-descentralizadas/)
+
+## Secure Messaging Apps: Complete Technical Analysis [#](https://simplex.chat/links/#link=secure-messaging-apps-complete-technical-analysis)
+
+Apps de Mensajeria Seguras: Analisis Tecnico Completo
+
+EsGeeks
+
+2024 Spanish Comparison
+
+This Spanish technical analysis describes SimpleX's approach to radical metadata reduction through ephemeral addresses and message queues specific to each contact, preventing reconstruction of social graphs. It rates SimpleX as suitable for users with strict privacy models and advanced technical knowledge, noting that while IP addresses remain visible to relay servers, using Tor resolves this.
+
+[https://esgeeks.com/app-mensajeria-mas-segura/](https://esgeeks.com/app-mensajeria-mas-segura/)
+
+## Most Secure Decentralized Messengers [#](https://simplex.chat/links/#link=most-secure-decentralized-messengers)
+
+Mensajeros descentralizados mas seguros
+
+EsGeeks
+
+2024 Spanish Comparison
+
+This Spanish article on secure decentralized messengers categorizes SimpleX Chat as focusing on minimalism and maximum security, with a high level of anonymity and absence of metadata. It notes SimpleX suffers from limited functionality and low popularity compared to other messaging platforms.
+
+[https://esgeeks.com/mensajeros-descentralizados-mas-seguros/](https://esgeeks.com/mensajeros-descentralizados-mas-seguros/)
+
+## Telegram Privacy Alternatives [#](https://simplex.chat/links/#link=telegram-privacy-alternatives)
+
+Conoce las alternativas a Telegram de mensajeria encriptada y segura
+
+CriptoNoticias
+
+2024 Spanish Article
+
+This Spanish crypto news article presents SimpleX Chat as a privacy-focused alternative to Telegram, noting that developers believe persistent alphanumeric identifiers compromise privacy. It highlights SimpleX's use of temporary anonymous message queue identifiers and single-use QR codes that reduce traceability.
+
+[https://www.criptonoticias.com/tecnologia/alternativas-telegram-privacidad-mensajeria/](https://www.criptonoticias.com/tecnologia/alternativas-telegram-privacidad-mensajeria/)
+
+## SimpleX Chat Tutorial [#](https://simplex.chat/links/#link=simplex-chat-tutorial-spanish)
+
+Bitcoin.ar
+
+2024 Spanish Guide
+
+This tutorial from ONG Bitcoin Argentina presents SimpleX as "the first mailbox without user identification," launched in 2021. It notes that while SimpleX includes standard messaging features, its ergonomics remain less fluid than WhatsApp or Signal and can be more restrictive when adding contacts, positioning it as suitable for privacy-conscious users willing to sacrifice daily convenience.
+
+[https://bitcoin.ar/tutoriales/simplex-chat/](https://bitcoin.ar/tutoriales/simplex-chat/)
+
+## Top Most Secure Messaging Apps: Signal, Session, SimpleX [#](https://simplex.chat/links/#link=top-most-secure-messaging-apps-signal-session-simplex)
+
+Top aplicativos de mensagens mais seguros
+
+Moyens I/O Portugal
+
+2024 Portuguese Comparison
+
+[https://pt.moyens.net/aplicativos/top-aplicativos-mensagens-mais-seguros-signal-session-simplex/](https://pt.moyens.net/aplicativos/top-aplicativos-mensagens-mais-seguros-signal-session-simplex/)
+
+## SimpleX: How to Use the World's Most Private Messaging App [#](https://simplex.chat/links/#link=simplex-how-to-use-the-worlds-most-private-messaging-app)
+
+Simplex: como usar o app de mensagens mais privado do mundo
+
+Soberano News
+
+2024 Portuguese Guide
+
+This Portuguese guide describes SimpleX as designed to not know who you are, with whom you speak, or when you speak, using blind relay servers that operate as message forwarders without identifying senders or recipients. It acknowledges the app may be slower and have a less polished design than competitors, making it ideal for journalists, activists, and those concerned with digital surveillance.
+
+[https://soberano.news/guias-e-ferramentas/simplex-como-usar-o-app-de-mensagens-mais-privado-do-mundo/](https://soberano.news/guias-e-ferramentas/simplex-como-usar-o-app-de-mensagens-mais-privado-do-mundo/)
+
+## How to Install SimpleX Chat Messenger on Linux via Flatpak [#](https://simplex.chat/links/#link=how-to-install-simplex-chat-messenger-on-linux-via-flatpak)
+
+Como instalar o mensageiro Simplex Chat no Linux via Flatpak
+
+Edivaldo Brito
+
+2024 Portuguese Guide
+
+This Portuguese tutorial explains how to install SimpleX Chat on Linux via Flatpak, describing it as a private, open-source encrypted messenger with no user IDs. It lists SimpleX's features including end-to-end encrypted messages, files, images, audio/video calls, secret group chats, instant private notifications, and portable chat profiles, while emphasizing that SimpleX uses no phone numbers or other user identifiers and stores all data on client devices.
+
+[https://www.edivaldobrito.com.br/como-instalar-o-mensageiro-simplex-chat-no-linux-via-flatpak/](https://www.edivaldobrito.com.br/como-instalar-o-mensageiro-simplex-chat-no-linux-via-flatpak/)
+
+## Top 10 Best Messaging Apps for Secure, Anonymous and Privacy-Respecting Chat [#](https://simplex.chat/links/#link=top-10-best-messaging-apps-for-secure-anonymous-and-privacy-respecting-chat)
+
+Le 10 migliori app di messaggistica per chat sicure, anonime e rispettose della privacy
+
+Jacopo Coccia
+
+2024 Italian Comparison
+
+This Italian article lists the 10 best messaging apps for secure and anonymous chats, mentioning apps like Threema, Signal, and Wire that offer end-to-end encryption and zero-log policies. SimpleX Chat is not specifically named in the available excerpt, which focuses on the general landscape of privacy-focused messaging and the growing need for data protection.
+
+[https://www.jacopococcia.com/10-migliori-app-messaggistica-per-chat-sicure-anonime-privacy/](https://www.jacopococcia.com/10-migliori-app-messaggistica-per-chat-sicure-anonime-privacy/)
+
+## What Is SimpleX Chat? [#](https://simplex.chat/links/#link=what-is-simplex-chat-english-1)
+
+No Trust Verify
+
+2024 English Article
+
+This article from the NoTrustVerify blog describes SimpleX as the first messaging platform that doesn't require any login, using the SimpleX Messaging Protocol (SMP) with one-way message queues. It highlights features like incognito mode with random names per contact and live message typing visibility, while acknowledging that multi-device synchronization and large group management still need improvement.
+
+[https://blog.notrustverify.ch/what-is-simplex-chat](https://blog.notrustverify.ch/what-is-simplex-chat)
+
+## Interview With the Author of SimpleX Chat: The Most Secure Messaging by Design [#](https://simplex.chat/links/#link=interview-with-the-author-of-simplex-chat-the-most-secure-messaging-by-english)
+
+GatoOscuro
+
+2024 English Interview
+
+This interview with SimpleX founder Evgeny Poberezkin covers the protocol's design beginning in 2020 and mobile app launch in March 2022. Poberezkin acknowledges the "100% private" claim is aspirational marketing rather than absolute truth, and explains that the fully open-source, decentralized architecture prevents government backdoors from compromising the entire network.
+
+[https://gatooscuro.xyz/interview-with-the-author-of-simplex-chat-the-most-secure-messaging-by-design/](https://gatooscuro.xyz/interview-with-the-author-of-simplex-chat-the-most-secure-messaging-by-design/)
+
+## SimpleX: Best Private Messenger? [#](https://simplex.chat/links/#link=simplex-best-private-messenger)
+
+Tom Spark's Reviews
+
+2024 English Review
+
+[https://www.youtube.com/watch?v=PbYm1G-QVUc](https://www.youtube.com/watch?v=PbYm1G-QVUc)
+
+## SimpleX Chat Tutorial [#](https://simplex.chat/links/#link=simplex-chat-tutorial-english)
+
+How to use apps?
+
+2024 English Guide
+
+[https://www.youtube.com/watch?v=X7CJlbBJNcc](https://www.youtube.com/watch?v=X7CJlbBJNcc)
+
+## SimpleX Chat Review [#](https://simplex.chat/links/#link=simplex-chat-review-english-1)
+
+QuickLearn
+
+2024 English Review
+
+[https://www.youtube.com/watch?v=cGGrRnXAh1w](https://www.youtube.com/watch?v=cGGrRnXAh1w)
+
+## SimpleX Chat: Settings and Usage Guide [#](https://simplex.chat/links/#link=simplex-chat-settings-and-usage-guide)
+
+匿名メッセージアプリ - Simple X Chat の設定と使い方
+
+ひとりかくれんぼ / note.com
+
+2024 Japanese Guide
+
+This Japanese article covers SimpleX Chat's settings and usage, including configuration of global chat settings for complete message deletion, disabling link previews, activating SimpleX Lock with a passcode, and enabling self-destruct mode. The author recommends using a VPN alongside SimpleX for genuine anonymity and stresses that message deletion requires mutual consent between users.
+
+[https://note.com/deeplife/n/n84b9e0a75ac5](https://note.com/deeplife/n/n84b9e0a75ac5)
+
+## How to Bypass SimpleX Chat Blocking [#](https://simplex.chat/links/#link=how-to-bypass-simplex-chat-blocking)
+
+dept.one
+
+2024 Japanese Article
+
+This Japanese article explains that SimpleX Chat was blocked in Russia in September 2024 due to its confidentiality and security features, and provides three methods to bypass the block: using a developer-provided proxy, a third-party SOCKS proxy, or a local proxy app like Orbot. It describes SimpleX as a highly secure messenger with no user identification, decentralized architecture, and scrambled message ordering to prevent timing attacks.
+
+[https://dept.one/memo/simplex-chat/](https://dept.one/memo/simplex-chat/)
+
+## SimpleX Chat on IQ.wiki [#](https://simplex.chat/links/#link=simplex-chat-on-iqwiki)
+
+IQ.wiki
+
+2024 English Review
+
+This IQ.wiki page provides a comprehensive overview of SimpleX Chat, covering its custom protocols (SimpleXMQ and SMP), end-to-end encryption with the Signal Double Ratchet algorithm, and post-quantum resistant encryption via CRYSTALS-Kyber. It notes key milestones including the v1 mobile release in 2022, Jack Dorsey's investment in August 2024, and planned Community Vouchers utility token system for 2026.
+
+[https://iq.wiki/wiki/simplex-chat](https://iq.wiki/wiki/simplex-chat)
+
+## SimpleX: How to Use the Most Private Messaging App [#](https://simplex.chat/links/#link=simplex-how-to-use-the-most-private-messaging-app)
+
+SimpleX: how to use the world's most private messaging app
+
+Soberano News
+
+2024 English Guide
+
+This English guide explains SimpleX's approach of deleting metadata rather than just encrypting messages, using servers as blind relays with temporary one-way queues where servers cannot identify senders or recipients. It acknowledges the app can be slower and have a less polished interface than competitors, positioning it for journalists, activists, and those concerned about digital surveillance.
+
+[https://soberano.news/en/guides-and-tools/simplex-how-to-use-the-worlds-most-private-messaging-app/](https://soberano.news/en/guides-and-tools/simplex-how-to-use-the-worlds-most-private-messaging-app/)
+
+## Libertarian Institute Article on SimpleX [#](https://simplex.chat/links/#link=libertarian-institute-article-on-simplex)
+
+Institute for Libertarian Ideas / Japan
+
+2024 English Article
+
+This Libertarian Institute article emphasizes that SimpleX serves everyday citizens rather than just activists, providing significant privacy improvements with minimal sacrifice of convenience. It highlights identity flexibility where users can change display names per contact, hidden profiles behind password protection, and notes SimpleX functions as an anonymization network similar to Tor.
+
+[https://institute-for-libertarian.org/the-libertarian/2148/](https://institute-for-libertarian.org/the-libertarian/2148/)
+
+## Better and More Secure Messenger Than Signal [#](https://simplex.chat/links/#link=better-and-more-secure-messenger-than-signal)
+
+Lepszy i bezpieczniejszy komunikator niz Signal
+
+Selfhosty.pl
+
+2024 Polish Comparison
+
+This Polish article argues there are more secure messengers than Signal, noting that Signal's requirement for a phone number is a serious privacy weakness since phone numbers and IP addresses can be used to track users. The article recommends exploring alternatives that do not require a phone number for registration, positioning them as safer choices for users concerned about government surveillance and data breaches.
+
+[https://selfhosty.pl/lepszy-i-bezpieczniejszy-komunikator-niz-signal/](https://selfhosty.pl/lepszy-i-bezpieczniejszy-komunikator-niz-signal/)
+
+## Anonymous Messaging Apps: Recommended List [#](https://simplex.chat/links/#link=anonymous-messaging-apps-recommended-list)
+
+Ni ming tong xin huan jing gou jian - messeji apuri osusume ichiran
+
+ひとりかくれんぼ / note.com
+
+2024 (est.) Japanese Review
+
+This Japanese article strongly recommends SimpleX Chat as the top choice for anonymous secure communication, emphasizing that it requires no phone number or email and doesn't use user identifiers or collect metadata. The author notes that user experience is mostly acceptable with only minor delays in call connections, and observes that SimpleX adoption remains relatively low in Japan.
+
+[https://note.com/deeplife/n/ne7ffdd8a50cd](https://note.com/deeplife/n/ne7ffdd8a50cd)
+
+## Building Your First Anonymous Digital Life: Fundamentals [#](https://simplex.chat/links/#link=building-your-first-anonymous-digital-life-fundamentals)
+
+Tokumei de ikiru tame no saisho no kankyo kochiku to kihon no hanashi
+
+ひとりかくれんぼ / note.com
+
+2024 (est.) Japanese Guide
+
+This Japanese article about building an anonymous digital life uses SimpleX Chat as the recommended contact method for readers seeking personalized guidance on privacy topics. It presents SimpleX solely as a secure, end-to-end encrypted communication channel without elaborating on its specific features.
+
+[https://note.com/deeplife/n/nea6f1c4e08a7](https://note.com/deeplife/n/nea6f1c4e08a7)
+
+## SimpleX on Yggdrasil Network [#](https://simplex.chat/links/#link=simplex-on-yggdrasil-network)
+
+Yggdrasil Wiki
+
+2024 (est.) Russian Guide
+
+This Russian wiki page describes SimpleX as the only messenger that uses no user profile identifiers, not even random numbers, with fully open-source client and server code that anyone can self-host. It explains that SimpleX delivers messages using per-contact message queue identifiers rather than user IDs, with plans to automate queue rotation so that even conversations will have no long-term network-visible identifiers.
+
+[https://yggwiki.cc/social_media:simplex](https://yggwiki.cc/social_media:simplex)
+
+## SimpleX Chat Review [#](https://simplex.chat/links/#link=simplex-chat-review-german)
+
+Tests & Tips
+
+2024 (est.) German Review
+
+German review and testing site covering SimpleX Chat. Evaluates the messenger's privacy features, usability, and security properties as part of a broader mobile app testing catalog.
+
+[https://tests.tips/en/?software/mobile-apps/simplex](https://tests.tips/en/?software/mobile-apps/simplex)
+
+## Protocols Not Platforms: NOSTR, BTC, SimpleX [#](https://simplex.chat/links/#link=protocols-not-platforms-nostr-btc-simplex)
+
+Closed Network Privacy Podcast
+
+2024 (est.) English Podcast
+
+[https://closednetwork.io/podcast/episode-38-protocols-not-platforms-nostr-btc-simplex/](https://closednetwork.io/podcast/episode-38-protocols-not-platforms-nostr-btc-simplex/)
+
+## RoboSats Orderbook Alert Bot for SimpleX Chat [#](https://simplex.chat/links/#link=robosats-orderbook-alert-bot-for-simplex-chat)
+
+TempleOfSats
+
+2024 (est.) English Service
+
+This open-source bot monitors the RoboSats peer-to-peer Bitcoin trading platform and sends alerts via SimpleX Chat when orders matching user-defined criteria (currency, premium rates, payment methods, trade amounts) are posted. Users manage alerts through simple commands, with a default 7-day alert lifetime and extension capabilities.
+
+[https://github.com/TempleOfSats/Robosats-Orderbook-Alert-Bot-for-SimpleX-Chat](https://github.com/TempleOfSats/Robosats-Orderbook-Alert-Bot-for-SimpleX-Chat)
+
+## SimpleX Chat on LunarDAO Wiki [#](https://simplex.chat/links/#link=simplex-chat-on-lunardao-wiki)
+
+LunarDAO
+
+2024 (est.) English Community
+
+This LunarDAO wiki page presents SimpleX as a privacy-focused federated messaging platform that requires no phone number or account creation, using one-way message queues instead of traditional accounts. It describes features including live typing indicators, voice/video calls, disappearing messages, self-destruct passcodes, and SOCKS proxy routing, while acknowledging challenges with multi-device synchronization and large group management.
+
+[https://wiki.lunardao.net/simplexchat.html](https://wiki.lunardao.net/simplexchat.html)
+
+## Tech Guides for Anarchists: End-to-End Encrypted Messaging [#](https://simplex.chat/links/#link=tech-guides-for-anarchists-end-to-end-encrypted-messaging)
+
+AnarSec
+
+2024 (est.) English Guide
+
+This anarchist security guide notes SimpleX Chat uses decentralized servers (not peer-to-peer) with in-memory storage and no phone number requirement. It recommends Cwtch over SimpleX for text-only communication but suggests SimpleX as an acceptable option for voice and video calls, noting that content padding exists to frustrate correlation attacks via message size.
+
+[https://www.anarsec.guide/posts/e2ee/](https://www.anarsec.guide/posts/e2ee/)
+
+## Hack Liberty: Cypherpunk Community on SimpleX [#](https://simplex.chat/links/#link=hack-liberty-cypherpunk-community-on-simplex)
+
+Hack Liberty
+
+2024 (est.) English Community
+
+[https://links.hackliberty.org/](https://links.hackliberty.org/)
+
+## Nowhere.moe: Privacy Hosting with SimpleX Infrastructure [#](https://simplex.chat/links/#link=nowheremoe-privacy-hosting-with-simplex-infrastructure)
+
+Nowhere.moe
+
+2024 (est.) English Service
+
+Privacy-focused hosting service operates community SimpleX SMP and XFTP relay servers with both clearnet and Tor onion addresses. Runs anonymous SimpleX chatrooms and provides tutorials on privacy and self-hosting.
+
+[https://nowhere.moe/](https://nowhere.moe/)
+
+## XMRBazaar: Monero Marketplace on SimpleX [#](https://simplex.chat/links/#link=xmrbazaar-monero-marketplace-on-simplex)
+
+XMRBazaar
+
+2024 (est.) English Service
+
+This Monero community post announces an unofficial XMRBazaar group on SimpleX Chat, providing two join links - one described as "possibly slower but uncensorable" using direct server protocols and another via the SimpleX Directory Service described as "faster but censorable." The group migrated from Matrix to SimpleX for discussing the Monero marketplace.
+
+[https://monero.town/post/4623536](https://monero.town/post/4623536)
+
+## Simplified Privacy: Tech Groups on SimpleX [#](https://simplex.chat/links/#link=simplified-privacy-tech-groups-on-simplex)
+
+Simplified Privacy
+
+2024 (est.) English Community
+
+Simplified Privacy lists several active SimpleX Chat groups covering privacy, security, cryptocurrency (Monero and Bitcoin/Lightning Network), Nostr protocol, and a Switzerland-based privacy community. The page positions SimpleX alongside Session and XMPP as decentralized messaging platforms for privacy-conscious technical discussions.
+
+[https://simplifiedprivacy.com/techgroups/](https://simplifiedprivacy.com/techgroups/)
+
+## SimpleX Server Docker Installation Guide (SMP/XFTP) [#](https://simplex.chat/links/#link=simplex-server-docker-installation-guide-smpxftp)
+
+Hack Liberty
+
+2024 (est.) English Guide
+
+This Hack Liberty forum guide provides detailed instructions for deploying SimpleX Chat's SMP and XFTP servers using Docker Compose, with dual-network configuration for both clearnet and Tor operation. It covers port configuration, security measures including running containers as unprivileged users, and emphasizes backing up private CA keys before deletion from the server.
+
+[https://forum.hackliberty.org/t/simplex-server-docker-installation-guide-smp-xftp/140](https://forum.hackliberty.org/t/simplex-server-docker-installation-guide-smp-xftp/140)
+
+## SimpleX VS Quiet: Privacy and Security [#](https://simplex.chat/links/#link=simplex-vs-quiet-privacy-and-security)
+
+Hack Forums
+
+2024 (est.) English Comparison
+
+[https://hackforums.net/blog/SimpleX-VS-Quiet](https://hackforums.net/blog/SimpleX-VS-Quiet)
+
+## MoneroKon 2024: SimpleX Chat talk [#](https://simplex.chat/links/#link=monerokon-2024-simplex-chat-talk)
+
+SimpleX Chat
+
+2024 English Conference talk
+
+MoneroKon 2024 conference talk by Evgeny Poberezkin on how SimpleX Chat bridges the gap between privacy-focused and mass-market messaging applications.
+
+[https://www.youtube.com/watch?v=Fl-QS0-qENw](https://www.youtube.com/watch?v=Fl-QS0-qENw)
+
+## SimpleXChat on Monero + Price and More! [#](https://simplex.chat/links/#link=simplexchat-on-monero-price-and-more)
+
+Monero Talk
+
+2024 (est.) English Interview
+
+Monero Talk episode 239 featuring a discussion of SimpleX Chat's integration with Monero, payment incentives for server operators, and the broader privacy messaging landscape.
+
+[https://www.youtube.com/live/quk4WY3fJCc?si=IQ0rutoHQpWtF2Un&t=3812](https://www.youtube.com/live/quk4WY3fJCc?si=IQ0rutoHQpWtF2Un&t=3812)
+
+## SimpleX Chat: Simple Messaging With Unusually Good Privacy [#](https://simplex.chat/links/#link=simplex-chat-simple-messaging-with-unusually-good-privacy-english)
+
+Remember Lads Subscribe to Big Bear
+
+Dec 19, 2023 English Review
+
+[https://www.youtube.com/watch?v=zkEY9m2E-Y4](https://www.youtube.com/watch?v=zkEY9m2E-Y4)
+
+## SimpleX Chat Part 2 [#](https://simplex.chat/links/#link=simplex-chat-part-2)
+
+Blog de Joselito
+
+Dec 7, 2023 Spanish Review
+
+In this follow-up Spanish post, the author details SimpleX's technical strengths including metadata protection through unidirectional message queues, double-layer encryption, and automatic message deletion from servers after receipt. While primarily an XMPP user, the author calls SimpleX "an excellent messaging platform" and appreciates that robust security works automatically without user effort.
+
+[https://joselito.mataroa.blog/blog/simplex-chat-parte-2/](https://joselito.mataroa.blog/blog/simplex-chat-parte-2/)
+
+## SimpleX Chat [#](https://simplex.chat/links/#link=simplex-chat-spanish)
+
+Blog de Joselito
+
+Dec 5, 2023 Spanish Comparison
+
+This Spanish blog post acknowledges SimpleX offers superior privacy features over XMPP, including metadata protection and automatic encryption, but argues XMPP is not obsolete. The author identifies a vulnerability in SimpleX's group key distribution relying on administrators, and views SimpleX as promising but unproven long-term, using both platforms with XMPP as his primary messenger.
+
+[https://joselito.mataroa.blog/blog/simplex-chat/](https://joselito.mataroa.blog/blog/simplex-chat/)
+
+## SimpleX Chat v5.4: Link Mobile and Desktop Apps via Quantum-Resistant Protocol [#](https://simplex.chat/links/#link=simplex-chat-v54-link-mobile-and-desktop-apps-via-quantum-resistant-protocol)
+
+NoBs Bitcoin
+
+Nov 2023 English News
+
+No BS Bitcoin covers SimpleX Chat v5.4, which introduced the ability to link mobile and desktop apps via a secure quantum-resistant protocol on local networks. The update also improved group functionality with faster joining, incognito profile support for groups, and added screen sharing for video calls on desktop.
+
+[https://www.nobsbitcoin.com/simplex-chat-v5-4/](https://www.nobsbitcoin.com/simplex-chat-v5-4/)
+
+## Session and SimpleX: Encrypted Messenger Comparison [#](https://simplex.chat/links/#link=session-and-simplex-encrypted-messenger-comparison-english)
+
+FreedomNode
+
+Oct 29, 2023 English Comparison
+
+FreedomNode compares SimpleX and Session, noting that SimpleX takes privacy further by eliminating user identifiers entirely and using temporary anonymous message queue identifiers for each conversation. The article notes SimpleX represents a more experimental privacy frontier while Session provides greater stability and cross-device compatibility, with SimpleX having limitations around desktop support and requiring both parties to be online to establish connections.
+
+[https://freedomnode.com/blog/session-and-simplex-encrypted-messenger-comparison/](https://freedomnode.com/blog/session-and-simplex-encrypted-messenger-comparison/)
+
+## In Search of a Secure Messenger [#](https://simplex.chat/links/#link=in-search-of-a-secure-messenger)
+
+U poshukakh bezpechnoho mesendzhera
+
+KR. Labs Research
+
+Oct 24, 2023 Ukrainian Guide
+
+This Ukrainian guide to secure messaging describes SimpleX as a decentralized P2P messenger where users own their own servers, requiring no phone numbers or usernames for registration. It highlights end-to-end encryption by default with no metadata collection, positioning SimpleX as an advanced privacy solution appealing to activists and journalists.
+
+[https://research.kr-labs.com.ua/secure-and-privacy-messaging-apps-guide/](https://research.kr-labs.com.ua/secure-and-privacy-messaging-apps-guide/)
+
+## SimpleX Is a Revolutionary Messaging Platform That Redefines Privacy [#](https://simplex.chat/links/#link=simplex-is-a-revolutionary-messaging-platform-that-redefines-privacy)
+
+O SimpleXchat e uma plataforma de mensagens revolucionarias que redefinem a privacidade
+
+Alex Emidio
+
+Oct 10, 2023 Portuguese Review
+
+This Portuguese-language Medium article describes SimpleX Chat as a revolutionary privacy platform that eliminates user IDs entirely, requiring no phone numbers or email addresses. It highlights end-to-end encrypted messages, group chats, file sharing, disappearing messages, and encrypted audio/video calls, all operating on decentralized servers using unidirectional message queues.
+
+[https://medium.com/@alexemidio/o-simplexchat-%C3%A9-uma-plataforma-de-mensagens-revolucion%C3%A1rias-que-redefinem-a-privacidade-sendo-o-4690f2a1b2d4](https://medium.com/@alexemidio/o-simplexchat-%C3%A9-uma-plataforma-de-mensagens-revolucion%C3%A1rias-que-redefinem-a-privacidade-sendo-o-4690f2a1b2d4)
+
+## New Service: SimpleX Chat Server [#](https://simplex.chat/links/#link=new-service-simplex-chat-server)
+
+AdminForge
+
+Oct 4, 2023 German Service
+
+AdminForge, a German community infrastructure provider, announces hosting a new SimpleX Chat server at simplex.adminforge.de. It describes SimpleX's Double-Ratchet encryption, multiple profile support, anonymous group participation, and explains that SMP servers function only as relays holding messages until recipients reconnect while XFTP file transfer servers retain uploads temporarily.
+
+[https://adminforge.de/tools/neuer-service-simplex-chat-server/](https://adminforge.de/tools/neuer-service-simplex-chat-server/)
+
+## Session and SimpleX: Encrypted Messenger Comparison [#](https://simplex.chat/links/#link=session-and-simplex-encrypted-messenger-comparison-english-1)
+
+Michal Kodnar
+
+Oct 2023 English Comparison
+
+This comparison characterizes SimpleX as the first identifier-free messenger, using temporary anonymous paired message queues instead of user IDs. The author finds both Session and SimpleX are interesting projects but notes SimpleX remains buggy and incomplete, requiring QR codes for new connections and lacking disappearing messages at the time of writing.
+
+[https://michalkodnar.xyz/blog-en/culture-en/session-and-simlex-encrypted-messenger-comparison/](https://michalkodnar.xyz/blog-en/culture-en/session-and-simlex-encrypted-messenger-comparison/)
+
+## SimpleX Chat Review [#](https://simplex.chat/links/#link=simplex-chat-review-english)
+
+Freedom.Tech
+
+Sep 26, 2023 English Review
+
+Freedom.tech's review praises SimpleX Chat's beautiful UI, metadata protection through its peer-to-relay architecture, double ratchet encryption, and incognito mode for pseudonymous communication. The review identifies key weaknesses including intermittent notifications on both iOS and Android and flaky audio/video calls in beta, but concludes it is a fantastic tool ideal for activists, journalists, and privacy-focused users.
+
+[https://freedom.tech/simplex-chat-review/](https://freedom.tech/simplex-chat-review/)
+
+## Messaging Applications on Medium [#](https://simplex.chat/links/#link=messaging-applications-on-medium)
+
+Mesajlasma Uygulamalari
+
+Gizli Kalsin / Medium
+
+Sep 3, 2023 Turkish Article
+
+This Turkish Medium article lists SimpleX Chat as one of six recommended secure messaging applications, describing it as a decentralized instant messaging app that operates without phone numbers or user IDs. It notes users join conversations by scanning QR codes or clicking invite links, and the application provides complete anonymity.
+
+[https://medium.com/@gizlikalsin/mesajla%C5%9Fma-uygulamalar%C4%B1-74dc81d78737](https://medium.com/@gizlikalsin/mesajla%C5%9Fma-uygulamalar%C4%B1-74dc81d78737)
+
+## SimpleX Chat v5.3: Desktop App, Local File Encryption and Improved Groups [#](https://simplex.chat/links/#link=simplex-chat-v53-desktop-app-local-file-encryption-and-improved-groups)
+
+NoBs Bitcoin
+
+Sep 2023 English News
+
+No BS Bitcoin reports on SimpleX Chat v5.3, which introduced a new desktop app, a directory service with group improvements, and encrypted local files and media with forward secrecy. The release also achieved a 40% reduction in memory usage and added new privacy controls for message visibility.
+
+[https://www.nobsbitcoin.com/simplex-chat-v5-3/](https://www.nobsbitcoin.com/simplex-chat-v5-3/)
+
+## SimpleX Chat: Anonymous Messenger Without ID [#](https://simplex.chat/links/#link=simplex-chat-anonymous-messenger-without-id)
+
+SimpleX CHAT - анонимный мессенджер без ID
+
+Чёрный Треугольник
+
+Aug 25, 2023 Russian Review
+
+[https://www.youtube.com/watch?v=Ecx5jGUn-hQ](https://www.youtube.com/watch?v=Ecx5jGUn-hQ)
+
+## SimpleX Chat Review [#](https://simplex.chat/links/#link=simplex-chat-review-russian)
+
+te-st.org
+
+Aug 21, 2023 Russian Review
+
+This review by Russian digital rights organization Te-st characterizes SimpleX Chat as one of the first messengers where the list of missing security features is notably short. It emphasizes that the absence of UserID means users cannot be identified afterward, and unlike most secure messaging apps, no phone number is required.
+
+[https://te-st.org/2023/08/21/simplex-chat-review/](https://te-st.org/2023/08/21/simplex-chat-review/)
+
+## SimpleX Chat Is a Revolution in Encrypted Communication [#](https://simplex.chat/links/#link=simplex-chat-is-a-revolution-in-encrypted-communication-czech)
+
+SimpleX Chat je revoluci v sifrovane komunikaci
+
+Kryptoanarchista.cz
+
+Aug 17, 2023 Czech Review
+
+This Czech crypto-anarchist publication calls SimpleX a revolution in encrypted communication that surpasses Signal and Threema. It praises the temporary anonymous pairwise identifiers that prevent correlation attacks, and the phone-number-free setup via QR codes, while noting limitations in desktop availability and the need for an alternative channel to initiate contact.
+
+[https://kryptoanarchista.cz/simplex-chat-je-revoluci-v-sifrovane-komunikaci/](https://kryptoanarchista.cz/simplex-chat-je-revoluci-v-sifrovane-komunikaci/)
+
+## SimpleX Chat Is a Revolution in Encrypted Communication [#](https://simplex.chat/links/#link=simplex-chat-is-a-revolution-in-encrypted-communication-english)
+
+Kryptoanarchista.cz
+
+Aug 17, 2023 English Review
+
+This Czech crypto-anarchist blog presents SimpleX as an open-source encrypted messenger requiring no KYC, supporting text, voice, video calls, file sharing, and Tor connectivity. It notes the absence of persistent identities prevents tracking of user connections but acknowledges current limitations including the need for QR code exchange to start conversations and lack of cross-device synchronization.
+
+[https://kryptoanarchista.cz/en/simplex-chat-is-a-revolution-in-encrypted-communication/](https://kryptoanarchista.cz/en/simplex-chat-is-a-revolution-in-encrypted-communication/)
+
+## SimpleX Chat: Overview of Main Functions [#](https://simplex.chat/links/#link=simplex-chat-overview-of-main-functions)
+
+SimpleX Chat #2: обзор основных функций
+
+Теплица социальных технологий
+
+Aug 10, 2023 Russian Review
+
+[https://www.youtube.com/watch?v=fp1QUPNkxKI](https://www.youtube.com/watch?v=fp1QUPNkxKI)
+
+## SimpleX Chat: Messenger Without UserID With Maximum Protection [#](https://simplex.chat/links/#link=simplex-chat-messenger-without-userid-with-maximum-protection)
+
+SimpleX Chat: мессенджер без UserID с максимальной защитой переписки
+
+Теплица социальных технологий
+
+Aug 8, 2023 Russian Review
+
+[https://www.youtube.com/watch?v=g9HGLNCkEyk](https://www.youtube.com/watch?v=g9HGLNCkEyk)
+
+## SimpleX Chat - Simple Messaging With Unusually Good Privacy [#](https://simplex.chat/links/#link=simplex-chat-simple-messaging-with-unusually-good-privacy-english-1)
+
+Bornhack 2023 conference, Chaos Computer Club
+
+Aug 07, 2023 English Conference talk
+
+This is a spontaneous talk about the relatively new (mobile apps released 2022) open source SimpleX Chat instant messenger protocol and software, and some reasons why it's a far better choice than in particular Matrix.
+
+[https://media.ccc.de/v/bornhack2023-56143-simplex-chat-simple-m](https://media.ccc.de/v/bornhack2023-56143-simplex-chat-simple-m)
+
+## SimpleX Chat Messaging App [#](https://simplex.chat/links/#link=simplex-chat-messaging-app)
+
+App de mensajeria SimpleX Chat
+
+Alt43.es
+
+Aug 1, 2023 Spanish Review
+
+This Spanish-language Medium article reviews SimpleX Chat's security features including end-to-end encryption, open-source code, and the ability to register without a phone number or email. It explains that users exchange temporary anonymous identifiers via QR codes or one-time links, with all data stored only on client devices using an encrypted, portable database format.
+
+[https://medium.com/@burp.es/app-de-mensajer%C3%ADa-simplex-chat-c0ad46b50f1f](https://medium.com/@burp.es/app-de-mensajer%C3%ADa-simplex-chat-c0ad46b50f1f)
+
+## We Found the Most Incognito iPhone Messaging App [#](https://simplex.chat/links/#link=we-found-the-most-incognito-iphone-messaging-app)
+
+On a trouve l'app de messagerie iPhone la plus incognito
+
+iPhon.fr
+
+Jul 15, 2023 French Article
+
+This French iPhone blog highlights SimpleX Chat as the most confidential messaging application on iOS, featuring no user identification requirements, encrypted metadata and profile hiding, and decentralized infrastructure allowing users to run it on personal servers. Contacts are established via unique QR codes rather than phone numbers or usernames.
+
+[https://www.iphon.fr/post/on-a-trouve-lapp-de-messagerie-iphone-la-plus-incognito](https://www.iphon.fr/post/on-a-trouve-lapp-de-messagerie-iphone-la-plus-incognito)
+
+## SimpleX: Secure Messaging With Self-Hosted Server [#](https://simplex.chat/links/#link=simplex-secure-messaging-with-self-hosted-server)
+
+Simplex - Messagerie securisee avec serveur auto-heberge
+
+Paf LeGeek
+
+Jun 19, 2023 French Guide
+
+[https://www.youtube.com/watch?v=66URjJ1RkeM](https://www.youtube.com/watch?v=66URjJ1RkeM)
+
+## What Is SimpleX Chat? [#](https://simplex.chat/links/#link=what-is-simplex-chat-english)
+
+No Trust Verify / Medium
+
+Jun 2023 English Article
+
+NoTrustVerify describes SimpleX Chat as the first messaging platform that requires no login and respects privacy by default, operating through a decentralized architecture using one-way message queues rather than centralized servers. The article discusses incognito mode, live message typing indicators, and separate chat profiles, while noting challenges around multi-device synchronization and large group management.
+
+[https://medium.com/notrustverify/what-is-simplex-chat-11124d39a318](https://medium.com/notrustverify/what-is-simplex-chat-11124d39a318)
+
+## SimpleX Chat: Another Kusaimara Article [#](https://simplex.chat/links/#link=simplex-chat-another-kusaimara-article)
+
+Kusaimara
+
+Jun 2023 Japanese Article
+
+This Japanese blog post announces that SimpleX Chat added Japanese language support in version 5.1 released in late May 2023. It notes SimpleX doesn't assign unique user IDs and supports Tor network communication, while acknowledging that account portability requires database passphrase export rather than simple login across devices.
+
+[https://kusaimara.net/2023/06/444](https://kusaimara.net/2023/06/444)
+
+## Safer Than Signal or Telegram? SimpleX Offers Absolute Privacy Without Creating a Personal ID [#](https://simplex.chat/links/#link=safer-than-signal-or-telegram-simplex-offers-absolute-privacy-without-creating-a)
+
+Bezpecnejsi nez Signal nebo Telegram? SimpleX nabidne absolutni soukromi bez vytvareni osobniho ID
+
+Cnews.cz
+
+May 27, 2023 Czech News
+
+This Czech tech news article presents SimpleX as safer than Signal or Telegram, highlighting its elimination of permanent user IDs in favor of temporary anonymous message identifiers deleted immediately after sending. It notes the project originated in 2020 and gained attention when Jack Dorsey endorsed it as potentially more secure than Signal or Telegram.
+
+[https://www.cnews.cz/bezpecnejsi-nez-signal-nebo-telegram-simplex-nabidne-absolutni-soukromi-bez-nutnosti-vytvareni-osobniho-id/](https://www.cnews.cz/bezpecnejsi-nez-signal-nebo-telegram-simplex-nabidne-absolutni-soukromi-bez-nutnosti-vytvareni-osobniho-id/)
+
+## SimpleX Chat: The Messaging App [#](https://simplex.chat/links/#link=simplex-chat-the-messaging-app)
+
+SimpleX Chat: la app de mensajeria segura sin identificadores de usuario
+
+Computekni
+
+May 2023 Spanish Review
+
+This Spanish article describes SimpleX Chat as the first messaging platform without user identifiers of any kind, using end-to-end encryption and QR codes for private connections. It highlights the app's availability on iOS, Android, and F-Droid, and notes its open-source codebase allows public inspection and quick resolution of security issues.
+
+[https://www.computekni.com/2023/05/simplex-chat-la-app-de-mensajeria.html](https://www.computekni.com/2023/05/simplex-chat-la-app-de-mensajeria.html)
+
+## SimpleX Chat and How Privacy Aligns With the Future of Computing [#](https://simplex.chat/links/#link=simplex-chat-and-how-privacy-aligns-with-the-future-of-computing)
+
+Opt Out Podcast
+
+Feb 27, 2023 English Podcast
+
+This Opt Out Podcast episode features SimpleX Chat founder Evgeny discussing how privacy aligns with the future of computing. The conversation covers data sovereignty, SimpleX's decentralized architecture, and the project's emphasis on user control, with resources provided on running independent servers.
+
+[https://optoutpod.com/episodes/s3e02-simplexchat/](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Classification of Secure Messengers: New Projects [#](https://simplex.chat/links/#link=classification-of-secure-messengers-new-projects)
+
+Klassifikatsiya zashchishchyonnykh messendzherov. Novyye proyekty
+
+Habr / GlobalSign
+
+Feb 27, 2023 Russian News
+
+This Habr article classifies SimpleX Chat as an experimental, "extremely privacy-focused" messenger for enthusiasts, describing it as the first messenger without user IDs of any kind. It identifies SimpleX as one of only two messengers (alongside Briar) that meets all security criteria on the author's evaluation scale.
+
+[https://habr.com/ru/companies/globalsign/articles/719330/](https://habr.com/ru/companies/globalsign/articles/719330/)
+
+## SimpleX Chat: A Star on the Open-Source Messenger Horizon [#](https://simplex.chat/links/#link=simplex-chat-a-star-on-the-open-source-messenger-horizon)
+
+SimpleX Chat - Frohlockender Stern am Open-Source Messenger Himmel
+
+hackspoiler.de
+
+2023 (est.) German Review
+
+This German security blog highlights SimpleX Chat as a privacy-focused open-source messenger requiring no user ID, with end-to-end encryption for all communications including voice messages, audio/video calls, and self-destructing messages. The article positions it as a secure alternative to proprietary platforms, comparing it to Signal and Session under the AGPL V3 license.
+
+[https://hackspoiler.de/simplex-chat-verschluesselter-opensource-messenger/](https://hackspoiler.de/simplex-chat-verschluesselter-opensource-messenger/)
+
+## Good Messengers Instead of WhatsApp [#](https://simplex.chat/links/#link=good-messengers-instead-of-whatsapp)
+
+Gute Messenger statt WhatsApp
+
+Digitalcourage
+
+2023 (est.) German Guide
+
+German digital rights organization Digitalcourage describes SimpleX as a relatively new open-source messenger launched in 2022 that uses distributed servers with temporary connection identifiers rather than phone numbers or usernames. While it functions reliably and supports voice messages, file transfers, and video calls, the organization only conditionally recommends it due to its youth as a project and limited track record.
+
+[https://digitalcourage.de/digitale-selbstverteidigung/messenger](https://digitalcourage.de/digitale-selbstverteidigung/messenger)
+
+## SimpleX Chat v5.2: Message Delivery Receipts [#](https://simplex.chat/links/#link=simplex-chat-v52-message-delivery-receipts)
+
+NoBs Bitcoin
+
+2023 English News
+
+This release announcement covers SimpleX Chat v5.2.0, highlighting new message delivery receipts with per-contact opt-out, conversation filtering by favorites and unread status, and group improvements including full context for replied messages. The developers emphasized their commitment to keeping SimpleX protocols open and in the public domain.
+
+[https://www.nobsbitcoin.com/simplex-chat-v5-2-0/](https://www.nobsbitcoin.com/simplex-chat-v5-2-0/)
+
+## SimpleX Server Now Available for StartOS [#](https://simplex.chat/links/#link=simplex-server-now-available-for-startos)
+
+NoBs Bitcoin
+
+2023 English News
+
+This article announces SimpleX Server availability on StartOS through the Start9 Registry. It explains SimpleX's server architecture where servers act as simple relays that do not store profiles, contacts, or groups, and each conversation typically uses two different servers - one chosen by each participant - with Tor server support built in.
+
+[https://www.nobsbitcoin.com/simplex-server-now-available-for-startos/](https://www.nobsbitcoin.com/simplex-server-now-available-for-startos/)
+
+## New Super-Secure Messenger SimpleX Chat: Advantages and Disadvantages [#](https://simplex.chat/links/#link=new-super-secure-messenger-simplex-chat-advantages-and-disadvantages)
+
+Novyi super-zakhyshchenyi mesendzhder SimpleX Chat: perevahy y nedoliky
+
+Kostiantyn Korsun / Censor.net
+
+2023 Ukrainian Review
+
+This Ukrainian blog post reviews SimpleX Chat's advantages and disadvantages, noting it requires no phone number, email, or any user identifier - a feature rare among messengers. The author highlights that SimpleX stores all data locally with no cloud storage, supports one-time profile links, an incognito mode with random display names per contact, and invitation-only group chats, while also being fundamentally different from Signal, WhatsApp, Threema, Wire, and Session which all rely on some form of user ID.
+
+[https://censor.net/ua/blogs/3525466/novyyi-super-zahyschenyyi-mesendjer-simplex-chat-perevagy-yi-nedoliky](https://censor.net/ua/blogs/3525466/novyyi-super-zahyschenyyi-mesendjer-simplex-chat-perevagy-yi-nedoliky)
+
+## SimpleX Chat Server Now Available for StartOS [#](https://simplex.chat/links/#link=simplex-chat-server-now-available-for-startos)
+
+Start9
+
+2023 (est.) English Service
+
+This Stacker News post announces SimpleX Chat server availability for StartOS (Start9's operating system), describing its support for direct messages, group messages, calls, and video calls with end-to-end encryption. Commenters praise it as "very promising tech" that is "plug and play right at the initial download" and comfortable to recommend to non-technical friends.
+
+[https://stacker.news/items/196092](https://stacker.news/items/196092)
+
+## Anonymous Messaging Apps [#](https://simplex.chat/links/#link=anonymous-messaging-apps)
+
+App di messaggistica anonime
+
+Le Alternative
+
+Dec 14, 2022 Italian Guide
+
+This Italian blog about alternative apps describes SimpleX Chat as an open-source, end-to-end encrypted messenger that has received an independent security audit. It emphasizes that the only way to add a contact is through QR code or link, requiring neither phone number nor email address, and notes availability on F-Droid, Play Store, and iOS.
+
+[https://blog.lealternative.net/2022/12/14/app-di-messaggistica-anonime/](https://blog.lealternative.net/2022/12/14/app-di-messaggistica-anonime/)
+
+## SimpleX: Impressions From the Messenger Without Identifiers [#](https://simplex.chat/links/#link=simplex-impressions-from-the-messenger-without-identifiers)
+
+SimpleX: Eindrucke vom Messenger ohne Identifier
+
+Kuketz IT-Security Blog
+
+Dec 2, 2022 German Review
+
+German privacy blogger Mike Kuketz rates SimpleX as "conditionally recommended," praising its innovative no-identifier design and Tor support. He identifies weaknesses including the absence of contact verification, high battery consumption, and client instability, though notes the developer indicated these issues are being addressed.
+
+[https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/)
+
+## SimpleX: The First Messenger Without User Identifiers [#](https://simplex.chat/links/#link=simplex-the-first-messenger-without-user-identifiers)
+
+SimpleX - первый мессенджер без идентификаторов пользователей
+
+Habr / Privacy Accelerator
+
+Dec 2022 Russian Article
+
+This Russian-language Habr article introduces SimpleX Chat as a privacy-focused messenger that operates without user identifiers, using separate message queue identifiers for each contact. It highlights the SimpleX Messaging Protocol with end-to-end encryption, Tor routing support, open-source code, and a professional security audit by Trail of Bits.
+
+[https://habr.com/ru/companies/privacyaccelerator/articles/705778/](https://habr.com/ru/companies/privacyaccelerator/articles/705778/)
+
+## Open-Source Messenger SimpleX: Anonymous and Now Also Private Chatting [#](https://simplex.chat/links/#link=open-source-messenger-simplex-anonymous-and-now-also-private-chatting)
+
+Open-Source-Messenger SimpleX: Anonym und jetzt auch privat chatten
+
+Heise Online
+
+Nov 29, 2022 German News
+
+Heise reports on SimpleX Chat version 4.0 introducing private server authentication through password protection, allowing server operators to control who can receive messages while maintaining the platform's anonymous design. Previously all chat servers were public, but administrators can now restrict access by sharing passwords with intended users.
+
+[https://www.heise.de/news/Open-Source-Messenger-SimpleX-anonym-und-jetzt-auch-privat-chatten-7359889.html](https://www.heise.de/news/Open-Source-Messenger-SimpleX-anonym-und-jetzt-auch-privat-chatten-7359889.html)
+
+## SimpleX's Revolutionary Idea [#](https://simplex.chat/links/#link=simplexs-revolutionary-idea)
+
+SimpleXの革命的なアイデアに心を打たれた
+
+vpn53049 / Ameblo
+
+Sep 5, 2022 Japanese Article
+
+This Japanese blog post explains SimpleX's key innovation: generating unique IDs per conversation rather than using persistent anonymous IDs. The author argues this eliminates the social graph exposure risk inherent in competing apps and solves the practical frustration of managing multiple devices or accounts to maintain anonymity across different social contexts.
+
+[https://ameblo.jp/vpn53049/entry-12786598980.html](https://ameblo.jp/vpn53049/entry-12786598980.html)
+
+## Privacy-Focused Chat Tool SimpleX: First Impressions [#](https://simplex.chat/links/#link=privacy-focused-chat-tool-simplex-first-impressions)
+
+プライバシー特化のチャットツール「SimpleX」を利用してみる
+
+Kusaimara Blog
+
+Sep 2022 Japanese Review
+
+This Japanese blog post from September 2022 shares first impressions of SimpleX as a privacy-focused chat tool available on mobile. The author finds it usable despite being in development and expresses cautious optimism, noting SimpleX later gained Japanese language support by June 2023.
+
+[https://kusaimara.net/2022/09/20](https://kusaimara.net/2022/09/20)
+
+## This Is How This Secure Messaging App Works Without User Identifiers [#](https://simplex.chat/links/#link=this-is-how-this-secure-messaging-app-works-without-user-identifiers)
+
+Asi funciona esta app de mensajeria segura que carece de identificadores para los usuarios
+
+WWWhatsnew
+
+Aug 13, 2022 Spanish News
+
+This Spanish tech news site explains that SimpleX Chat delivers messages without using sender or recipient identifiers, relying on the SimpleX Messaging Protocol (SMP) with persistent queues. It describes how users generate unique invitation codes for each contact, with messages stored directly on devices rather than centralized servers.
+
+[https://wwwhatsnew.com/2022/08/13/asi-funciona-esta-app-de-mensajeria-segura-que-carece-de-identificadores-para-los-usuarios/](https://wwwhatsnew.com/2022/08/13/asi-funciona-esta-app-de-mensajeria-segura-que-carece-de-identificadores-para-los-usuarios/)
+
+## SimpleX Chat Wants to Offer Complete Privacy [#](https://simplex.chat/links/#link=simplex-chat-wants-to-offer-complete-privacy)
+
+SimpleX Chat will vollstandige Privatsphare bieten
+
+iphone-ticker.de
+
+Jul 13, 2022 German News
+
+German iPhone blog iphone-ticker covers SimpleX Chat's privacy approach of establishing direct connections through shared QR codes or links for end-to-end encrypted messaging. The article highlights version 3.0's push notifications that reveal nothing about chat content or contacts, and the addition of encrypted audio and video calling.
+
+[https://www.iphone-ticker.de/simplex-chat-will-vollstaendige-privatsphaere-bieten-194389/](https://www.iphone-ticker.de/simplex-chat-will-vollstaendige-privatsphaere-bieten-194389/)
+
+## So Apple Won't Read Along: SimpleX Chat Updated to Version 3 [#](https://simplex.chat/links/#link=so-apple-wont-read-along-simplex-chat-updated-to-version-3)
+
+Damit Apple nichts mitliest: SimpleX-Chat aktualisiert auf Version 3
+
+Heise Online
+
+Jul 12, 2022 German News
+
+Heise covers SimpleX Chat version 3's privacy-focused iOS push notifications that contain no information about contacts or chat content, preventing any data from reaching Apple's servers. The update also introduced database export/import functionality and faster message transmission while maintaining backward compatibility.
+
+[https://www.heise.de/news/Damit-Apple-nichts-mitliest-SimpleX-Chat-aktualisiert-auf-Version-3-7170288.html](https://www.heise.de/news/Damit-Apple-nichts-mitliest-SimpleX-Chat-aktualisiert-auf-Version-3-7170288.html)
+
+## SimpleX.Chat Is a Chat Network That Preserves Metadata Privacy [#](https://simplex.chat/links/#link=simplexchat-is-a-chat-network-that-preserves-metadata-privacy)
+
+SimpleX.Chat e chat mrezha, koyato zapazva poveritelnostta na metadannite
+
+Hristo Hristov / Medium
+
+Jun 5, 2022 Bulgarian Article
+
+This Bulgarian Medium article explains SimpleX as a decentralized client-server network that routes messages through disposable nodes while maintaining sender and receiver anonymity. It details the dual end-to-end encryption layers, DNS independence, and the absence of any global user identities, noting that network connections can only be discovered through observation of IP packet timing.
+
+[https://hristo-hristov.medium.com/simplex-chat-%D0%B5-%D1%87%D0%B0%D1%82-%D0%BC%D1%80%D0%B5%D0%B6%D0%B0-%D0%BA%D0%BE%D1%8F%D1%82%D0%BE-%D0%B7%D0%B0%D0%BF%D0%B0%D0%B7%D0%B2%D0%B0-%D0%BF%D0%BE%D0%B2%D0%B5%D1%80%D0%B8%D1%82%D0%B5%D0%BB%D0%BD%D0%BE%D1%81%D1%82%D1%82%D0%B0-%D0%BD%D0%B0-%D0%BC%D0%B5%D1%82%D0%B0%D0%B4%D0%B0%D0%BD%D0%BD%D0%B8%D1%82%D0%B5-eb31243435a6](https://hristo-hristov.medium.com/simplex-chat-%D0%B5-%D1%87%D0%B0%D1%82-%D0%BC%D1%80%D0%B5%D0%B6%D0%B0-%D0%BA%D0%BE%D1%8F%D1%82%D0%BE-%D0%B7%D0%B0%D0%BF%D0%B0%D0%B7%D0%B2%D0%B0-%D0%BF%D0%BE%D0%B2%D0%B5%D1%80%D0%B8%D1%82%D0%B5%D0%BB%D0%BD%D0%BE%D1%81%D1%82%D1%82%D0%B0-%D0%BD%D0%B0-%D0%BC%D0%B5%D1%82%D0%B0%D0%B4%D0%B0%D0%BD%D0%BD%D0%B8%D1%82%D0%B5-eb31243435a6)
+
+## Pavol Luptak on Censorship, Security, and Nomadism [#](https://simplex.chat/links/#link=pavol-luptak-on-censorship-security-and-nomadism)
+
+SP21 Pavol Luptak o cenzure, bezpecnosti, nomadstvi
+
+Stackuj.cz Podcast
+
+May 22, 2022 Czech Podcast
+
+[https://www.youtube.com/watch?v=N0prtSOyeUU](https://www.youtube.com/watch?v=N0prtSOyeUU)
+
+## Haskell in Production: SimpleX [#](https://simplex.chat/links/#link=haskell-in-production-simplex)
+
+Serokell
+
+May 17, 2022 English Interview
+
+Serokell interviews SimpleX Chat creator Evgeny Poberezkin about building the platform in Haskell, chosen for its strength in highly concurrent communication applications with features like green threads and transactional memory. The article discusses challenges of compiling Haskell to mobile devices and the project's exploration of monetization through optional subscriptions while remaining fully open-source.
+
+[https://serokell.io/blog/haskell-in-production-simplex](https://serokell.io/blog/haskell-in-production-simplex)
+
+## SimpleX Chat: An Open and Secure Chat [#](https://simplex.chat/links/#link=simplex-chat-an-open-and-secure-chat)
+
+SimpleX Chat, en oppen och saker chatt
+
+Oppet Moln
+
+May 12, 2022 Swedish Article
+
+This Swedish article introduces SimpleX as an open and secure chat that requires no global identity such as phone number, username, or IP address. It claims superior security compared to Signal, XMPP/Matrix, and other P2P protocols, while acknowledging that users must evaluate the security claims themselves and that usability tradeoffs exist.
+
+[https://oppetmoln.se/20220512/simplex-chat-en-oppen-och-saker-chatt/](https://oppetmoln.se/20220512/simplex-chat-en-oppen-och-saker-chatt/)
+
+## Encrypted Messengers: Comparison [#](https://simplex.chat/links/#link=encrypted-messengers-comparison)
+
+Encrypted messengers - comparison
+
+Juraj Bednar
+
+May 3, 2022 English Comparison
+
+This encrypted messenger comparison describes SimpleX as the youngest app in the review, using asymmetric connections through QR codes or URLs that make it difficult to correlate sending and receiving patterns. The reviewer notes the interface shows signs of ongoing development and some reliability issues, and suggests SimpleX suits users prioritizing anonymity for temporary rather than permanent communications.
+
+[https://juraj.bednar.io/en/blog-en/2022/05/03/encrypted-messengers-comparison/](https://juraj.bednar.io/en/blog-en/2022/05/03/encrypted-messengers-comparison/)
+
+## Overview and Comparison of Encrypted Communication Tools [#](https://simplex.chat/links/#link=overview-and-comparison-of-encrypted-communication-tools)
+
+Prehlad a porovnanie sifrovanych komunikacnych nastrojov - messengerov
+
+Juraj Bednar
+
+Apr 5, 2022 Slovak Comparison
+
+In this Slovak overview of encrypted communication tools, Juraj Bednar describes SimpleX as the youngest application in the comparison, using asymmetric connections via QR codes with no user identifiers. He notes basic functionality including audio and video calls works, but advises waiting before using it for family or business communication due to ongoing development and some technical issues.
+
+[https://juraj.bednar.io/blog/2022/04/05/sifrovane-komunikacne-nastroje-prehlad/](https://juraj.bednar.io/blog/2022/04/05/sifrovane-komunikacne-nastroje-prehlad/)
+
+## SimpleX Chat Now Also for Smartphones [#](https://simplex.chat/links/#link=simplex-chat-now-also-for-smartphones)
+
+SimpleX-Chat jetzt auch fur Smartphones
+
+GNU/Linux.ch
+
+Mar 10, 2022 German News
+
+This Swiss GNU/Linux community site reports on SimpleX Chat's release of smartphone applications for iPhone and Android, expanding beyond its command-line interface. The article emphasizes end-to-end encryption, decentralized architecture, and QR code-based peer-to-peer connections without routing data through SimpleX servers.
+
+[https://gnulinux.ch/simplex-chat-smartphones](https://gnulinux.ch/simplex-chat-smartphones)
+
+## Decentralized, Anonymous, Encrypted: SimpleX Messenger Now Also for Smartphones [#](https://simplex.chat/links/#link=decentralized-anonymous-encrypted-simplex-messenger-now-also-for-smartphones)
+
+Dezentral, anonym, verschlusselt: SimpleX-Messenger jetzt auch furs Smartphone
+
+Heise Online
+
+Mar 9, 2022 German News
+
+Heise reports on SimpleX Chat releasing smartphone apps for iPhone and Android after initially being available only as a command-line application. The article highlights the decentralized architecture where servers cannot know who communicated with whom, with users sharing QR codes to establish encrypted connections.
+
+[https://www.heise.de/news/Dezentral-anonym-verschluesselt-SimpleX-Messenger-jetzt-auch-fuers-Smartphone-6544488.html](https://www.heise.de/news/Dezentral-anonym-verschluesselt-SimpleX-Messenger-jetzt-auch-fuers-Smartphone-6544488.html)
+
+## SimpleX 1.0.0: Decentralized, Privacy-Respecting and Encrypted Chat [#](https://simplex.chat/links/#link=simplex-100-decentralized-privacy-respecting-and-encrypted-chat-german)
+
+SimpleX 1.0.0: Dezentraler, Privatsphare achtender und verschlusselter Chat
+
+Heise Online
+
+Jan 13, 2022 German News
+
+Heise covers SimpleX Chat reaching version 1.0.0, marking its protocol as stable with guaranteed compatibility for future releases. The article explains the dual-layer end-to-end encryption using a double-ratchet mechanism that changes keys for each message, with decentralized servers routing messages without storing user data or metadata.
+
+[https://www.heise.de/news/SimpleX-1-0-0-Dezentraler-Privatsphaere-achtender-und-verschluesselter-Chat-6325990.html](https://www.heise.de/news/SimpleX-1-0-0-Dezentraler-Privatsphaere-achtender-und-verschluesselter-Chat-6325990.html)
+
+## SimpleX 1.0.0: Decentralized, Privacy-Respecting and Encrypted Chat [#](https://simplex.chat/links/#link=simplex-100-decentralized-privacy-respecting-and-encrypted-chat-german-1)
+
+SimpleX 1.0.0: Dezentraler, Privatsphaere achtender und verschluesselter Chat
+
+Tarnkappe.info
+
+Jan 13, 2022 German Community
+
+This German security forum post announces SimpleX's stable 1.0.0 release, describing its two-layer end-to-end encryption with double-ratchet algorithm and unidirectional simplex queues with unique encryption keys per queue. It emphasizes that establishing secure channels requires exchanging encryption keys through QR codes or invitations, and notes the terminal client's availability plus a DigitalOcean one-click server deployment option.
+
+[https://tarnkappe.info/forum/t/simplex-1-0-0-dezentraler-privatsphaere-achtender-und-verschluesselter-chat/9812](https://tarnkappe.info/forum/t/simplex-1-0-0-dezentraler-privatsphaere-achtender-und-verschluesselter-chat/9812)
+
+## SimpleX Chat: The Messaging App Every Privacy Enthusiast Should Use [#](https://simplex.chat/links/#link=simplex-chat-the-messaging-app-every-privacy-enthusiast-should-use)
+
+SimpleX Chat la aplicacion de mensajeria que todo entusiasta de la privacidad deberia utilizar
+
+GatoOscuro
+
+2022 (est.) Spanish Review
+
+This Spanish-language article recommends SimpleX Chat as an exceptional privacy platform that eliminates metadata surveillance risks present in alternatives like Signal. The author highlights out-of-band key exchange making man-in-the-middle attacks practically impossible, anonymous peer identifiers, self-destructing messages, and a decentralized client-centric architecture.
+
+[https://gatooscuro.xyz/simplex-chat-la-aplicacion-de-mensajeria-que-todo-entusiasta-de-la-privacidad-deberia-utilizar/](https://gatooscuro.xyz/simplex-chat-la-aplicacion-de-mensajeria-que-todo-entusiasta-de-la-privacidad-deberia-utilizar/)
+
+## Messenger SimpleX Protects Privacy and Is Open Source [#](https://simplex.chat/links/#link=messenger-simplex-protects-privacy-and-is-open-source)
+
+Messenger SimpleX schutzt Privatsphare und ist Open Source
+
+Linux-Magazin
+
+2022 (est.) German News
+
+German Linux Magazin reports on SimpleX as an anonymous, encrypted open-source messenger (AGPLv3) that uses no central server to track connections - servers only relay messages, and anyone can self-host a message broker using SimpleXMQ. The article highlights SimpleX's double ratchet end-to-end encryption with forward secrecy and metadata concealment, noting that at the time of writing only a command-line client was available with mobile apps in development.
+
+[https://www.linux-magazin.de/news/messenger-simplex-schuetzt-privatsphaere-und-ist-open-source/](https://www.linux-magazin.de/news/messenger-simplex-schuetzt-privatsphaere-und-ist-open-source/)
+
+## German Language Pack for Mobile Privacy Messaging Service SimpleX [#](https://simplex.chat/links/#link=german-language-pack-for-mobile-privacy-messaging-service-simplex)
+
+Jetzt auch auf Deutsch anonym chatten: Update fuer Messenger SimpleX
+
+Heise Online
+
+2022 German News
+
+Heise, a major German tech publication, reports on SimpleX version 4.0 adding a German language pack. The update also introduced encryption of received and stored messages using SQLCipher, a TypeScript SDK for chatbot integration, and self-hosted WebRTC ICE server support. The article notes the founder was seeking donations for a $20,000 independent security audit.
+
+[https://www.heise.de/news/Deutsches-Sprachpaket-fuer-den-mobilen-Privatsphaere-Nachrichtendienst-SimpleX-7278902.html](https://www.heise.de/news/Deutsches-Sprachpaket-fuer-den-mobilen-Privatsphaere-Nachrichtendienst-SimpleX-7278902.html)
+
+## SimpleX Chat Overview [#](https://simplex.chat/links/#link=simplex-chat-overview)
+
+GNU/Linux.ch
+
+2022 German Article
+
+This GNU/Linux-focused Swiss German article explains SimpleX's architecture as a decentralized network using one-way nodes for asynchronous message forwarding, avoiding any form of identity for message routing. It details two layers of end-to-end encryption with forward secrecy, and notes that servers do not retain user records, do not communicate with each other, and have no way to obtain a complete list of participating servers.
+
+[https://gnulinux.ch/simplex-chat](https://gnulinux.ch/simplex-chat)
+
+## SimpleX [#](https://simplex.chat/links/#link=simplex-german)
+
+freie-messenger.de
+
+updated regularly German Article
+
+This German free messenger comparison site provides a comprehensive overview of SimpleX Chat, noting its distinctive lack of user identifiers and end-to-end encryption with data stored only on client devices. The assessment concludes that while SimpleX is an innovative privacy-focused messenger suitable for individuals and activists, it has limitations for business use and lacks interoperability with standard protocols like XMPP.
+
+[https://www.freie-messenger.de/simplex/](https://www.freie-messenger.de/simplex/)
+
+## The Best Private Instant Messengers [#](https://simplex.chat/links/#link=the-best-private-instant-messengers)
+
+Privacy Guides
+
+updated regularly English Review
+
+Privacy Guides recommends SimpleX Chat as an instant messenger that does not depend on any unique identifiers such as phone numbers or usernames. The page notes its double ratchet encryption with quantum resistance, metadata protection through unidirectional message delivery queues, and independent security audits conducted in July 2024 and October 2022.
+
+[https://www.privacyguides.org/en/real-time-communication/](https://www.privacyguides.org/en/real-time-communication/)
+
+## SimpleX [#](https://simplex.chat/links/#link=simplex-english)
+
+Whonix Wiki
+
+updated regularly English Review
+
+The Whonix wiki describes SimpleX as a general-purpose instant messaging client with both client and server released as Freedom Software under GNU AGPLv3. It highlights mandatory end-to-end encryption, quantum-resistant encryption by default for one-on-one chats, and incognito mode, while providing detailed Flatpak installation instructions and warning that users must export their chat database before shutdown to avoid losing all data.
+
+[https://www.whonix.org/wiki/SimpleX](https://www.whonix.org/wiki/SimpleX)
+
+## Private Messaging: Wikilibriste Recommendations [#](https://simplex.chat/links/#link=private-messaging-wikilibriste-recommendations)
+
+Les messageries privees
+
+Wikilibriste
+
+updated regularly French Review
+
+This French privacy guide recommends SimpleX for users seeking a strict, intentionally confidential messaging model. It highlights SimpleX's unique reception addresses per contact, Double Ratchet encryption, incognito mode, and the absence of user identifiers, while noting that user IP remains visible to relay servers unless Tor is used.
+
+[https://www.wikilibriste.fr/messagerie-vie-privee/](https://www.wikilibriste.fr/messagerie-vie-privee/)
+
+## Messenger Matrix [#](https://simplex.chat/links/#link=messenger-matrix)
+
+Kuketz IT-Security Blog
+
+updated regularly German Comparison
+
+This comprehensive German messenger comparison table rates SimpleX on dozens of technical criteria. It notes SimpleX's decentralized architecture, post-quantum encryption, NaCl/Signal Protocol cryptography, and Trail of Bits security audit, but gives it a "very limited" recommendation and categorizes it as targeting advanced users rather than beginners.
+
+[https://www.messenger-matrix.de/messenger-matrix.html](https://www.messenger-matrix.de/messenger-matrix.html)
diff --git a/links/index.html b/links/index.html
index da7c63b2d4..4965d30f94 100644
--- a/links/index.html
+++ b/links/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/links.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -7654,17 +7658,7 @@ window.addEventListener('click',(e)=>{
         <div id="links-pagination"></div>
     </div>
 </section>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-decentralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Decentralized network</h4><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="decentralized-network">Read more</button></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-double-ratchet-algorithm" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Double ratchet algorithm</h4><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="double-ratchet-algorithm">Read more</button></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-onion-routing" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Onion routing</h4><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="onion-routing">Read more</button></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-cryptography" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum cryptography</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-cryptography">Read more</button></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-user-identity" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">User identity</h4><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-decentralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Decentralized network</h4><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="decentralized-network">Read more</button></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-double-ratchet-algorithm" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Double ratchet algorithm</h4><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="double-ratchet-algorithm">Read more</button></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-onion-routing" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Onion routing</h4><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="onion-routing">Read more</button></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-peer-to-peer" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Peer-to-peer</h4><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="peer-to-peer">Read more</button></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-cryptography" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum cryptography</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-cryptography">Read more</button></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-user-identity" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">User identity</h4><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/livestream.md b/livestream.md
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+# SimpleX Chat: Foundation For the Future
+
+Livestream and Q&A about SimpleX Chat roadmap and crowdfunding
+
+Recorded on September 15, 2026
+
+Watch [on X](https://x.com/i/broadcasts/1pKdRDneNyoJW) or [YouTube](https://www.youtube.com/watch?v=vIwgi39VMFA)
+
+[Get a stake in SimpleX Chat](https://simplex.chat/crowdfunding/)
diff --git a/livestream/index.html b/livestream/index.html
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     <meta property="og:image" content="https://simplex.chat/img/livestream/share-livestream.jpg"/>
     <meta name="twitter:card" content="summary_large_image"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/livestream.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/section-4-desktop.webp" as="image" type="image/webp" media="(min-width: 960px)">
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+# SimpleX: full text of the core pages
+
+The core pages of simplex.chat in one file. The index of all pages is at https://simplex.chat/llms.txt.
+
+---
+
+Source: https://simplex.chat/docs/why.md
+
+# Why we are building SimpleX Network
+
+You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that your power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
+
+---
+
+Source: https://simplex.chat/llms/facts.md
+
+# SimpleX: key facts
+
+Facts about SimpleX network and SimpleX Chat, each with the date it was stated and its source. Updated 2026-10-08. Machine-readable version: [simplex.chat/llms/facts.json](https://simplex.chat/llms/facts.json).
+
+## Network and users
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| User identifiers on the network | None – no phone numbers, usernames, account IDs or random user IDs | 2026 | [How SimpleX works](https://simplex.chat/docs/simplex.md) |
+| Monthly active users | 600,000+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| User growth | about 70% in the last six months | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| App downloads | 3 million+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Messages per day via preset servers | 20 million+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Paid marketing | none before the equity crowdfunding campaign | until August 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Independent publications about SimpleX | 200+ reviews, posts and videos in 20+ languages | October 2026 | [Links](https://simplex.chat/links.md) |
+
+## Network participants
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Servers run by volunteers | about 1,000 | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Preset server operators | SimpleX Chat and Flux | since December 2024 | [Blog](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md) |
+| Public channels created | 12,500+ in the five months since scalable channels shipped | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Curated directory | 500+ public groups and channels, 30% active daily | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md), [Directory](https://simplex.chat/directory.md) |
+| Businesses supporting customers over SimpleX | 50+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| GitHub | 19,000+ stars, 1,400+ forks | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md), [GitHub](https://github.com/simplex-chat/simplex-chat) |
+
+## Security
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| End-to-end encryption | double ratchet with post-quantum key exchange (sntrup761) on every ratchet step, on by default in direct conversations | since v5.7, April 2024 | [Blog](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md) |
+| IP address protection | private message routing: 2-hop routing where the sender chooses the forwarding relay and the recipient chooses the destination relay, so neither side observes the other's IP address | since v5.8, June 2024 | [Blog](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) |
+| Implementation security assessment | Trail of Bits | October 2022 | [Blog](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md), [Report](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf) |
+| Cryptographic design review | Trail of Bits | July 2024 | [Blog](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md), [Report](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf) |
+| Third Trail of Bits audit | completed, to be published | 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Licence | AGPL-3.0 | 2026 | [LICENSE](https://github.com/simplex-chat/simplex-chat/blob/stable/LICENSE) |
+
+## Company and funding
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Founder | Evgeny Poberezkin, creator of the Ajv JSON Schema validator | 2026 | [Ajv](https://github.com/ajv-validator/ajv) |
+| Total investment to date | $1.7M | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| User donations | $650,000+, including from Vitalik Buterin | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Prior investors | Village Global and angel investors (pre-seed, closed in July 2022); Jack Dorsey and Asymmetric Capital Partners (closed in July 2023) | announced April 2023 and August 2024 | [Blog](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) |
+| Equity crowdfunding | on Wefunder, launched 20 August 2026 | October 2026 | [Blog](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md), [Crowdfunding](https://simplex.chat/crowdfunding.md) |
+| Governance | SimpleX Network Consortium: an agreement between the non-profit SimpleX Network Foundation and SimpleX Chat | 2026 | [Blog](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md) |
+| Business model | free private messaging; channels and businesses pay for public names, business messaging and servers for big channels | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+
+## Public names
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Test names (.testing) | available since v7-beta | July 2026 | [Blog](https://simplex.chat/blog/20260722-simplex-public-names.md) |
+| .simplex names sale | starts 12 December 2026, 18:00 UTC | October 2026 | [simplex.domains](https://simplex.domains/) |
+| Registry | SimpleX Name Service, a fork of ENS on Ethereum, without off-chain indexer or metadata services | July 2026 | [Whitepaper](https://simplex.chat/docs/protocol/names-overview.md) |
+
+
+---
+
+Source: https://simplex.chat/llms/answers.md
+
+# SimpleX: answers to common questions
+
+Short answers with links to the full documentation. Numbers are in [key facts](https://simplex.chat/llms/facts.md).
+
+## What is SimpleX, in one sentence?
+
+SimpleX is the first messaging network without user identifiers of any kind – no phone numbers, usernames or random IDs – so nobody, including its servers, can see who talks to whom.
+
+## What is the difference between SimpleX network and SimpleX Chat?
+
+SimpleX network is the open protocol and the servers that relay messages. SimpleX Chat is the free, open-source app (iOS, Android, Linux, macOS, Windows and a terminal client) that uses the network, and also the company that builds both.
+
+## How does SimpleX deliver messages without user identifiers?
+
+Each conversation uses its own pair of one-way message queues, one for each direction, usually on different servers. A queue has a random address that is used only for that conversation. Contacts and groups are stored only on users' devices. To connect, people share a one-time link or a QR code, which also carries the keys for end-to-end encryption, so servers cannot substitute them. Details: [How SimpleX works](https://simplex.chat/docs/simplex.md), [protocol overview](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/overview-tjr.md).
+
+## What can servers and network observers see?
+
+Servers relay end-to-end encrypted messages and delete them once they are delivered. A server sees the random addresses of the queues it hosts and the times when messages arrive and are received. All messages are padded to the same size. With private message routing, the sender chooses the forwarding server and the recipient chooses the destination server, so neither side can observe the other's IP address. A server cannot see who talks to whom, cannot read messages, and cannot add or change them undetectably. Details: [security model](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/security.md).
+
+## How strong is the encryption?
+
+Messages are end-to-end encrypted with a double ratchet that gives forward secrecy and recovery after a key compromise. A post-quantum key exchange (sntrup761) is added on every ratchet step and is on by default in direct conversations. An additional encryption layer between servers and devices prevents correlating sent and received traffic. Details: [post-quantum double ratchet](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/pqdr.md).
+
+## Why are public channels not end-to-end encrypted?
+
+By design. No system can provide encrypted messages, scalable broadcast and private participation at the same time. Anyone can join a channel through its public link, so encrypting its content would protect nothing; protecting who participates does. SimpleX channels make participation private: relays see the content, but not subscribers' identities or network addresses, and participation in different channels cannot be linked. Details: [SimpleX Channels](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md), [channels whitepaper](https://simplex.chat/docs/protocol/channels-overview.md).
+
+## Is SimpleX audited?
+
+Yes. Trail of Bits assessed the implementation in October 2022 and reviewed the cryptographic design in July 2024. A third audit was completed in 2026 and will be published. Reports: [2022](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf), [2024](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf).
+
+## What are SimpleX's limitations?
+
+- Post-quantum key exchange is used in direct conversations, not yet in groups.
+- An observer who can watch the traffic of both users can confirm that they communicate.
+- Resolving a public name reveals interest in that name to one resolver server, but not who asked.
+
+## How does SimpleX compare with Signal, Session, Matrix, Briar and others?
+
+Every other messaging network assigns users an identifier: Signal and WhatsApp use phone numbers, Matrix uses `@user:server` IDs, and Session, Briar, Cwtch and Nostr identify users by long-term public keys or onion addresses. These identifiers let the network, or anyone observing it, link a user's conversations. SimpleX has none. A side-by-side comparison of encryption properties is on the [messaging page](https://simplex.chat/messaging/#messengers-comparison), and a technical comparison with peer-to-peer protocols is in [How SimpleX works](https://simplex.chat/docs/simplex.md).
+
+## Can people find or contact me without my consent?
+
+No. Nobody can contact you unless you share a one-time link or your address. An address is optional and can be changed or deleted without losing contacts.
+
+## Who controls the network?
+
+Nobody alone. Anyone can run servers. SimpleX Chat and Flux are preset in the app, and when both are enabled the app uses servers of both operators in each conversation. The SimpleX Network Consortium, an agreement between the non-profit SimpleX Network Foundation and SimpleX Chat, licenses the protocol to the foundation permanently, so it stays available regardless of who owns the company. Details: [blog](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md).
+
+## Is SimpleX free and open source?
+
+Yes. The apps are free, and the code is open source under AGPL-3.0: [github.com/simplex-chat](https://github.com/simplex-chat).
+
+## How will SimpleX Chat make money?
+
+Private messaging stays free. Channels and businesses will pay for public names, business messaging and servers for big channels. Users have already donated over $650,000. Details: [Wefunder memo](https://simplex.chat/wefunder.md).
+
+## What are SimpleX public names?
+
+Optional, human-readable names for channels and businesses, such as `#example` or `@example.simplex`, registered on a public blockchain and controlled only by their owner's key. Names do not identify users and are not needed to use the network. Sale starts on 12 December 2026. Details: [public names whitepaper](https://simplex.chat/docs/protocol/names-overview.md).
+
+## How can AI agents and developers use SimpleX?
+
+An agent connects to the network like a person: it holds its own keys and addresses, and no platform account is needed. See [SimpleX for AI agents and developers](https://simplex.chat/llms/agents.md).
+
+## How can I invest in SimpleX Chat?
+
+SimpleX Chat runs an equity crowdfunding offering on Wefunder: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat). The memo is reproduced at [simplex.chat/wefunder.md](https://simplex.chat/wefunder.md). Investing involves a high degree of risk, including the possible loss of your investment.
+
+## How do I contact the SimpleX team?
+
+In the SimpleX Chat app, open the "Ask SimpleX Team" chat, or connect via [simplex.chat/contact](https://simplex.chat/contact#/?v=2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion). A support bot answers first; send `/team` to reach the team.
+
+---
+
+Source: https://simplex.chat/docs/simplex.md
+
+| Updated 07.02.2023 | Languages: EN, [FR](https://simplex.chat/docs/lang/fr/simplex.html), [CZ](https://simplex.chat/docs/lang/cs/simplex.html), [PL](https://simplex.chat/docs/lang/pl/simplex.html) |
+# SimpleX platform - motivation and comparison
+
+## Problems
+
+Existing chat platforms and protocols have some or all of the following problems:
+
+- Lack of privacy of the user profile and contacts (meta-data privacy).
+- No protection (or only optional protection) of [E2EE][1] implementations from MITM attacks via provider.
+- Unsolicited messages (spam and abuse).
+- Lack of data ownership and protection.
+- Complexity of usage for all non-centralized protocols to non-technical users.
+
+The concentration of the communication in a small number of centralized platforms makes resolving these problems quite difficult.
+
+## Proposed solution
+
+Proposed stack of protocols solves these problems by making both messages and contacts stored only on client devices, reducing the role of the servers to simple message relays that only require authorization of messages sent to the queues, but do NOT require user authentication - not only the messages but also the metadata is protected because users do not have any identifiers assigned to them - unlike with any other platforms.
+
+See [SimpleX whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md) for more information on platform objectives and technical design.
+
+## Why use SimpleX
+
+## SimpleX unique approach to privacy and security
+
+Everyone should care about privacy and security of their communications - even ordinary conversations can put you in danger.
+
+### Full privacy of your identity, profile, contacts and metadata
+
+**Unlike any other existing messaging platform, SimpleX has no identifiers assigned to the users** - it does not use phone numbers (like Signal or WhatsApp), domain-based addresses (like email, XMPP or Matrix), usernames (like Telegram), public keys or even random numbers (like all other messengers) to identify its users - we do not even know how many people use SimpleX.
+
+To deliver the messages instead of user identifiers that all other platforms use, SimpleX uses the addresses of unidirectional (simplex) message queues. Using SimpleX is like having a different email address or a phone number for each contact you have, but without the hassle of managing all these addresses. In the near future SimpleX apps will also change the message queues automatically, moving the conversations from one server to another, to provide even better privacy to the users.
+
+This approach protects the privacy of who are you communicating with, hiding it from SimpleX platform servers and from any observers. You can further improve your privacy by configuring your network access to connect to SimpleX servers via some overlay transport network, e.g. Tor.
+
+### The best protection against spam and abuse
+
+As you have no identifier on SimpleX platform, you cannot be contacted unless you share a one-time invitation link or an optional temporary user address. Even with the optional user addresses, while they can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+### Complete ownership, control and security of your data
+
+SimpleX stores all user data on client devices, the messages are only held temporarily on SimpleX relay servers until they are received.
+
+We use portable database format that can be used on all supported devices - we will soon add the ability to export the chat database from the mobile app so it can be used on another device.
+
+Unlike servers of federated networks (email, XMPP or Matrix), SimpleX servers do not store user accounts, they simply relay messages to the recipients, protecting the privacy of both parties. There are no identifiers or encrypted messages in common between sent and received traffic of the server, thanks to the additional encryption layer for delivered messages. So if anybody is observing server traffic, they cannot easily determine who is communicating with whom (see [SimpleX whitepaper](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md) for the known traffic correlation attacks).
+
+### Users own SimpleX network
+
+You can use SimpleX with your own servers and still communicate with people using the servers that are pre-configured in the apps or any other SimpleX servers.
+
+SimpleX platform uses an open protocol and provides SDK to create chat bots, allowing implementation of services that users can interact with via SimpleX Chat apps – we are really looking forward to see what SimpleX services can be built.
+
+If you are considering developing with the SimpleX platform, whether for chat bot services for SimpleX app users or to integrate the SimpleX Chat library into your mobile apps, please get in touch for any advice and support.
+
+## Comparison with other protocols
+
+|                                                |    SimpleX chat    | Signal, big platforms |  XMPP, Matrix   |  P2P protocols  |
+| :--------------------------------------------- | :----------------: | :-------------------: | :-------------: | :-------------: |
+| Requires user identifiers                      |    No = private    |    Yes<sup>1</sup>    | Yes<sup>2</sup> | Yes<sup>3</sup> |
+| Possibility of MITM                            |    No = secure     |    Yes<sup>4</sup>    |       Yes       |       Yes       |
+| Dependence on DNS                              |   No = resilient   |          Yes          |       Yes       |       No        |
+| Single operator or network                     | No = decentralized |          Yes          |       No        | Yes<sup>5</sup> |
+| Central component or other network-wide attack |   No = resilient   |          Yes          | Yes<sup>2</sup> | Yes<sup>6</sup> |
+
+1. Usually based on a phone number, in some cases on usernames.
+2. DNS based.
+3. Public key or some other globally unique ID.
+4. If operator’s servers are compromised.
+5. While P2P networks and cryptocurrency-based networks are distributed, they are not decentralized - they operate as a single network, with a single namespace of user addresses.
+6. P2P networks either have a central authority or the whole network can be compromised - see the next section.
+
+## Comparison with [P2P][9] messaging protocols
+
+There are several P2P chat/messaging protocols and implementations that aim to solve privacy and centralisation problem, but they have their own set of problems that makes them less reliable than the proposed design, more complex to implement and analyse and more vulnerable to attacks.
+
+1. [P2P][9] networks use some variant of [DHT][10] to route messages/requests through the network. DHT implementations have complex designs that have to balance reliability, delivery guarantee and latency. The proposed design has both better delivery guarantees and lower latency (the message is passed multiple times in parallel, through one node each time, using servers chosen by the recipient, while in P2P networks the message is passed through `O(log N)` nodes sequentially, using nodes chosen by the algorithm).
+
+2. The proposed design, unlike most P2P networks, has no global user identifiers of any kind, even temporary.
+
+3. P2P itself does not solve [MITM attack][2] problem, and most existing solutions do not use out-of-band messages for the initial key exchange. The proposed design uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent][11]). The proposed design is transport agnostic - it can work over standard web protocols, and the servers can be deployed on the same domains as the websites.
+
+5. All known P2P networks are likely to be vulnerable to [Sybil attack][12], because each node is discoverable, and the network operates as a whole. Known measures to reduce the probability of the Sybil attack either require a centralized component or expensive [proof of work][13]. The proposed design, on the opposite, has no server discoverability - servers are not connected, not known to each other and to all clients. The SimpleX network is fragmented and operates as multiple isolated connections. It makes network-wide attacks on SimpleX network impossible - even if some servers are compromised, other parts of the network can operate normally, and affected clients can switch to using other servers without losing contacts or messages.
+
+6. P2P networks are likely to be [vulnerable][14] to [DRDoS attack][15]. In the proposed design clients only relay traffic from known trusted connections and cannot be used to reflect and amplify the traffic in the whole network.
+
+[1]: https://en.wikipedia.org/wiki/End-to-end_encryption
+[2]: https://en.wikipedia.org/wiki/Man-in-the-middle_attack
+[9]: https://en.wikipedia.org/wiki/Peer-to-peer
+[10]: https://en.wikipedia.org/wiki/Distributed_hash_table
+[11]: https://en.wikipedia.org/wiki/BitTorrent
+[12]: https://en.wikipedia.org/wiki/Sybil_attack
+[13]: https://en.wikipedia.org/wiki/Proof_of_work
+[14]: https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent
+[15]: https://en.wikipedia.org/wiki/Denial-of-service_attack#Reflected_attack
+
+---
+
+Source: https://simplex.chat/docs/glossary.md
+
+# Glossary
+
+Choosing a private messenger requires the understanding of many technical terms, that many users, even quite technical, often misunderstand. This list is aiming to fill this knowledge gap. Please suggest any changes or additions.
+
+While this glossary aims to be factual and objective, it is not completely unbiased. We designed SimpleX to be the most private, secure and resilient communication network, and some definitions reflect this view.
+
+## 2-factor key exchange
+
+The ability of communication service to ensure the security of the [key agreement protocol](#key-agreement-protocol) against [man-in-the-middle](#man-in-the-middle-attack).
+
+## Address portability
+
+Similarly to [phone number portability](https://en.wikipedia.org/wiki/Local_number_portability) (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many [federated networks](#federated-network) support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.
+
+## Anonymous credentials
+
+The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.
+
+[Digital credential on Wikipedia](https://en.wikipedia.org/wiki/Digital_credential)
+
+## Blockchain
+
+In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of [Merkle directed acyclic graphs](#merkle-directed-acyclic-graph).
+
+In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some [consensus protocol](https://en.wikipedia.org/wiki/Consensus_(computer_science)).
+
+[Wikipedia](https://en.wikipedia.org/wiki/Blockchain)
+
+## Break-in recovery
+
+[Post-compromise security](#post-compromise-security).
+
+## Centralized network
+
+Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.
+
+## Content padding
+
+[Message padding](#message-padding).
+
+## Decentralized network
+
+Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.
+
+The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.
+
+## Defense in depth
+
+Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.
+
+In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.
+
+SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:
+- double ratchet algorithm for [end-to-end encryption](#end-to-end-encryption) with [perfect forward secrecy](#forward-secrecy) and [post-compromise security](#post-compromise-security),
+- additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,
+- TLS with only strong ciphers allowed,
+- mitigation of [man-in-the-middle attack](#man-in-the-middle-attack) on client-server connection via server offline certificate verification,
+- mitigation of replay attacks via signing over transport channel binding,
+- multiple layers of [message padding](#message-padding) to reduce efficiency of traffic analysis,
+- mitigation of [man-in-the-middle attack](#man-in-the-middle-attack) on client-client out-of-band channel when sending the invitation,
+- rotation of delivery queues to reduce efficiency of traffic analysis,
+- etc.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Defence_in_depth)
+
+## Double ratchet algorithm
+
+It is used by two parties to exchange [end-to-end encrypted](#end-to-end-encryption) messages. The parties will use some [key agreement protocol](#key-agreement-protocol) to agree on the initial shared secret key.
+
+Double Ratchet algorithm provides [perfect forward secrecy](#forward-secrecy) and [post-compromise security](#post-compromise-security). It is [designed by Signal](https://signal.org/docs/specifications/doubleratchet), and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.
+
+## End-to-end encryption
+
+A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.
+
+End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See [key agreement protocol](#key-agreement-protocol). This key exchange can be compromised via [man-in-the-middle attack](#man-in-the-middle-attack), particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.
+
+[Wikipedia](https://en.wikipedia.org/wiki/End-to-end_encryption)
+
+## Federated network
+
+Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.
+
+The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no [address portability](#address-portability), 3) the security and privacy are inevitably worse than with the centralized networks.
+
+[Federation on Wikipedia](https://en.wikipedia.org/wiki/Federation_(information_technology))
+
+## Forward secrecy
+
+Also known as perfect forward secrecy, it is a feature of a [key agreement protocol](#key-agreement-protocol) that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Forward_secrecy)
+
+## Key agreement protocol
+
+Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for [end-to-end encryption](#end-to-end-encryption) to work. Unless it is possible to secure the key exchange via [some second factor](#2-factor-key-exchange), e.g. security code verification, it can be vulnerable to [man-in-the-middle attack](#man-in-the-middle-attack).
+
+[Wikipedia](https://en.wikipedia.org/wiki/Key-agreement_protocol)
+
+## Key exchange
+
+[Key agreement protocol](#key-agreement-protocol).
+
+## Man-in-the-middle attack
+
+The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.
+
+This attack can be used to compromise [end-to-end encryption](#end-to-end-encryption) by intercepting public keys during [key exchange](#key-agreement-protocol), substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.
+
+Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.
+
+To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Man-in-the-middle_attack).
+
+## Merkle directed acyclic graph
+
+Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.
+
+This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with [blockchain](#blockchain).
+
+The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in [IPFS](https://en.wikipedia.org/wiki/InterPlanetary_File_System) and will be used in decentralized SimpleX groups.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Merkle_tree).
+
+## Message padding
+
+Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Padding_(cryptography)).
+
+## Onion routing
+
+A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.
+
+The most widely used onion network is [Tor](https://en.wikipedia.org/wiki/Tor_(network)).
+
+Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Onion_routing)
+
+## Overlay network
+
+Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.
+
+SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Overlay_network)
+
+## Non-repudiation
+
+The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to [repudiation](#repudiation). While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Non-repudiation)
+
+## Pairwise pseudonymous identifier
+
+Generalizing [the definition](https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier) from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.
+
+In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.
+
+## Peer-to-peer
+
+Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.
+
+The advantage is that the participants do not depend on any servers. There are [multiple downsides](https://simplex.chat/docs/simplex.md#comparison-with-p2p-messaging-protocols) to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with [proxied P2P](#proxied-peer-to-peer) architecture.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Peer-to-peer).
+
+## Perfect forward secrecy
+
+[Forward secrecy](#forward-secrecy).
+
+## Post-compromise security
+
+The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. [Double-ratchet algorithm](#double-ratchet-algorithm) has this quality.
+
+## Post-quantum cryptography
+
+Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is *proven* to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Post-quantum_cryptography)
+
+## Privacy
+
+Someone's right to keep (or the state when they keep) their personal matters and relationships secret (e.g., [Cambridge dictionary](https://dictionary.cambridge.org/dictionary/english/privacy)). Privacy of communication systems should include the privacy of connections and meta-data, not only the privacy of the content of messages. [End-to-end encryption](#end-to-end-encryption) on its own does not provide privacy, as it only protects message content and not connections or meta-data.
+
+[Wikipedia](https://en.wikipedia.org/wiki/Privacy)
+
+## Proxied peer-to-peer
+
+Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.
+
+## Recovery from compromise
+
+[Post-compromise security](#post-compromise-security).
+
+## Repudiation
+
+The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.
+
+See also [non-repudiation](#non-repudiation).
+
+## User identity
+
+In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see [this comparison](https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols).
+
+---
+
+Source: https://simplex.chat/faq.md
+
+# Frequently Asked Questions
+
+[How to use it](#how-to-use-it)
+- [How do I connect to people?](#how-do-i-connect-to-people)
+- [I have nobody to chat with! Where can I find any groups?](#i-have-nobody-to-chat-with-where-can-i-find-any-groups)
+- [What is database? What can I do with it?](#what-is-database-what-can-i-do-with-it)
+- [Can I send files over SimpleX? ](#can-i-send-files-over-simplex)
+- [What’s incognito profile?](#whats-incognito-profile)
+- [How do invitations work?](#how-do-invitations-work)
+- [How to configure and delete groups?](#how-to-configure-and-delete-groups)
+- [Are there any reactions to messages? Can I answer specific messages directly?](#are-there-any-reactions-to-messages-can-i-answer-specific-messages-directly)
+- [What do checkmarks mean?](#what-do-checkmarks-mean)
+- [I want to see when my contacts read my messages](#i-want-to-see-when-my-contacts-read-my-messages)
+- [Can I use the same profile on desktop? Do messages sync cross-platform?](#can-i-use-the-same-profile-on-desktop-do-messages-sync-cross-platform)
+- [Why cannot I delete messages I sent from my contact's device?](#why-cannot-i-delete-messages-i-sent-from-my-contacts-device)
+- [What do group roles mean?](#what-do-group-roles-mean)
+- [I don't want to share a web link or a QR code. How can I connect?](#i-dont-want-to-share-a-web-link-or-a-qr-code-how-can-i-connect)
+- [How to change servers to my own](#how-to-change-servers-to-my-own)
+
+[Troubleshooting](#troubleshooting)
+- [I do not receive messages or message notifications](#i-do-not-receive-messages-or-message-notifications)
+- [I do not see the second tick on the messages I sent](#i-do-not-see-the-second-tick-on-the-messages-i-sent)
+- [I see image preview but cannot open the image](#i-see-image-preview-but-cannot-open-the-image)
+- [I cannot play a voice message](#i-cannot-play-a-voice-message)
+- [Audio or video calls do not connect](#audio-or-video-calls-do-not-connect)
+- [Audio or video calls without e2e encryption](#audio-or-video-calls-without-e2e-encryption)
+- [I clicked the link to connect, but could not connect](#i-clicked-the-link-to-connect-but-could-not-connect)
+- [I do not know my database passphrase](#i-do-not-know-my-database-passphrase)
+- [My mobile app does not connect to desktop app](#my-mobile-app-does-not-connect-to-desktop-app)
+
+[Privacy and security](#privacy-and-security)
+- [Does SimpleX support post quantum cryptography?](#does-simplex-support-post-quantum-cryptography)
+- [Why can't I use the same profile on different devices?](#why-cant-i-use-the-same-profile-on-different-devices)
+- [What user data can be provided on request?](#what-user-data-can-be-provided-on-request)
+- [Does SimpleX protect my IP address?](#does-simplex-protect-my-ip-address)
+- [Doesn't private message routing reinvent Tor?](#doesnt-private-message-routing-reinvent-tor)
+- [Why don't you embed Tor in SimpleX Chat app?](#why-dont-you-embed-tor-in-simplex-chat-app)
+- [Can I host my own relays?](#can-i-host-my-own-relays)
+
+[Funding and business model](#funding-and-business-model)
+- [How are you funded?](#how-are-you-funded)
+- [Why VCs?](#why-vcs)
+- [What will be the business model?](#what-will-be-the-business-model)
+
+## How to use it
+
+### How do I connect to people?
+
+Tap "pencil" button in the right corner, then "Create 1-time link". Share the link with the person you want to connect to. Your contact has to paste the link to the app's search bar. The link can also be opened via the browser, once the app is installed.
+
+Alternatively, you can show the QR code when meeting in person or in a video call.
+
+It is safe to share this link over any communication channel, it contains only public keys and can only be used once.
+
+If you want to share your address publicly, so that many people can connect to you, use your SimpleX address instead of 1-time links. Tap your profile image/avatar, then Your SimpleX address. Once you create the address, you can share it in social media profiles, email signature, etc. See [the comparison of SimpleX address with 1-time links](https://simplex.chat/docs/guide/making-connections.md#comparison-of-1-time-invitation-links-and-simplex-contact-addresses).
+
+### I have nobody to chat with! Where can I find any groups?
+
+Please check our [Groups Directory](https://simplex.chat/docs/directory.md) in the first place. You might find some interesting groups and meet even more interesting people.
+
+### What is database? What can I do with it?
+
+Database is essential for SimpleX Chat to function properly. In comparison to centralized messaging providers, it is _the user_ who is responsible for taking care of their data. On the other hand, user is sure that _nobody but them_ has access to it. Please read more about it: [Database](https://simplex.chat/docs/guide/managing-data.md).
+
+### Can I send files over SimpleX?
+
+Of course! While doing so, you are using a _state-of-the-art_ protocol that greatly reduces metadata leaks. Please read more about it: [XFTP Protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md).
+
+### What’s incognito profile?
+
+This feature is unique to SimpleX Chat – it is independent from chat profiles.
+
+When "Incognito Mode” is turned on, your currently chosen profile name and image are hidden from your new contacts. It allows anonymous connections with other people without any shared data – when you make new connections or join groups via a link a new random profile name will be generated for each connection.
+
+### How do invitations work?
+
+It is quite a complex process, but fortunately all of this happens in the background, so it's simple to use.
+
+Whenever somebody connects to you via your address, they basically ask your client whether they want to establish connection. After that, you can either agree or disagree.
+If interested, please read more: [Addresses and invitations](https://simplex.chat/docs/guide/making-connections.md).
+
+### How to configure and delete groups?
+
+Please check: [Users guide](https://simplex.chat/docs/guide/secret-groups.md).
+
+### Are there any reactions to messages? Can I answer specific messages directly?
+
+Yes! Currently, there are six emojis available. What's more, you can respond to specific message by holding it and selecting _Reply_.
+
+### What do checkmarks mean?
+
+It's quite simple:
+- one checkmark - message is delivered to the relay (the server).
+- two checkmarks - message is delivered to the recipient's device.
+"sent" means accepted by the relay for delivery, "delivered" - stored on the recipient device.
+
+Also see: [I do not see the second tick on the messages I sent](#i-do-not-see-the-second-tick-on-the-messages-i-sent)
+
+### I want to see when my contacts read my messages
+
+To know when your contact reads your messages, your contact's app has to send you a confirmation message. And vice versa, for your contact to know when you read the message, your app has to send a confirmation message.
+
+The important questions for this feature:
+- do you always want that your contacts can see when you read all their messages? Probably, even with your close friends, sometimes you would prefer to have time before you answer their message, and also have a plausible deniability that you have not seen the message. And this should be ok - in the end, this is your device, and it should be for you to decide whether this confirmation message is sent or not, and when it is sent.
+- what practical problems an automatic notification sent to your contacts when you read the message solves for you compared with you simply adding a reaction to a message or sending a quick reply?
+
+Overall, it seems that this feature is more damaging to your communications with your contacts than it is helpful. It keeps senders longer in the app, nervously waiting for read receipts, exploiting addictive patterns - having you spend more time in the app is the reason why it is usually present in most messaging apps. It also creates a pressure on the recipients to reply sooner, and if read receipts are opt-in, it creates a pressure to enable it, that can be particularly damaging in any relationships with power imbalance.
+
+We think that delivery receipts are important and equally benefit both sides as the conversation, as they confirm that communication network functions properly. But we strongly believe that read receipts are an anti-feature that only benefits the app developers, and hurts the relations between the app users. So we are not planning to add it even as opt-in. In case you want your contact to know you've read the message put a reaction to it. And if you don't want them to know it - it is also ok, what your device sends should be under your control.
+
+### Can I use the same profile on desktop? Do messages sync cross-platform?
+
+You can use your profile from mobile device on desktop. However, to do so you need to be on the same network, both on your mobile and desktop. More about it: [Release info](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol).
+
+### Why cannot I delete messages I sent from my contact's device?
+
+In SimpleX Chat, you and your contacts can delete the messages you send from recipients' devices if you both agree to that within 24 hours of sending it. To be able to do that you both have to enable "Delete for everyone" option in Contact preferences - tap on the contact's name above the conversation to get there.
+
+You can also revoke the files you send. If the recipients did not yet receive the file, they will not be able to receive it after the file is revoked.
+
+This is different from most other messengers that allow deleting messages from the recipients' devices without any agreement with the recipients.
+
+We believe that allowing deleting information from your device to your contacts is a very wrong design decision for several reasons:
+1) it violates your data sovereignty as the device owner - once you are in possession of any information, you have the rights to retain it, and any deletion should be agreed with you. And security and privacy is not possible if users don't have sovereignty over their devices.
+2) it may be a business communication, and either your organization policy or a compliance requirement is that every message you receive must be preserved for some time.
+3) the message can contain a legally binding promise, effectively a contract between you and your contact, in which case you both need to keep it.
+4) the messages may contain threat or abuse and you may want to keep them as a proof.
+5) you may have paid for the message (e.g., it can be a design project or consulting report), and you don't want it to suddenly disappear before you had a chance to store it outside of the conversation.
+
+It is also important to remember, that even if your contact enabled "Delete for everyone", you cannot really see it as a strong guarantee that the message will be deleted. Your contact's app can have a very simple modification (a one-line code change), that would prevent this deletion from happening when you request it. So you cannot see it as something that guarantees your security from your contacts.
+
+When "Delete for everyone" is not enabled, you can still mark the sent message as deleted within 24 hours of sending it. In this case the recipient will see it as "deleted message", and will be able to reveal the original message.
+
+### What do group roles mean?
+
+Groups support 5 member roles: owner, admin, moderator, member and observer.
+
+An observer can:
+- add reactions
+- send reports
+- talk to admins via "Chat with admins"
+
+A member can:
+- send messages
+
+A moderator can:
+- approve members in review ("knocking")
+- moderate messages<sup>*</sup>
+- block members temporarily<sup>*</sup>
+- participate in "Chats with members"
+
+An admin can:
+- add and remove members<sup>*</sup>
+- change member roles<sup>*</sup>, including their own
+- create group links (but the new members will join via them, so use links of admins who are always online).
+
+A group owner can:
+- edit group profile
+- delete the group
+
+Each role can do everything that the previous roles can, except moderators and higher cannot send reports or "Chat with admins".
+
+<sup>*</sup>Any actions affecting members or their messages can only be applied to members of the same or lower role (so admins can't demote owners or promote anybody to owners, etc., but they can demote other admins and themselves, or make anybody an admin).
+
+### I don't want to share a web link or a QR code. How can I connect?
+
+You can replace the server part of the link (e.g., `https://smp18.simplex.im/`) with `simplex:/` and add `?h=smp18.simplex.im` (replace it with server of your link) to the end of the link. Then it will not be possible to use it in a web browser, but it will be recognized by SimpleX Chat app.
+
+For example, this link: `https://smp18.simplex.im/i#E74vSxMwDnEx6DAvRCZmzBeZwwAseJUD/yVTHjaaH_EzL19DG7fvd46Mjry3IBqYT0UMo5G7l4jQ`
+
+becomes: `simplex:/i#E74vSxMwDnEx6DAvRCZmzBeZwwAseJUD/yVTHjaaH_EzL19DG7fvd46Mjry3IBqYT0UMo5G7l4jQ?h=smp18.simplex.im`
+
+### How to change servers to my own?
+
+Add your server in Settings -> Network & servers -> Your servers. If you have multiple profiles, you need to add your server in every profile.
+After that, disable all preset servers. If you have multiple profiles, you must first add your server to all profiles for this option to be available.
+
+To resolve SimpleX public names, if your server does not support it, you may leave preset servers enabled only for resolving the public names.
+
+Please note: configured servers only determine which servers will be used for the new connections (members/contacts). Previously created connections don't switch automatically. You can manually switch all existing contacts and small/important groups (each member needs to be switched), and then leave and re-join all large groups.
+You can switch contacts/members manually to another server by going to their profile and clicking on "Change receiving address", note that the current server must be online for the address change to work.
+
+## Troubleshooting
+
+### I do not receive messages or message notifications
+
+There may be several reasons messages are not delivered to you from your contact:
+
+**You or your contact cannot connect to the server that you use to receive messages from your contact.**
+
+You can check which server is used to receive messages by tapping the contact name above the conversation.
+
+You can also run tests for this server from the app Network settings.
+
+Please ask your contact if they have a single tick on the message to determine if the message failed to send or if you fail to receive it.
+
+**Message delivery got stuck because of some unresolved bug.**
+
+Fully restarting the app is the workaround to resume message delivery.
+
+To do it on iOS, simply close the app (swipe up from the opened apps) and open it again.
+
+To do it on Android - choose Restart from the app settings, simply closing and re-opening the app will not restart the messaging service.
+
+**Your Android operating system kills the app while it is in background.**
+
+Check battery settings for the app - it should be set to Unrestricted.
+
+For some devices, there may be additional options to prevent the app from being killed - e.g., on Xiaomi you need to enable Auto Start setting for the app. Please consult https://dontkillmyapp.com site for any additional settings for your device.
+
+**Why my notifications aren't working on iOS**
+
+Check the color of the bolt icon next to Notifications in app settings - it should be green.
+
+If it's not, please open notifications, disable them (choose Off / Local), and then enable again - you should do it when you have Internet connection.
+
+Check if your push server has been restarted at time of the issue (Notifications -> Push server) at https://status.simplex.chat if it has been restarted, you may not receive notifications from that time.
+
+If device was offline, you may need to open the app to start receiving notifications.
+
+If the above didn't help, the reason could be that iOS failed to issue notification token - we have seen this issue several times. In this case, restarting the whole device should help.
+
+In some cases notifications may still not work, iOS notifications are hard to do right in a decentralized app, we will be improving them soon to be more reliable.
+
+**Messaging server or notification server is under maintenance**
+
+Please check the current status of preset servers at [https://status.simplex.chat](https://status.simplex.chat). You can also connect to status bot via QR code on that page - it will send the updates when the server is offline for maintenance, and also when the new versions of the app are released.
+
+### I do not see the second tick on the messages I sent
+
+You may not have the second tick on your sent messages for these reasons:
+
+- your contact is not online, and did not receive your message.
+- possibly, message delivery to your contact or to you is disrupted - see [I do not receive messages](#i-do-not-receive-messages-or-message-notifications) - please check with your contact via some other channel if they received your message. If the message was delivered, then it means your device could fail to receive the delivery notification.
+- possibly, your contact disabled sending delivery receipts - it can be disabled for specific or for all contacts - please check with your contact.
+
+### I see image preview but cannot open the image
+
+It can be for these reasons:
+- your contact did not finish uploading the image file, possibly closing the app too quickly. When the image file is fully uploaded there will be a tick in the _top right corner_ of the image.
+- your device fails to receive it. Please check server connectivity and run server tests, and also try increasing network timeouts in Advanced network settings. File reception was substantially improved in v5.7 - please make sure you are using the latest version.
+- file expired and can no longer be received. Files can be received only for 2 days after they were sent, after that they won't be available and will show X in the top right corner.
+
+### I cannot play a voice message
+
+This can happen for similar reasons as for [images](#i-see-image-preview-but-cannot-open-the-image).
+
+Please check your network settings and make sure you use the latest version of the app.
+
+Please report such issues if you use v5.7 or newer.
+
+### Audio or video calls do not connect
+
+App uses WebRTC for calls. Please check that you can connect to the servers configured in the app: stun.simplex.im and turn.simplex.im - see [troubleshooting WebRTC](https://simplex.chat/docs/webrtc.md#troubleshoot).
+
+If you can connect to the server, please report this issue to us privately, including the following information:
+
+- how you connect to the network: WiFi, mobile network, VPN provider - the more information you can provide the better.
+
+- app version and platform. For mobile apps, it would help if you can make a screen recording from both devices during unsuccessful calls and share with us.
+
+- if the issue is on desktop app, which browser is used for calls. In this case also please check browser console during the call and send us the log, ideally from both sides of the unsuccessful calls.
+
+Thank you for helping us debug and improve calls.
+
+### Audio or video calls without e2e encryption
+
+During the call, the app indicates whether or not the call has end-to-end encryption.
+
+If one of the call parties uses Android (or desktop) app, the call would use Android system webview (or browser). Some older systems do not support media stream encryption, in which case the call will connect without it.
+
+To determine whether it is the limitation of your, your contact's or both devices:
+- if some of your calls have e2e encryption but some don't, then it's certainly the old webview version or browser of your contacts - please ask them to upgrade.
+- if you are not sure, you can check at what point "no e2e encryption" appears:
+  - if it is shown when the call rings on your device, then your contact's device does not support call encryption.
+  - if it is shown on your screen as soon as you start the call, then your device does not support call encryption.
+  - if in the beginning of the call your device shows "e2e encryption" but when your contact accepts the call it changes to "no e2e encryption", then it is only your contact's device that does not support it.
+
+You need to upgrade webview (some Android systems allow it), Android system or the device to have support for e2e encryption in the calls - all modern WebViews (and browsers) support it.
+
+### I clicked the link to connect, but could not connect
+
+If you confirmed the connection in the app, pending connection will be shown in the list of chats - you can assign the name to it, so you know who it was when your contact is connected (e.g., if they choose some name you don't recognize).
+
+For connection to complete, your contact has to be online and have the app running - please ask them to open the app, and try to have the app open at the same time - it will help to complete the connection faster.
+
+Once the connection is established you don't need to be online at the same time to send messages.
+
+### I do not know my database passphrase
+
+If you are prompted to enter database passphrase and you do not know it, this could have happened due to:
+- You may have forgotten the passphrase. (There is no other way to access your data).
+- Migration of app data from one device to another while using unsupported migration process, e.g. via iCloud backup. Use SimpleX Chat's own migration process in the app Settings.
+
+In the previous desktop app versions it could also happen in case of error during SimpleX Chat installation.
+
+You can resolve it by deleting the app's database: (WARNING: this results in deletion of all profiles, contacts and messages)
+- on Android/iOS, uninstall the app and install it again.
+- on Windows, delete folder `C:\AppData\Roaming\SimpleX`, you can find it by pressing Windows key + R and entering `%appdata%`.
+- on Linux/Mac, delete directories `~/.local/share/simplex` and `~/.config/simplex`, where `~` represents your home directory (/home/user)
+- on Flatpak, delete directory `~/.var/app/chat.simplex.simplex`.
+
+### My mobile app does not connect to desktop app
+
+1. Check that both devices are connected to the same network (e.g., it won't work if mobile is connected to mobile Internet and desktop to WiFi).
+2. If you use VPN on mobile, allow connections to local network in your VPN settings, or disable VPN.
+3. Allow SimpleX Chat on desktop to accept network connections in system firewall settings. You may choose a specific port in desktop app to accept connections, by default it uses a random port every time.
+4. Check that your WiFi router allows connections between devices (e.g., it may have an option for "device isolation", or similar).
+5. If you see an error "certificate expired", please check that your device clocks are synchronized within a few seconds.
+6. If iOS app fails to connect and shows an error containing "no route", check that local network connections are allowed for the app in system settings.
+
+Also see this post: https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol
+
+If none of the suggestions work for you, you can create a separate profile on each device and create a small group inviting both of your device profiles and your contact.
+
+## Privacy and security
+
+### Does SimpleX support post quantum cryptography?
+
+Yes! Please read more about how quantum-resistant encryption is added to SimpleX Chat and about various properties of end-to-end encryption in [this post](https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.md).
+
+### Why can't I use the same profile on different devices?
+
+SimpleX Chat apps support [linking of mobile and desktop apps](https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol) via secure quantum-resistant protocol. It allows using the profile on your mobile device from desktop clients.
+
+Seamlessly and securely using the same profile from two or more devices is a complex and unsolved problem. All apps that provide multi-device support do so at a cost of compromising security of end-to-end encryption. E.g., Session removed the Double Ratchet algorithm entirely to enable multi-device support, sacrificing forward secrecy. Signal provides multi-device support with Double Ratchet algorithm, but by [compromising its "break-in recovery" property](https://eprint.iacr.org/2021/626.pdf) (aka post-compromise security).
+
+To the best of our knowledge there is no end-to-end encrypted messenger that solved this problem without compromising security, but we believe that the solution is possible. We have considered several approaches:
+
+1. Convert each direct conversation into a group, where each device participates as a member. This is the approach that Signal and WhatsApp use, and while Signal implementation does not protect from a temporary compromise of long-term identity key (break-in recovery), such protection is possible. The downside of this approach is that the contacts and groups you participate in would know which device you use. Another possible attack is to send different messages to different devices, or to send messages to some devices but not to the others. This could lead to message history inconsistency or enable targeted attacks.
+
+2. Store the state of the Double Ratchet algorithm for each conversation in an encrypted container on the server, allowing concurrent access and modification by each device for encrypting and decrypting messages. We did not see this approach used in any of the messaging apps, but it is technically viable. This approach has no downsides of the first, but it would increase the time it takes to send and to receive messages, as each message would require additional access to the server.
+
+3. "Thin client" approach when user profile is stored on the server. The main challenge with this approach is to prevent the server knowing who connects to whom.
+
+Whichever approach we choose for multi-device support, it requires careful design and implementation, and there is no existing secure solution to copy from. While we value usability very highly, we will not be improving usability in a way that compromises users' security. We will take a slower path of designing and implementing a solution for multi-device that achieves a better trade-off between usability and security than currently offered.
+
+In the meantime, here are several secure options to enhance usability:
+- link mobile profiles with desktop app. It does not compromise security in any way.
+- create small groups with trusted contacts. These contacts would still know which device you use when you send the message, but it won't be shared with all contacts and groups you participate in. This approach is also secure, and it prevents devices being added to the conversation without user noticing.
+- use "[business address](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html#business-chats)" - the app would create a new small group with everybody who connects to you via your address, and you will be able to add your other devices to these groups.
+
+While these approaches are not as convenient as seamless multi-device support offered by other apps, they also do not compromise security to achieve that convenience.
+
+### What user data can be provided on request?
+
+Our objective is to consistently ensure that no user data and absolute minimum of the metadata required for the network to function is available for disclosure by any infrastructure operators, under any circumstances.
+
+Please see our [Privacy Policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md) and [Transparency Reports](https://simplex.chat/transparency/index.html).
+
+### Does SimpleX protect my IP address?
+
+Yes!
+
+SimpleX Chat from version 6.0 uses *private message routing* whenever you send messages to unknown servers (all servers in app network settings, both enabled and not, are considered "known").
+
+For private routing to work, the servers chosen by your contacts (and by the group members in your groups) must be upgraded to the recent versions. Messaging servers include support for private routing from v5.8, but we recommend using the latest versions.
+
+If the servers didn't upgrade, the messages would temporarily fail to deliver. You will see an orange warning icon on the message, and you can decide if you want to deliver them by connecting to these servers directly (it would require changing network settings). At the time of writing (August 2024), all preset servers and absolute majority of self-hosted servers we can see on the network support private message routing.
+
+With private routing enabled, instead of connecting to your contact's server directly, your client would "instruct" one of the known servers to forward the message, preventing the destination server from observing your IP address.
+
+Your messages are additionally end-to-end encrypted between your client and the destination server, so that the forwarding server cannot observe the destination addresses and server responses – similarly to how onion routing works. Private message routing is, effectively, a two-hop onion packet routing.
+
+Also, this connection is protected from man-in-the-middle attack by the forwarding server, as your client will validate destination server certificate using its fingerprint in the server address.
+
+You can optionally enable private message routing for all servers in Advanced network settings to complicate traffic correlation for known servers too. This will be default once the clients are improved to "know about" and to take into account network server operators.
+
+See [this post](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md#private-message-routing) for more details about how private message routing works.
+
+### Doesn't private message routing reinvent Tor?
+
+No, it does not!
+
+It provides better privacy for messaging than Tor, and it can be used with and without Tor or other means to additionally protect your traffic from known servers as well.
+
+Tor, VPN and other transport overlay networks route sockets, by creating long-lived TCP circuits between you and the destination server. While it protects your IP address, it does not protect your activity within this circuit. E.g., if you visit a website via Tor, it can still observe all pages you view within a session. Likewise, if you were connecting directly to a messaging server via Tor, this server would be able to list all message queues you send messages to.
+
+Private message routing routes packets (each message is one 16kb packet), not sockets. Unlike Tor and VPN, it does not create circuits between your client and destination servers. The forwarding server creates one shared session between itself and the destination, and forwards all messages from you and other clients to that destination server, mixing messages from many clients into a single TCP session.
+
+As each message uses its own random encryption key and random (non-sequential) identifier, the destination server cannot link multiple message queue addresses to the same client. At the same time, the forwarding server cannot observe which (and how many) addresses on the destination server your client sends messages to, thanks to e2e encryption between the client and destination server. In that regard, this design is similar to onion routing, but with per-packet anonymity, not per-circuit.
+
+This design is similar to mixnets (e.g. [Nym network](https://nymtech.net)), and it is tailored to the needs of message routing, providing better transport anonymity than general-purpose networks, like Tor or VPN. You still can use Tor or VPN to connect to known servers, to protect your IP address from them.
+
+### Why don't you embed Tor in SimpleX Chat app?
+
+[Tor](https://www.torproject.org) is a fantastic transport overlay network - we believe it might be the best there is right now. If its [threat model](https://support.torproject.org/about/attacks-on-onion-routing/) works for you, you absolutely should use it - SimpleX Chat app supports Tor via SOCKS proxy [since v3.1](https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.html#access-messaging-servers-via-tor), and SimpleX network servers can be available on both public and onion address at the same time [since v3.2](https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.html#using-onion-server-addresses-with-tor), improving anonymity of the users who use Tor.
+
+If you host your messaging server on the onion address only, the users who don't use Tor would still be able to message you via private message routing - all preset servers are configured to forward messages to onion-only servers.
+
+But there are many reasons not to embed Tor in the app:
+- it increases response latency, error rate, and battery usage, and we believe that for most users enabling Tor by default would be a bad trade-off.
+- it would require us regularly updating Tor library in the app, and your Tor integrity would depend on us – you would be "putting too many eggs in one basket".
+- some networks restrict Tor traffic, so the app UI would have to support advanced Tor configuration, diverting our limited resources from the core app features that benefit all users.
+- some countries have legislative restrictions on Tor usage, so we would have to support multiple app versions, also increasing our costs and slowing down the progress.
+
+The last, but not the least, it would create an unfair competitive advantage to Tor. We believe in competition, and we want our users to be able to choose which transport overlay network to use, based on what network threat model works best for them.
+
+If you want to use Tor or any other overlay network, such as i2p, [Nym network](https://nymtech.net), [Katzenpost](https://katzenpost.network), etc., you need to research their limitations, because none of them provides absolute anonymity against all possible attackers.
+
+And if after that research you decide to use Tor, it takes about 2 minutes to install and start [Orbot app](https://guardianproject.info/apps/org.torproject.android/). We believe that if it seems complex, then you *should not* be using Tor - it is an advanced technology that can only improve your privacy and anonymity if you understand its limitations and know how to configure it.
+
+### Can I host my own relays?
+
+Of course! Please check these tutorials: [SMP server](https://simplex.chat/docs/server.md) and [XFTP server](https://simplex.chat/docs/xftp-server.md).
+
+## Funding and business model
+
+### How are you funded?
+
+SimpleX Chat Ltd is funded by private investors and venture capital. As an open-source project, it is also being generously supported by donations as well. Read the posts [from 2023](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md#how-is-it-funded-and-what-is-the-business-model) and [from 2024](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) for more details.
+
+### Why VCs?
+
+Here are some reflections on VC funding being a necessity for a project at this scale, as well as sustainability and profitability for longtime operations: https://www.poberezkin.com/posts/2023-10-31-why-privacy-impossible-without-venture-funding.html
+
+And another perspective from a team member on the delicate balance of venture-backed and nonprofit structures, and the plans for the SimpleX network protocols to evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and transparent governance:
+[https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html](https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.md).
+
+### What will be the business model?
+
+We are focusing on product-market fit, and as such the business model is still a work in progress. However, the app will have a freemium model with extra features or capabilities for paid users (taking into consideration a potential formula like 5% paying $5/month is $3/user/year - ~90% gross profit margin).
+
+The other income stream would be via business services, for entities needing direct and customized support to integrate with the SimpleX protocol or related resources. There will also be a revenue-sharing model from customers to network operators, to provide an incentive for them to continue running nodes, which will increase decentralization and reliability of the network.
+
+Non-exploitative commercial models with fully open source code are not easy to achieve, and we’re committed to finding the best possible fit for our context. Everything will be fully communicated as this plan progresses.
+
+---
+
+Source: https://simplex.chat/docs/protocol/names-overview.md
+
+Revision 1, 2026-07-14
+
+# SimpleX Public Names for Channels and Businesses
+
+## Table of contents
+
+- [Introduction](#introduction)
+  - [Names](#names)
+  - [Use cases](#use-cases)
+  - [On-chain registry](#on-chain-registry)
+  - [Privacy considerations](#privacy-considerations)
+- [Architecture](#architecture)
+  - [Names and records](#names-and-records)
+  - [Resolution](#resolution)
+  - [Private decentralized RPC layer](#private-decentralized-rpc-layer)
+  - [Claiming and verification](#claiming-and-verification)
+- [Differences from ENS](#differences-from-ens)
+- [Security](#security)
+  - [Design objectives](#design-objectives)
+  - [Threat model](#threat-model)
+  - [Current gaps](#current-gaps)
+- [Future work](#future-work)
+- [Conclusion](#conclusion)
+
+
+## Introduction
+
+The SimpleX network provides communication without user identifiers - people connect by exchanging links out of band. This protects private communication, but public entities - channels and businesses - need to be discoverable. Today this requires distributing a long link, which is impossible to remember and can be deleted by the router that hosts it. SimpleX public names provide memorability and ease of connection without adding user identifiers.
+
+### Names
+
+A SimpleX name is a human-readable name, registered on a public blockchain, that resolves to SimpleX links: `#example.simplex` opens a channel (for the `.simplex` namespace, the short variant `#example` can also be used for channel names) and `@example.simplex` connects to a contact or business address. One name can include both links - a business can publish `@example.simplex` for customer conversations and `#example.simplex` for its announcement channel from a single registration. Names support subnames (`support.example.simplex`). A separate test namespace (`.testing`) is deployed for early adopters before the main namespace launches.
+
+A name is not an account and not an identity. It is a record that maps a human-readable string to the links a channel or business already has, controlled by a cryptographic key that only its owner holds. The network does not use or require names; they are a discovery layer on top of it, described in this document.
+
+This document covers the naming layer built for [SimpleX Channels](https://simplex.chat/docs/protocol/channels-overview.md) and the [SimpleX network](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md). For the user-facing registration steps see [Registering a SimpleX name](https://simplex.chat/docs/guide/register-simplex-name.md); for protocol-level details see the resolver commands in the [SMP protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/simplex-messaging.md).
+
+### Use cases
+
+Names are intended for entities that are already public:
+
+- **Channels.** A channel reachable as `#example` can be easily shared in many ways - conversation, print, social media, and messages. If the channel's link is removed or blocked, the owner can point the name to a new link, and the channel remains reachable via the same name.
+
+- **Businesses and organizations.** A business address reachable as `@example.simplex` gives customers a way to start a conversation without scanning a QR code or trusting a link from a search result.
+
+- **Creators and public figures.** Anyone publishing to an audience can be reachable by name while their audience remains private.
+
+Names are opt-in and are only useful for public entities. Private users do not need them. Even when an entity uses a name, the network cannot track who connects to it - the communication graph remains private.
+
+### On-chain registry
+
+Names must be globally unique, so they require a shared registry. Every conventional registry design places names under an operator's control:
+
+- **A platform registry** (usernames in messaging apps) is owned by the operator: names can be revoked, impersonated, or reassigned, and the platform sees who looks up whom.
+
+- **DNS** is subject to domain seizure at the registrar and registry level, and requires registrant records.
+
+A record on a public blockchain has no operator: only the holder of the registration key can change what a name points to, and no authority can delete it. This mitigates censorship at these levels:
+
+- **SMP routers.** The router that hosts a link can delete it, and the link stops working for everyone who saved it. A name is not affected: the owner points it to a new link on a different router, and clients connect via the same name as before.
+
+- **Centralized registries.** An on-chain record cannot be revoked, because there is no intermediary.
+
+### Privacy considerations
+
+Names do not:
+
+- **Identify users.** There is no user directory, no requirement to register a name, and nothing links a name to the people who connect to it.
+
+- **Put communication on the chain.** The blockchain stores only the mapping from a name to links and optional public profile fields. Messages, membership, and channel content are never stored on the blockchain.
+
+- **Certify identity.** A verified name proves that the name's owner controls the address it points to - not who the owner is. It is the same trust model as a domain name.
+
+- **Replace links.** Links remain the primary and the more private connection mechanism, since resolving a name reveals interest in it to one resolver operator. Names are for public entities that choose to be contactable more easily.
+
+
+## Architecture
+
+### Names and records
+
+Names are lowercase labels of ASCII letters, digits, and single hyphens, forming domains under the `.simplex` top-level name (`example.simplex`, `my-channel.simplex`), with `.simplex` implied when omitted for channels: `#example` is interpreted as `#example.simplex`. The restricted alphabet prevents homograph attacks: visually identical names from mixed scripts cannot exist as distinct records.
+
+A name's on-chain record stores:
+
+- **Channel links and contact links** - each an ordered list, primary first. Multiple links give redundancy across SMP routers: clients try them in order, so the name remains usable if one router becomes unavailable. Client support for this redundancy is planned for the `.simplex` namespace launch.
+- **Optional profile fields** - a display name, website, location.
+- **Optional donation addresses** (Monero, Bitcoin, Ethereum, etc.) that apps can show to channel subscribers.
+
+Registration is a two-transaction commit-reveal process from the owner's wallet: the first transaction records only a hash, so an observer of the pending registration cannot see the name and front-run it; the second transaction reveals the name and completes the registration. The name is held as an ordinary token in the owner's wallet and is renewable and transferable. Subnames are created by the name's owner, are transferred together with the name, and cannot be separately sold - the same ownership model as DNS subdomains.
+
+### Resolution
+
+Connecting by name is two independent resolutions:
+
+1. **Name to link.** The client queries the on-chain record through the SimpleX network (next section) and obtains the channel or contact link.
+
+2. **Link to connection.** The link resolves through the existing SimpleX short-link protocol: the client retrieves the link's immutable data - cryptographically bound to the link's owner keys - and the entity's profile, and connects.
+
+The second step is unchanged from connecting by link. A name adds discoverability on top of the link protocol; it does not weaken the link's own verification, and everything a client checks when joining by link is still checked when joining by name.
+
+### Private decentralized RPC layer
+
+Reading blockchain state normally requires querying an RPC service, and in practice almost all applications - including wallets and name services - use a handful of centralized API providers. Those providers see every query, the account it concerns, and the querier's IP address, and can censor or falsify responses. Resolving names through such a provider would reveal every lookup and the client's IP address to a third party.
+
+SimpleX resolves names through the network itself. Operators can enable a *names role* on their SMP routers: a names router runs its own resolver process and its own Ethereum node, holding a full copy of the relevant chain state - operators must not share this backend with other operators. The lookup is a protocol command sent as ordinary SimpleX traffic:
+
+1. The client selects a names router among its configured servers and sends the lookup *through an SMP proxy operated by a different operator*, encrypted so the proxy cannot read it.
+2. The proxy forwards the lookup without access to its content; the names router responds from its local chain state.
+
+```mermaid
+sequenceDiagram
+    participant C as Client
+    participant P as SMP proxy<br/>(operator A)
+    participant N as Names router<br/>(operator B)
+    participant E as Ethereum node<br/>(operator B, local)
+
+    C->>P: lookup, encrypted for the names router
+    note over P: sees the client,<br/>not the name
+    P->>N: forwarded lookup
+    note over N: sees the name,<br/>not the client
+    N->>E: read name record (eth_call)
+    E-->>N: name record
+    N-->>P: response, encrypted for the client
+    P-->>C: name record: channel and contact links
+```
+
+The result is a knowledge split with no single observer: the proxy sees which client communicates with a names router, but not the name; the names router sees the name, but not which client sent the query - no client address, session, or identity. A passive network observer sees fixed-size encrypted blocks indistinguishable from other traffic. Clients also keep the set of parties that see a lookup minimal: a query is sent to one names router, and after an authoritative response the client does not repeat the name to other servers.
+
+This layer is not specific to names. Private access to blockchain state via independent operators is a network capability that can be used in other contexts in the future.
+
+### Claiming and verification
+
+A name is trustworthy when:
+
+1. **The on-chain record points to the link.** Only the name owner's wallet key can set this.
+2. **The link's profile claims the name.** Only the link owner's keys can publish this, and the claim is signed by the link's owner key, binding it to that specific link.
+
+For name resolution to succeed, SimpleX clients require both to be true. This mutual binding prevents abuse, such as:
+
+- Registering a name that points to someone else's address. The profile does not claim the name, so clients refuse to connect to it.
+- Claiming a name in a profile without owning it. The on-chain record does not point to that profile's address, so the claim fails verification.
+
+Apps display the outcome next to the name - verified (the record and the claim match), failed, or not yet verified - and can re-verify on demand or automatically. Verification is a fresh resolution through the private RPC layer, so it reflects the current on-chain state.
+
+Names are used only to establish connections, not to deliver messages. Once connected, a contact or channel subscription is an ordinary SimpleX connection, independent of the name. A name expiring or being transferred affects future connections only; existing conversations and subscriptions are not affected.
+
+
+## Differences from ENS
+
+The on-chain layer is the SimpleX Name Service (SNS), a fork of the [Ethereum Name Service](https://ens.domains) (ENS). ENS is the most widely used decentralized naming system, and SNS retains its core design: the registry and resolver contracts, commit-reveal registration, and expiry-based ownership.
+
+Each top-level name (`.testing`, `.simplex`) is an independent deployment of the same contracts:
+
+```mermaid
+flowchart TD
+    CT["Controller<br/>commit-reveal registration"]
+    RG["Registrar<br/>name tokens, on-chain name index"]
+    PR["Resolver<br/>simplex.contact / simplex.channel records"]
+    R["Registry<br/>owner and resolver of every name"]
+    MR["Metadata renderer<br/>token metadata as on-chain JSON + SVG"]
+    SR["Subname registrar<br/>creates and indexes subnames"]
+
+    CT -->|registers names| RG
+    CT -->|writes records| PR
+    RG -->|sets name ownership| R
+    RG -->|renders tokens| MR
+    SR -->|owns subname nodes| R
+```
+
+ENS, however, is not fully decentralized in use. Its applications depend on two off-chain services: an indexer (the subgraph) for queries such as listing the names held by an address (without it the ENS app is unusable), and a hosted metadata service to render name tokens in wallets. SNS removes both dependencies, and simplifies the ownership model:
+
+1. **No indexer.** The SNS contracts index names on-chain: reverse lookup from an address to the names it holds, from a token to its plaintext label, and from a name to its subnames are all direct contract reads. Every view in the SNS web app (currently, the app for test names is https://testing-names.simplex.chat) - the list of owned names, their subnames, and each name's records - is served by plain `eth_call`s against an Ethereum RPC.
+
+2. **Fully on-chain tokens.** A name's token metadata and image are generated by the contract as inline JSON and SVG. There is no metadata server; wallets render the name from chain data alone.
+
+3. **No name wrapper, no separate subname ownership.** ENS's wrapper system lets subnames be split off and owned independently, at the cost of a second token standard and a complex permission system. SNS subnames are owned together with the name and are transferred with it (the DNS model), removing the need for the wrapper.
+
+Resolution also differs. ENS names are resolved by applications through their RPC providers, so lookups are as centralized and observable as the provider. SNS records are read through the private RPC layer described above: many independent operators hold the chain state, and no single party sees who resolves which name.
+
+The result is a naming system with no off-chain services: registration, ownership, enumeration, rendering, and resolution are all either on-chain or served by the SimpleX network itself.
+
+The current implementation uses a web app for registration, which accesses the chain via a centralized RPC provider. We plan to add name purchases to the SimpleX apps, using the same decentralized blockchain access that is already used for name resolution.
+
+
+## Security
+
+### Design objectives
+
+1. **Non-custodial.** Only the holder of the name's key can change or transfer the record; there is no registrar, operator, or intermediary with override authority.
+2. **No infrastructure censorship.** A name does not depend on any single router: the links it points to can be replaced without changing the name, and resolution uses chain state held by many independent operators.
+3. **Impersonation resistance.** A name is shown as verified only when the on-chain record and the signed claim in the link's profile match.
+4. **Lookup privacy.** No single party observes both the user and the name being resolved.
+5. **Availability.** A record can list multiple links across routers, and any names-capable router of the user's choosing can respond to a lookup.
+
+### Threat model
+
+This threat model assumes the [SimpleX network threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/security.md) and the [channels threat model](https://simplex.chat/docs/protocol/channels-overview.md#threat-model), and addresses the naming layer.
+
+**A compromised names router (or its chain backend)**
+
+*can:*
+
+- Deny that a name exists, or serve a stale record, to the clients that query it. Detectable by resolving through a different operator's router.
+- Serve a false record - effective only against a client that queries this router *and* only if the false record's target cooperates by claiming the name, since the claim check runs against the attacker-supplied record. Resolver agreement across operators ([future work](#future-work)) makes this require collusion of the queried operators.
+- Observe which names are looked up, and how often.
+
+*cannot:*
+
+- Learn who is looking up a name - it never sees the client's address, session, or identity.
+- Alter the on-chain record, or affect clients resolving through other routers.
+- Affect existing connections - they do not depend on names.
+
+**An SMP proxy forwarding lookups**
+
+*can:*
+
+- See that a client communicates with a names router (which is an ordinary SMP router).
+
+*cannot:*
+
+- See that a request forwarded to a destination router is a name resolution request.
+- See the name being looked up, or the response - both are encrypted between client and names router.
+
+**An impersonator**
+
+*can:*
+
+- Register a confusingly similar name. The restricted alphabet keeps such names visibly different - homographs are not possible.
+
+*cannot:*
+
+- Register a visually identical variant of an existing name using other scripts or invisible characters.
+- Achieve verified status for a name pointing to someone else's address, or for an address whose name points elsewhere.
+
+**Compromise of the owner's wallet key**
+
+An attacker holding the registration key can repoint or transfer the name. New lookups then resolve to the attacker's links; the owner's profile claim no longer matches the record, so clients verifying the owner's profile see a failure. Existing connections are unaffected. Protecting the registration key is the owner's responsibility, the same as protecting the channel's own keys. An expired name that is not renewed can also be registered by someone else, so the key must be backed up and the name renewed on time.
+
+**A passive network observer**
+
+*can:*
+
+- See SimpleX traffic between clients and routers.
+
+*cannot:*
+
+- Distinguish name lookups from any other traffic, or learn which names anyone resolves. Inherited from SMP transport.
+
+### Current gaps
+
+1. **Single-resolver lookups.** A client currently accepts the response of one names router per lookup. Cross-checking two operators' resolvers is designed but not implemented - see below.
+2. **No state proofs.** The names router is trusted to report chain state correctly; responses do not yet include proofs verifiable against a chain header.
+3. **Self-hosted routers.** All pre-configured routers support name resolution, but most self-hosted routers do not support it yet. Name resolution requires at least one configured server with the names role.
+
+
+## Future work
+
+- **Two-resolver agreement.** Resolve each name through two independent operators via two different proxies and compare the responses: a match is trusted; a mismatch is shown as a warning and the record is not used. This removes the single-resolver trust noted above and makes record substitution require cross-operator collusion.
+
+- **State proofs.** Responses including Merkle proofs of Ethereum state, verified by the client - removing the need to trust the resolver, with or without agreement.
+
+- **Main namespace launch.** The `.testing` namespace is deployed for early adopters; the `.simplex` namespace launches after the testing period.
+
+- **Registration via an app.** Registration currently requires an on-chain transaction from a wallet.
+
+- **DNS-based names.** The client already parses arbitrary domains (`example.com`) as web links. In the future, it will be possible to register owned domains in the SNS contract to use them as channel and contact names (`#example.com` and `@example.com`).
+
+
+## Conclusion
+
+SimpleX names give channels and businesses memorable addresses that do not depend on any single server and cannot be revoked by a platform or registrar. Resolution runs through the SimpleX network, so no party observes who looks up which name. The naming system is fully decentralized on-chain, with no indexer or metadata service, and access to it is private, with no RPC provider observing requests. Names are optional and used only by public entities; private communication in SimpleX remains identifier-free.
+
+---
+
+Source: https://simplex.chat/docs/protocol/channels-overview.md
+
+Revision 1, 2026-04-28
+
+# SimpleX Channels: stateful information delivery and management
+
+## Table of contents
+
+- [Introduction](#introduction)
+  - [What are SimpleX Channels](#what-are-simplex-channels)
+  - [Channels as transport layer](#channels-as-transport-layer)
+  - [Content visibility and participant privacy](#content-visibility-and-participant-privacy)
+  - [In comparison](#in-comparison)
+  - [Non-goals](#non-goals)
+- [Architecture](#architecture)
+  - [State and distribution](#state-and-distribution)
+  - [Identity and ownership](#identity-and-ownership)
+  - [Governance](#governance)
+  - [Roles](#roles)
+- [Cryptographic primitives](#cryptographic-primitives)
+- [Security](#security)
+  - [Design objectives](#design-objectives)
+  - [Signing scope: roster only, content optional](#signing-scope-roster-only-content-optional)
+  - [Threat model](#threat-model)
+  - [Current gaps](#current-gaps)
+- [Future work](#future-work)
+  - [Stateful access and history navigation](#stateful-access-and-history-navigation)
+  - [Transcript integrity](#transcript-integrity)
+  - [End-to-end encrypted side conversations](#end-to-end-encrypted-side-conversations)
+  - [Relay addition and removal](#relay-addition-and-removal)
+  - [Governance evolution](#governance-evolution)
+  - [Pre-moderation](#pre-moderation)
+  - [Scheduled delivery](#scheduled-delivery)
+  - [Link preview proxying](#link-preview-proxying)
+- [Conclusion](#conclusion)
+
+
+## Introduction
+
+The SimpleX network provides private point-to-point communication without user or endpoint identifiers, but most speech that matters is public. Every existing platform that distributes content at scale identifies both publishers and their audiences to the operator - none protect participation privacy. SimpleX Chat supported peer-to-peer groups, but they cannot scale to large audiences. SimpleX Channels close this gap.
+
+### What are SimpleX Channels
+
+SimpleX Channels are a stateful information delivery and management layer built on the [SimpleX network](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md). SMP queues provide stateless, unidirectional packet delivery between two endpoints. Channels add persistence, state, and scalable distribution - enabling one-to-many publishing with cryptographic identity independent of infrastructure operators.
+
+[SimpleX Chat](https://simplex.chat) is the first application, presenting channels as a broadcast publication model where owners publish and subscribers read, react, and comment. But channels are not limited to this use case - they are a general-purpose layer for distributing and managing stateful information (feeds, telemetry, automated pipelines, coordination services, social media). This document describes channels as a transport mechanism - the same mechanism will also be used for large groups, communities, wikis, forums, and other social media primitives.
+
+The critical difference from conventional publish-subscribe systems is that channel identity and governance are controlled cryptographically by the channel owners, not by the infrastructure operators. Relays - SimpleX network clients that forward and optionally cache channel content - can be added, removed, and replaced without changing the channel's identity, address, content, or cryptographic trust chain. A channel's relationship with its relays is transient; its identity is permanent. The authoritative record of content is hosted on channel owners' devices; relays perform transmission and caching similar to CDN infrastructure.
+
+Channel owners hold full control of the channel - its identity, content, governance rules, and membership - through self-custody of cryptographic keys. No infrastructure operator, relay provider, or third party can control or alter a channel without the owner's keys. Blockchain systems achieve a related property for financial assets - no third party can control holdings - through network-wide consensus. Channels achieve it through local authority and cryptographic signatures, without global consensus or a public ledger. Unlike blockchain state, channel state is mutable by the owner and not publicly verifiable by third parties.
+
+### Channels as transport layer
+
+The SimpleX network has three transport layers, each built on the one below:
+
+1. **SMP** ([SimpleX Messaging Protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/simplex-messaging.md)) - stateless, unidirectional packet delivery between two endpoints through SMP routers. Provides fixed-size blocks, 2-node onion routing, and transport metadata protection.
+
+2. **SimpleX agents** ([agent protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/agent-protocol.md)) - bidirectional, redundant connections between endpoints, with end-to-end post-quantum double ratchet encryption. The [SimpleX Chat Protocol](https://simplex.chat/docs/protocol/simplex-chat.md) runs on top of this layer, providing direct messaging, group communication, and metadata delivery for file transfers via [XFTP protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md).
+
+3. **Channels** - stateful, one-to-many information delivery and management with cryptographic ownership and programmable governance. This layer runs on top of chat and agent layer 2, and it is described in this document.
+
+No network-wide user profile identifiers exist at any of these layers. Just as SMP enables private messaging by providing transport without user identifiers, channels enable public communication while preserving participation privacy at the distribution layer.
+
+Channel relays are themselves SimpleX clients in the SMP network, connecting to SMP routers using the same protocol, the same 2-node onion routing, and the same fixed-size transport blocks as any other endpoint. Even though the SMP network can distinguish a relay from a person's phone by its transport patterns, it prevents relays from learning anything about other network endpoints. In the case of SimpleX Chat, any CLI client can act as a chat relay without modifications.
+
+Channels therefore inherit all of SMP's transport privacy properties:
+
+- **Relays cannot observe subscriber network addresses.** The relay sees SMP queue addresses, not IP addresses or network sessions. The subscriber's IP is known only to their SMP router, which cannot see the message content (encrypted at the agent layer) or the IP addresses of whoever sends messages.
+
+- **SMP routers cannot see channel content.** Messages between relay and subscriber are end-to-end encrypted. The SMP router forwards fixed-size encrypted blocks without knowing whether they carry channel messages, direct messages, or anything else.
+
+- **Participation in multiple channels is unlinkable.** Each channel connection uses independent SMP queues with separate cryptographic credentials. Because of packet-level anonymity in 2-node routing, even if a subscriber uses the same SMP routers for all channels, the sending relays cannot determine this without collusion with those routers. Clients choose independently operated routers by default.
+
+No single point in the system sees both content and network identity. SMP routers see network addresses but not content, and no single SMP router can see which endpoints are communicating because clients choose independently operated routers. Relays see content but not network addresses.
+
+### Content visibility and participant privacy
+
+Any channel joinable via a public link, whether encrypted or not, must be considered completely public - the cost of joining through automated means has collapsed with large language models and is approaching zero. End-to-end encrypting such content provides no privacy; it only undermines users' security by creating false expectations and increases infrastructure operators' risks by making them unable to see what they deliver. Private channels with encrypted content are a separate use case discussed in [Future work](#end-to-end-encrypted-side-conversations).
+
+Content of public channels is therefore not end-to-end encrypted between owner and subscriber. Relays can read the messages they forward. Relay operators cannot undetectably alter channel content when multiple relays serve the channel, and cannot alter signed content at all - the authoritative state is held by owners. That each channel can use multiple chat relays provides both technical reliability and censorship resistance against any relay-specific content policies.
+
+The achievable privacy property for public communication is participation privacy - protecting who reads and writes content. The SMP transport carries no user identifiers, and relays are ordinary SMP clients, so subscribers connect without revealing their identity, network address, or any information that persists across channels. If an adversary joins a SimpleX channel, they see everything that is sent, but cannot determine who sent it or link any participant to anything outside the channel.
+
+Other systems make the opposite choice: content encryption in exchange for participant identification. For groups and channels joinable via public links this is the opposite of what is needed - the content encryption is meaningless (anyone can join and read), while the participant identification is the security threat.
+
+### In comparison
+
+**Telegram channels** - the operator controls channel identity (usernames are revocable), has full access to both content and participant identity. Channels cannot exist without Telegram's permission.
+
+**Nostr relays** - a single persistent key is used for publishing, following, and identity. Relays see content, the user's key, and their IP address. All posts and follow lists are signed and non-repudiable, linked to the same key - making both publishing and reading activity traceable and undeniable.
+
+**Signal groups** - content is end-to-end encrypted, but the operator manages group state and can observe the membership graph. Groups are capped at 1,000 members with no concept of a channel.
+
+**Matrix rooms** - server operators see room membership and metadata. Room identity is bound to the creating server's domain - if the server disappears, the room identity is lost.
+
+**Mastodon / ActivityPub** - publisher identity is bound to a server domain - if the server disappears, the identity is lost. Server operators see all content and all follower relationships. No encryption or privacy of any kind.
+
+| Property | Telegram | Nostr | Signal | Matrix | Mastodon | **SimpleX** |
+|---|---|---|---|---|---|---|
+| Content visible to operator | Yes | Yes | No | Configurable | Yes | **Yes** |
+| Participant identity visible to operator | Yes | Yes | Yes | Yes | Yes | **No** |
+| Channel identity independent of infrastructure | No | Yes | No | No | No | **Yes** |
+| Sovereign ownership (no 3rd party can seize) | No | Yes | No | No | No | **Yes** |
+| Programmable governance | No | No | No | No | No | **Planned** |
+| Cryptographic content deniability | No | No | Yes | Yes | No | **Yes (default)** |
+| Scalable one-to-many delivery | Yes | Yes | No | Limited | Yes | **Yes** |
+
+### Non-goals
+
+Channels do not attempt to:
+
+- **Encrypt public content from relay operators.** See [Content visibility and participant privacy](#content-visibility-and-participant-privacy).
+- **Assign persistent identities to participants.** There are no usernames, public keys, or any identifiers that persist across channels or link activity across contexts.
+- **Require network-wide consensus.** Channel state is authoritative on owner devices. The network does not validate channel transactions.
+- **Guarantee immutability of content.** Channel state is fully controlled and mutable by owners, unlike blockchain state, which is immutable by design.
+
+## Architecture
+
+The introduction established what channels provide and why. This section describes how: where state lives, how identity and ownership work, how governance evolves, and what each participant does.
+
+### State and distribution
+
+The authoritative record of a channel - content, member roster, profile, cryptographic keys, governance rules - is held by channel owners on their own devices, not on relays, not on any server, and not on any shared ledger. Relays hold transient copies for distribution and optional caching, analogous to CDN edge nodes: the origin holds the truth, CDN nodes come and go. Consensus is only required between channel owners, not across the entire network.
+
+```
+                     ┌──────────┐
+                     │  Owner   │  <- authoritative state
+                     └────┬─────┘
+                          │
+              ┌───────────┼───────────┐
+              │           │           │
+         ┌────▼───┐  ┌────▼───┐  ┌────▼───┐
+         │Relay A │  │Relay B │  │Relay C │  <- cache / distribution
+         └────┬───┘  └────┬───┘  └────┬───┘
+              │           │           │
+        ┌─────┼─────┐    ...    ┌─────┼─────┐
+        │     │     │           │     │     │
+       S1    S2    S3          S7    S8    S9   <- received copies
+```
+
+Content originates on the owner's device and flows through relays to subscribers. Each relay independently forwards to all of its subscribers. Subscribers do not connect to owners or to each other - this provides better scalability than peer-to-peer SimpleX groups, where adding a member requires N new connections. When multiple relays serve the same channel, subscribers deduplicate at the client level.
+
+**Failure modes:**
+
+- **Loss of a relay is loss of a cache node, not loss of data.** The owner can send the same content through a replacement relay.
+
+- **Loss of all owner devices is the catastrophic event** - relay caches become orphaned and the channel's private keys are gone. Multiple owners and backups mitigate this risk.
+
+- **Disagreements between relays are resolved by the origin.** The owner's version is authoritative, settling cache inconsistency through any reachable relay.
+
+Subscribers hold their own received copies. Signed messages are independently verifiable without consulting the relay or owner. Unsigned content depends on cross-relay consistency or future transcript integrity mechanisms.
+
+### Identity and ownership
+
+A channel's identity is the SHA-256 hash of the genesis root public key, computed at creation time and never changed - even if relays are added, removed, or the channel link is rotated. It is self-authenticating: derived from a key pair that only the channel creator held. It is embedded in the channel's link, distributed in the profile to all members, and used as a binding prefix in all signed messages.
+
+Subscribers validate that the identity in the link matches the identity in the profile, preventing link substitution. Profile updates that attempt to change the identity are rejected. Full validation that the identity equals the hash of the root key is deferred: if current clients enforced this check, they would reject future rotated links as invalid. The identity is correctly managed today; validation will be enforced with the key rotation protocol. See the [group identity binding RFC](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2026-03-28-group-identity-binding.md).
+
+The root key does not sign messages directly. Instead, it authorizes owner keys through a signed chain. At creation, the owner generates a root key pair and a separate member key pair for signing. The member key is published as an authorization entry signed by the root key. New owners can be added by any previously authorized owner signing a new entry. Anyone retrieving the channel link can verify this chain without network access.
+
+The root key is a bootstrap key - it certifies owners, then need not be used again. All owners are cryptographically indistinguishable to subscribers (they all have equally valid authorization chains), which - provided multiple owners were signed by the root key - conceals the creator's identity.
+
+The channel link is the out-of-band trust anchor - relays and SMP routers cannot modify link content. All members announce their signing keys on joining. Owner keys are verifiable against the link. Role changes (promoting members to admin, moderator) are signed by owners at the protocol level.
+
+A planned extension will record role changes as a linearly ordered signed roster log with consistent sequencing across all owners, relays, and subscribers. This linearization prevents ambiguous roster states from concurrent unordered changes, and creates a verifiable chain of trust from the channel link through owners to all elevated roles. Out-of-band key verification for non-owner members will further extend this to E2E encrypted conversations.
+
+### Governance
+
+"Management" in "information delivery and management" refers not only to managing content but to managing the channel itself - who can make decisions, and how.
+
+The low-level protocol supports multiple owners from the initial release. The application-level governance model evolves through a planned progression:
+
+**Current (v6.5): Single owner.** One owner controls the channel. All administrative actions (profile changes, roster modifications, relay management) are decided by this single owner. The protocol-level owners chain supports verification of multiple entries, but the application creates and manages only one.
+
+**Near-term (v7): Multiple owners, any-owner-decides.** Multiple owners share control of the channel. Any owner can independently make any administrative decision - add or remove members, change the profile, manage relays. This is the most common decision-making model in practice (equivalent to "all admins are equal" in most online platforms). No coordination between owners is required for any action.
+
+**Future: Multisig and programmable governance.** Further stages include M-of-N multisig for administrative actions and, eventually, programmable governance rules defined as code in the channel's definition. The protocol must support these without prescribing a specific governance model.
+
+### Roles
+
+- **Owners** create the channel, hold the authoritative state and private keys on their devices, publish content, and manage the member roster. Owners sign administrative messages and optionally content messages. A channel must have at least one owner.
+
+- **Relays** receive content from owners and members with posting rights, optionally cache it, and forward it to subscribers. They accept new subscriber connections and introduce them to the channel owners. Relays cannot author messages. A channel must have at least one active relay. Relays are ordinary SimpleX clients - a relay can be operated by anyone (a channel operator, a third-party service provider, or a self-hosted instance) and each creates its own contact address link, bound to the channel's identity. The relay's relationship with the channel is transient - owners can add and remove relays without changing the channel's identity.
+
+- **Subscribers** connect to relays and receive content. They cannot send messages by default, but can be given posting rights.
+
+Additional roles (moderator, admin, member, author) exist in the hierarchy and are inherited from the group protocol. The owner-signed roster tracks the promoted set - members, moderators, and admins; subscribers are observers until an owner promotes them.
+
+For protocol-level detail - wire formats, message types, signing and verification mechanics, delivery pipeline - see [SimpleX Channels Protocol](https://simplex.chat/docs/protocol/channels-protocol.md).
+
+
+## Cryptographic primitives
+
+- **Ed25519** - channel identity (root key pair), owner authorization chain, and message signing. The signature binding prefix includes the channel's entity ID and the sender's member ID, preventing cross-channel replay.
+
+- **SHA-256** - derives the channel's entity ID from the genesis root public key. Immutable, serves as the channel's permanent identity.
+
+- **Double ratchet with post-quantum KEM** (inherited from [SimpleX agent layer](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/agent-protocol.md)) - end-to-end encryption for all SMP transport. Not channel-specific - channels inherit it by being built on the agent layer. Future E2E side conversations (support scope, member DMs, private channels) will use the same mechanism.
+
+Content messages are not signed by default to preserve cryptographic deniability - see [Signing scope](#signing-scope-roster-only-content-optional). Owners may opt into signing all content in a future release.
+
+
+## Security
+
+This section examines what the architectural properties protect against, where they hold, and where gaps remain.
+
+### Design objectives
+
+The channel protocol is designed to achieve the following security objectives:
+
+1. **Stable message delivery** between channel participants, resilient to individual relay failures.
+2. **No possibility for a relay to substitute the channel** - the channel's identity is cryptographically bound to the link and profile controlled by channel owners.
+3. **No possibility for a relay to impersonate an owner** - administrative messages require valid signatures.
+4. **Prevention of relay-initiated roster manipulation** - member removal, role changes, and other roster modifications require valid owner signatures.
+5. **Relay transience** - the owner can add and remove relays, including the last relay, without permanently losing the channel. Subscribers can restore connectivity by retrieving updated link data.
+6. **Sender anonymity within multi-owner channels** - owners can publish as the channel, hiding which specific owner authored a message from subscribers.
+7. **Participant privacy** - relay operators cannot determine subscriber identity or network address, and subscribers cannot determine each other's identity. This is inherited from the SMP transport layer.
+
+### Signing scope: roster only, content optional
+
+By default, only roster-modifying and administrative messages are signed. Content messages are not signed. Two reasons:
+
+1. **Cryptographic deniability.** Signing creates non-repudiable proof of authorship verifiable by any third party. Without signatures, no such proof exists - a relay could have fabricated any unsigned message.
+
+2. **Proportional defense.** Changes to roster, channel profile, and permissions can be disruptive and irreversible - they must be authenticated at processing time. Content manipulation is detectable post-hoc through cross-relay consistency, and the authoritative record on the owner's device is unaffected.
+
+Owners will be able to opt into signing content on a per-channel or per-message basis - some publishers want non-repudiable authorship, others prefer deniability.
+
+### Threat model
+
+This threat model assumes the [SimpleX network threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/security.md) and addresses threats specific to the channel layer.
+
+**A single compromised relay**
+
+*can:*
+
+- Substitute unsigned content or selectively drop messages for its subscribers. Detectable by subscribers connected to other relays - the owner's version is authoritative. TODO: difference detection not yet implemented.
+- Selectively target specific subscribers while delivering correctly to others.
+- Ignore the "message from channel" directive, revealing which owner sent a message. Detectable out-of-band.
+- Fabricate or hide subscriber connections, inflating or deflating counts. Detectable if subscribers are connected to other relays.
+
+*cannot:*
+
+- Undetectably substitute content - subscribers on honest relays receive the original.
+- Alter the channel's authoritative state on the owner's device.
+- Substitute the channel profile or impersonate an owner - these require valid signatures.
+- Replay an old roster or role change to re-elevate a removed or demoted member for existing subscribers - they reject anything older than the roster version they applied (a new joiner with no prior roster can still be served an old one, until it syncs from another relay).
+- Redirect subscribers to a different channel - the entity ID is validated across link and profile.
+- Determine subscriber identity or network address - inherited from SMP transport.
+- Correlate subscriber participation across channels - each connection uses independent SMP queues. The subscriber chooses their SMP router independently, so collusion between a relay and the relay's SMP router does not compromise connections through a different router.
+
+**All relays compromised and colluding**
+
+*can:*
+
+- Undetectably substitute unsigned content for all subscribers, unless owners sign content messages.
+- Prevent delivery of any messages, including signed ones (signing prevents substitution, not dropping).
+- Fabricate or hide subscriber connections undetectably.
+
+*cannot:*
+
+- Forge signed administrative messages or substitute the channel profile.
+- Alter the authoritative state on the owner's device.
+
+**Compromise of owner keys**
+
+An attacker who obtains the root private key or an owner's member private key (through device compromise, backup theft, or coercion) can impersonate the owner and sign arbitrary administrative messages. This is a different threat from key loss - the channel continues operating, but under adversarial control. Mitigation depends on owner-side operational security and future multisig governance. For the threat model of the channel link itself (the trust anchor), see the [short links for groups RFC](https://github.com/simplex-chat/simplexmq/blob/stable/rfcs/2025-04-04-short-links-for-groups.md).
+
+**Loss of all owner devices**
+
+The channel can have no new content, no administrative updates, no new owners. Relay caches continue delivering existing content but cannot be refreshed, and will eventually expire in the absence of the owner connection. Multiple owners and key backups mitigate this risk.
+
+**A subscriber**
+
+*can:*
+
+- See all public content, by design.
+- Join multiple times with different profiles, inflating counts.
+
+*cannot:*
+
+- Identify other subscribers, send messages to the channel (unless given posting rights), or forge messages of the owner or other subscribers.
+
+**A passive network observer**
+
+*can:*
+
+- Observe communication with an SMP router, but not whether it is channel-related.
+
+*cannot:*
+
+- Determine which channel a subscriber uses, correlate channel activity with other SimpleX activity, or identify a relay as distinct from an ordinary user, other than by traffic volume. Inherited from SMP transport.
+
+### Current gaps
+
+1. **Cross-relay consistency detection.** Duplicate messages are silently deduplicated without hash comparison. Designed but not implemented.
+2. **Link entity ID validation.** Deferred to a future version with key rotation. See [group identity binding RFC](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/rfcs/2026-03-28-group-identity-binding.md).
+3. **Multi-relay UX.** Protocol supports multiple relays per subscriber; no UX for monitoring relay-level delivery health. It will be added in v6.5.x.
+
+
+## Future work
+
+### Stateful access and history navigation
+
+Currently, relays send recent cached history on join but do not support navigation or search. Planned: history pagination by timestamp or message ID, remote search against relay caches, and selective retrieval of specific message ranges. Relay operators can differentiate on cache depth and search capabilities.
+
+### Transcript integrity
+
+- **Opt-in content signing.** Per-channel or per-message choice to sign content, making it non-repudiable. This will be released in SimpleX Chat v7.
+- **Subscriber transcript acknowledgment.** Subscribers periodically sign a digest of received history ("I've seen it" rather than "I've authored it"), enabling detection of relay manipulation through diverging digests.
+- **Merkle tree signing.** Owner periodically publishes a signed Merkle root. Subscribers verify their copies against the owner's authoritative record.
+
+### End-to-end encrypted side conversations
+
+- **E2E encrypted support scope** between subscriber and moderator/owner.
+- **E2E encrypted DMs between members** where channel settings permit, using standard SimpleX connection establishment.
+- **Private channels** where the entire content stream is encrypted to authorized subscribers. The relay becomes a conduit that sees neither content nor identity.
+
+### Relay addition and removal
+
+Dynamic relay addition with cache population from existing relays or owner. Relay removal with subscriber migration. Relay rotation with continuity - new relay connects before old relay is removed. It will be added in v6.5.x.
+
+### Governance evolution
+
+- **Multiple owners (v7):** concurrent administrative authority, any owner acts independently.
+- **Multisig:** M-of-N approval for administrative actions, with per-action quorums.
+- **Programmable governance:** rules defined as code in the channel definition.
+
+### Pre-moderation
+
+Subscriber messages reviewed by moderators before becoming visible to all subscribers.
+
+### Scheduled delivery
+
+Messages scheduled for future delivery, cached by relay until the scheduled time.
+
+### Link preview proxying
+
+The relay loads link previews on behalf of the sender - it already sees message content, so it learns nothing new, and unlike the sender its IP is not linked to any identity.
+
+
+## Conclusion
+
+SimpleX Channels enable a publisher to reach an unlimited audience without any infrastructure operator knowing who that audience is. No third party can seize the channel because owners hold the keys and the authoritative state on their own devices - relays only cache and forward. Owner signatures protect content integrity and the trust chain extends to all administrative roles. These properties require a network without participant identifiers - they cannot be added to a system that has them.
+
+---
+
+Source: https://simplex.chat/llms/agents.md
+
+# SimpleX for AI agents and developers
+
+SimpleX is a messaging network without user identifiers. A program connects to it the same way a person does: it holds its own keys, creates addresses it can share and delete, and needs no phone number, platform account or API key. The network does not distinguish a person from an agent, and no platform can suspend an agent's identity or see who it talks to.
+
+What you can build:
+
+- an assistant that its owner reaches privately from the SimpleX Chat app, on any device;
+- a support or search bot for many users, with an LLM or without one;
+- communication between agents with no platform in the middle;
+- moderation, broadcast and bridge bots for groups and channels.
+
+## Make a bot in five minutes
+
+### Node.js
+
+```sh
+npm i simplex-chat
+```
+
+```javascript
+(async () => {
+  const {bot} = await import("simplex-chat")
+  await bot.run({
+    profile: {displayName: "Squaring bot example", fullName: ""},
+    dbOpts: {type: "sqlite", filePrefix: "./squaring_bot"},
+    options: {
+      addressSettings: {welcomeMessage: "Send a number, I will square it."},
+    },
+    onMessage: async (ci, content, chat) => {
+      const n = +content.text
+      const reply = typeof n === "number" && !isNaN(n)
+                    ? `${n} * ${n} = ${n * n}`
+                    : `this is not a number`
+      await chat.apiSendTextReply(ci, reply)
+    }
+  })
+})()
+```
+
+On start, the bot creates its SimpleX address and prints it (`Bot address: ...`). Open this address in the SimpleX Chat app to talk to the bot. Library: [simplex-chat on npm](https://www.npmjs.com/package/simplex-chat), [source and examples](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-nodejs).
+
+### Python (3.11+)
+
+```sh
+pip install simplex-chat
+```
+
+```python
+import re
+from simplex_chat import Bot, BotProfile, Message, SqliteDb, TextMessage
+
+bot = Bot(
+    profile=BotProfile(display_name="Squaring bot"),
+    db=SqliteDb(file_prefix="./squaring_bot"),
+    welcome="Send me a number, I'll square it.",
+)
+
+@bot.on_message(content_type="text", text=re.compile(r"^-?\d+(\.\d+)?$"))
+async def square(msg: TextMessage) -> None:
+    n = float(msg.text or "0")
+    await msg.reply(f"{n} * {n} = {n * n}")
+
+@bot.on_message(content_type="text")
+async def fallback(msg: Message) -> None:
+    await msg.reply("Send me a number, like 7 or 3.14.")
+
+if __name__ == "__main__":
+    bot.run()
+```
+
+The bot logs its address on start. Library: [simplex-chat on PyPI](https://pypi.org/project/simplex-chat/), [source and examples](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-python).
+
+## Use the terminal client as an API server, from any language
+
+Install the terminal client on Linux or macOS:
+
+```sh
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+```
+
+Run it as a local WebSocket server:
+
+```sh
+simplex-chat -p 5225
+```
+
+Your program connects to `ws://localhost:5225` and sends JSON commands, for example to create a long-term address:
+
+```json
+{"corrId": "1", "cmd": "/address"}
+```
+
+Responses carry the same `corrId`; chat events, such as received messages, arrive as separate messages. The command strings are the same as in the app's chat console. The WebSocket API has no authentication and binds to localhost: run your program on the same machine, or put a TLS proxy with authentication in front of it.
+
+- [Bot API guide](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/README.md)
+- [Commands](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/COMMANDS.md)
+- [Events](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/EVENTS.md)
+- [Types](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/TYPES.md)
+- [Terminal client guide](https://simplex.chat/docs/cli.md)
+
+## Build the terminal client from source
+
+With Docker, on Linux:
+
+```sh
+git clone https://github.com/simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+DOCKER_BUILDKIT=1 docker build --output ~/.local/bin .
+```
+
+With GHC 9.6.3 and cabal 3.10.1.0 installed via [GHCup](https://www.haskell.org/ghcup/), on Linux:
+
+```sh
+git clone https://github.com/simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+apt-get update && apt-get install -y build-essential libgmp3-dev zlib1g-dev
+cp scripts/cabal.project.local.linux cabal.project.local
+cabal update
+cabal install simplex-chat
+```
+
+On macOS, install OpenSSL with `brew install openssl@3.0` and use `scripts/cabal.project.local.mac` instead. Full instructions: [terminal client guide](https://simplex.chat/docs/cli.md).
+
+## OpenClaw
+
+A community plugin connects [OpenClaw](https://github.com/openclaw/openclaw) to SimpleX through a locally running terminal client, so you can talk to your OpenClaw assistant from the SimpleX Chat app:
+
+```sh
+openclaw plugins install @dangoldbj/openclaw-simplex
+openclaw plugins enable openclaw-simplex
+```
+
+Source: [github.com/dangoldbj/openclaw-simplex](https://github.com/dangoldbj/openclaw-simplex).
+
+## Run your own servers
+
+- [SMP messaging server](https://simplex.chat/docs/server.md)
+- [XFTP file server](https://simplex.chat/docs/xftp-server.md)
+
+## Protocol specifications
+
+- [SimpleX network overview](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/overview-tjr.md)
+- [SimpleX Messaging Protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/simplex-messaging.md)
+- [Agent protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/agent-protocol.md)
+- [Post-quantum double ratchet](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/pqdr.md)
+- [Security model](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/security.md)
+- [XFTP file transfer protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/xftp.md)
+- [Chat protocol](https://simplex.chat/docs/protocol/simplex-chat.md)
+
+## Ask the SimpleX team
+
+In the SimpleX Chat app, open the "Ask SimpleX Team" chat, or connect via [simplex.chat/contact](https://simplex.chat/contact#/?v=2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion). A support bot answers first:
+
+- send `/team` to reach the team – not a bot; the team replies within 24 hours, or 48 hours at weekends;
+- send `/grok` for an instant answer from an AI assistant.
+
+---
+
+Source: https://simplex.chat/wefunder.md
+
+# SimpleX Chat equity crowdfunding on Wefunder
+
+SimpleX Chat is conducting an equity crowdfunding offering under Regulation Crowdfunding through Wefunder Portal LLC: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat). The offering terms are on Wefunder, including its AI-readable profile: [wefunder.com/simplex.chat.ai.txt](https://wefunder.com/simplex.chat.ai.txt).
+
+This page reproduces the memo from the Wefunder page, for AI assistants that cannot read Wefunder.
+
+## Memo
+
+For most of human history, conversations were private by default, and the communities people built belonged to them. The internet made communication easier, but it also placed companies between people and the relationships they created. SimpleX exists to bring that privacy and ownership back to the people.
+
+### In short
+
+SimpleX is the first and the only messaging network without any user identifiers – no phone numbers or usernames, not even random numbers. No one, including the servers, can see who talks to whom.
+
+No paid marketing. Hundreds of community publications. Over 3 million downloads. About 600,000 monthly users. $650,000 user donations. Over 1,000 community servers. Three security audits by Trail of Bits, the last to be published.
+
+Why now? Accelerating surveillance and deplatforming, and the rise of AI agents may increase demand for identity-free messaging that no other network can provide.
+
+SimpleX is more than a messenger – it's an open platform others can build on. Developers already built moderation and AI bots, bridges, and other services. Every service may increase the value of the network and bring new people in.
+
+We plan to charge businesses and channels for public names, business messaging and paid servers beyond the free tier, while private messaging remains free.
+
+### Current perks for investors
+
+If you invest $500 or more, you will receive a free SimpleX public name for your channel or business – 8+ letters with $500+ investment, 7+ letters with $1,000+, and 6+ letters with $5,000+.
+
+The name will be registered for 5 years while early bird terms apply, and for 3 years after that.
+
+All investors receive free SimpleX supporter badges as perks. More details: [SimpleX Supporter Badges](https://simplex.chat/blog/20260919-simplex-supporter-badges.md).
+
+### Every other network can identify users
+
+For 150 years, all networks required user identifiers. From the telephone invented in the 19th century, to email services, social media, and messaging – using phone numbers, usernames, random IDs or public keys – before SimpleX Network, to be reachable, you had to be identifiable.
+
+#### Every other messenger knows who you talk to
+
+User identification gives networks power over users to surveil their private life, to sell their data, and to revoke access. Even encrypted platforms see who you talk to, when, and where. Pseudonyms don't help – your contacts are a fingerprint.
+
+And being identified puts your identity and data at risk of being used by criminals.
+
+#### Every other platform can censor users without due process
+
+Telegram blocked 44 million groups and channels in 2025 alone. YouTube creators lose channels and can't recover them even after winning in legal proceedings.
+
+Every platform that distributes content at scale identifies both the publisher and the audience – giving platform owners the power to censor public speech.
+
+Publishers and content creators build audiences on borrowed infrastructure. One policy change, and the audience that took years to build can be gone.
+
+The root cause of these problems is user identification. The solution is not better policies or stronger encryption with the same architecture – it is a different architecture, without user IDs.
+
+### We invented and built SimpleX Network without any user identifiers
+
+It uses no phone numbers, emails, or user accounts – to take power from the network and give it back to the users. The network runs on multiple independent operators – SimpleX Chat and Flux are preconfigured in the app, and anyone can run their own servers.
+
+And we built a free SimpleX Chat app, for mobile and desktop, that uses SimpleX Network to connect to other users.
+
+SimpleX Chat provides private messaging without any user IDs – it protects the users, because no one can see who they talk to. As one X user wrote: "As long as I don't invite anyone to a chat, nobody can find me – and that's the best part about it. That's how privacy works". And families tell us they use SimpleX Chat with their children, because they feel safe knowing no one can reach them.
+
+SimpleX Chat also enables public groups and channels, where owners fully control them, and nobody can take their work, because only the users hold the keys.
+
+Every conversation in SimpleX Chat has its own network address, removing the need for any user IDs on the network. There is no user data on the servers that could be breached or sold – all user data exists only on user devices.
+
+SimpleX software is open-source and based on open protocols. It was audited by Trail of Bits in 2022, 2024, and 2026 (will be published soon).
+
+### 600,000+ users – organic growth
+
+Over 600,000 people use SimpleX Chat every month – up roughly 70% in the last six months – and all of them found it without any paid marketing. Among them are security and cryptography experts – the hardest users to win over.
+
+200+ independent reviews, posts, and videos in 20+ languages ([simplex.chat/links](https://simplex.chat/links.md)).
+
+3 million people have downloaded the app.
+
+Users send over 20 million messages a day via pre-configured servers.
+
+Users have donated over $650,000 (including the donation from Vitalik Buterin), paying for something they could use for free.
+
+All of it was built on a total investment of just $1.7M.
+
+### SimpleX is a network, not just an app
+
+Not only the people who use SimpleX primarily for private messaging, but also four other kinds of participants came to the network:
+
+- Creators, with thousands of public groups and channels.
+- Businesses: 50+ support customers over SimpleX.
+- Developers: 19K+ GitHub stars, 1,400+ forks.
+- Operators: ~1,000 servers run by volunteers at their own cost, plus Flux and StormyCloud.
+
+Each user group makes the network more valuable to the rest – more users attract creators and businesses, creators attract servers and developers, more content and network utility attracts more users – driving organic growth.
+
+### Channels accelerate SimpleX Network growth
+
+Messaging grows person-by-person: whole social graphs have to move together, which is slow against widely used networks, such as WhatsApp or Telegram. Channels accelerate it – one creator who brings a channel to SimpleX can bring thousands of subscribers, some of whom would then create their own channels.
+
+Users have created over 12,500 scalable channels in the five months since they shipped. 500+ public groups and channels are in the curated directory, 30% of them are active daily. Telegram channels tried to migrate in 2024/25, before SimpleX channels could scale. All that growth happened without in-app discovery of groups and channels – we are planning to release it this year, to further accelerate the growth.
+
+Each channel can also be published on the open web – like [simplex.chat/news](https://simplex.chat/news). Search engines index these pages, and anyone can read them in a browser without installing the SimpleX Chat app, so a channel can reach more people than use the app, and some of them may install it.
+
+### Developers already bet on SimpleX success
+
+Developers have already started building on SimpleX Network, with some projects defining themselves as SimpleX-first – they run all communications of their applications over the SimpleX Network. They built moderation, swap, and AI bots, bridges (Telegram/Matterbridge), a public server registry, and the OpenClaw plugin. To enable their work, we provide the JavaScript and Python libraries, a customer-support bot for businesses, and binaries to self-host servers.
+
+Every service developers build on SimpleX Network may increase its value, and bring new users to SimpleX Chat. In 2027, we are planning to release secure chat widgets and activities – to accelerate community innovation, by allowing custom UI for bots and services right in the conversation.
+
+### Why SimpleX cannot be copied
+
+No other communication system combines participation privacy, sovereign ownership, infrastructure independence, and scalable one-to-many delivery:
+
+| Property | Telegram | Nostr | Signal | Matrix | Mastodon | **SimpleX** |
+|---|---|---|---|---|---|---|
+| Content visible to operator | Yes | Yes | No | Configurable | Yes | **Yes** |
+| Participant identity visible to operator | Yes | Yes | Yes | Yes | Yes | **No** |
+| Channel identity independent of infrastructure | No | Yes | No | No | No | **Yes** |
+| Sovereign ownership (no 3rd party can seize) | No | Yes | No | No | No | **Yes** |
+| Programmable governance | No | No | No | No | No | **Planned** |
+| Cryptographic content deniability | No | No | Yes | Yes | No | **Yes (default)** |
+| Scalable one-to-many delivery | Yes | Yes | No | Limited | Yes | **Yes** |
+
+Of these networks, only SimpleX can protect participants' privacy, because it would require other networks to remove user identifiers – not adding a feature to an existing system but designing a different one. That is hard for three reasons, each stopping a different kind of competitor.
+
+Technically. Other networks rely on user IDs to route messages between users. Signal, Session, Matrix, and Nostr cannot simply drop IDs – they would have to rebuild from scratch.
+
+Economically. Large platforms monetize user identifiers: Telegram and Meta earn from ads and data, and that requires linking every action and connection to a single user ID. Removing IDs would destroy their revenue model. A large company is highly unlikely to do that.
+
+Cold start. A new company could build a no-ID network from scratch. But a network needs users, creators, businesses, developers, and servers, all at the same time. A newcomer would have to achieve it from zero, while competing with the SimpleX Network.
+
+### Why now: three trends that may grow SimpleX
+
+Growing surveillance of private life. Big centralized platforms are keen to scan private messages to train their AI models, supported by proposed laws. More people would move to use private messaging that keeps no record of who they talk to.
+
+Accelerating deplatforming. More and more creators are removed from centralized platforms, without any due process. An audience built over years can disappear with one policy change. Affected or at risk content creators would use decentralized networks where they own their work.
+
+AI agents acting for people. A growing number of AI agents are beginning to handle logins and money on behalf of people. If a platform controls an agent's identity, the platform can shut the agent down or turn it against the person it works for. User-controlled IDs are a basic security for the agentic Internet, not a preference.
+
+All three trends increase the demand for identity-free messaging. No other existing network can provide it.
+
+### Revenue plan: free for users, channels & businesses pay
+
+Private messaging should remain free for the users. While additional storage and transfer capacity may be paid, charging users for features would erode the trust that helps the network grow organically. Instead, we plan to earn from the infrastructure and services that channels and businesses need. On average, users donated ~$1.24 each per year, which shows they are willing to pay before any paid features exist.
+
+#### Public network names
+
+Most users want to be reachable only by people they choose. But businesses, creators, and publishers need to be found, so they need a public name they control. Even with a public name, the network cannot see who they talk to.
+
+SimpleX public names are globally unique names for a public channel or business, paid yearly and controlled by the owner's key, so no one can seize it. The public test is already released; sales are planned in 3–6 months. Pricing is based on name length. SimpleX Chat plans to earn approximately 80-90% of namespace revenue. At an average expected price of $50 a year (to be confirmed) for a name, 10,000 registered names would cover our current $360,000 annual operating cost.
+
+If you invest $500 or more in this community round, you would receive a name as a perk, registered for 5 years during early bird terms and for 3 years after that, when the names launch.
+
+#### Business messaging
+
+We are developing a web widget that would add encrypted chat to any website with one line of code, allowing visitors to talk to the business in their browser without installing anything. It is built for privacy-first businesses and business sectors where anonymity is legally required: whistleblowing, ethics, HR, security, legal, sensitive customers, sources, and tip lines.
+
+50+ businesses use SimpleX Chat for support, and they would be the first customers. The proof-of-concept is done; planned in 6–9 months from closing the round, with an expected price of $20–100/month per business.
+
+It grows the network as well. Someone who talks to a few businesses is already using SimpleX without having installed it, and a QR code scan would bring those conversations into the app.
+
+#### Paid servers for big channels
+
+Big public channels that have grown beyond the free tier would pay for the servers that deliver their messages. The proof-of-concept is ready, planned within 12 months of closing the community round, with an expected price of $20–50/month, depending on the channel size. We plan that server operators would earn up to 65% of the revenue, several times their cost, and SimpleX Chat earns the rest.
+
+### An open network others can build on
+
+The network is open, and it would help if other developers built their own apps on it – one app cannot reach every audience, and many apps may grow the network faster than we could alone. A bigger network may also bring more users and revenue for SimpleX Chat.
+
+The SimpleX Network Consortium, an agreement between a non-profit SimpleX Network Foundation and SimpleX Chat, prevents any single company from controlling the network. The protocol and the right to use the SimpleX mark for the network are licensed to the foundation permanently, so that operators and users can trust that the network protocols and software remain available regardless of who owns the company.
+
+SimpleX Chat business is protected too: the company owns the app, the brand, mobile application store distribution, preset relay infrastructure, and will retain its revenue share from the infrastructure payments, a position protected by its veto power over Consortium decisions.
+
+### The goal: the universal private transport layer
+
+Every network before messaging converged to one protocol – telephony, email, the web. Messaging is the exception, because each app's experience can't reduce to a shared protocol. Once we add custom user experiences in the chat, SimpleX might become the network messaging converges on.
+
+The planned revenue above is the first layer. The same network and protocol can deliver: private messages, public channels, businesses, and traffic between AI agents. The optional directory and payment system would create revenue for the server operators and SimpleX Chat.
+
+AI agents are the next layer, and developers already build AI bots. The network does not distinguish between a person and an agent. Agents need exactly what SimpleX provides: an identity no platform controls, and communication no one can observe.
+
+The same public names and payment system can be used by any service on the network, not only messaging or channels, so the revenue may grow with everything built on it.
+
+### Why this team wins
+
+We have worked on publishing, messaging, protocol design, blockchains, and cryptography. We have built large-scale systems and open-source software that millions of systems and projects rely on.
+
+We believe that what SimpleX Network achieved comes from listening to users' criticism. Unlike most technology startups, we announce our plans in advance, and change them before they become products, saving time and resources to get to product-market fit.
+
+We are also fortunate to have great advisors. Some of them are: Moritz Angermann (IOHK, Haskell compiler core contributor), Bruce McCarthy (Product Culture founder), Tom Ritter (Tor, Mozilla, an expert in secure protocol design), and Nick Rogers (ex-CPTO of Stream, an expert in agentic products). Three of them invested in this round.
+
+### Invest in SimpleX Chat
+
+By investing in SimpleX Chat, you benefit from the company growth. You also help build the first network that protects private life because it has no user identifiers – a design decision that cannot be retrofitted into any existing network.
+
+We are building a network that people own. Businesses, creators, and publishers keep the audiences and communities they build, and no company can take them away or unilaterally shut them down. All users can talk, read, and buy without being watched or tracked from one site to the next. None of this is new. Before the Internet, people's conversations were private, and the groups and audiences they built were their own, with no company in the middle. We lost that when we moved online, and we need it back – the future we set out in our [network philosophy](https://simplex.chat/why.md).
+
+We're building the network to support that future. We invite you to own a part of it: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat).
+
+This Regulation Crowdfunding offering is made available through Wefunder Portal LLC. This investment involves a high degree of risk, including the possible loss of your investment.
+
+---
+
+Source: https://simplex.chat/llms/timeline.md
+
+# SimpleX: timeline
+
+Key milestones, with links to the announcements. All posts: [SimpleX blog](https://simplex.chat/blog.md).
+
+| Date | Milestone |
+|---|---|
+| May 2021 | [SimpleX Chat prototype announced](https://simplex.chat/blog/20210512-simplex-chat-terminal-ui.md) |
+| January 2022 | [SimpleX Chat v1](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md) |
+| March 2022 | [Mobile apps for iOS and Android](https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.md) |
+| November 2022 | [Implementation security assessment by Trail of Bits](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md) |
+| March 2023 | [XFTP – SimpleX File Transfer Protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md) |
+| April 2023 | [Pre-seed funding from Village Global and angel investors](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md) announced (closed in July 2022) |
+| September 2023 | [Desktop app and group directory service](https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md) |
+| March 2024 | [Post-quantum end-to-end encryption](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.md) |
+| April 2024 | [Post-quantum encryption on by default in direct conversations](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md) |
+| June 2024 | [Private message routing protects IP addresses](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) |
+| August 2024 | [Investment from Jack Dorsey and Asymmetric Capital Partners](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) announced (closed in July 2023) |
+| October 2024 | [Cryptographic design review by Trail of Bits](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md) |
+| December 2024 | [Preset servers operated by Flux; business chats](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md) |
+| January 2025 | [Large groups and privacy-preserving content moderation](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md) |
+| April 2026 | [SimpleX Channels and SimpleX Network Consortium](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md) |
+| July 2026 | [SimpleX public names in test](https://simplex.chat/blog/20260722-simplex-public-names.md) |
+| August 2026 | [Equity crowdfunding launched on Wefunder](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md) |
+| September 2026 | [Supporter badges](https://simplex.chat/blog/20260919-simplex-supporter-badges.md) |
+| 12 December 2026 | `.simplex` names sale starts ([simplex.domains](https://simplex.domains/)) |
+| June 2027 | Planned: Community Credits for sustainable communities and servers ([roadmap](https://simplex.chat/index.md)) |
+| December 2027 | Planned: tools to promote communities ([roadmap](https://simplex.chat/index.md)) |
+
diff --git a/llms.txt b/llms.txt
new file mode 100644
index 0000000000..0dd713d071
--- /dev/null
+++ b/llms.txt
@@ -0,0 +1,92 @@
+# SimpleX
+
+> SimpleX is the first messaging network without user identifiers of any kind – no phone numbers, usernames or random IDs – so nobody, including its servers, can see who talks to whom. SimpleX Chat is the free, open-source app for iOS, Android, Linux, macOS and Windows that uses this network, and the company that builds both.
+
+Each conversation uses its own one-way message queues with random addresses, and contacts are stored only on users' devices. Messages are end-to-end encrypted with a double ratchet that adds a post-quantum key exchange on every step. Anyone can run servers; SimpleX Chat and Flux operate the servers preset in the app. Trail of Bits assessed the implementation in 2022 and reviewed the cryptographic design in 2024.
+
+Every page of simplex.chat is also available as Markdown: replace `.html` with `.md` (simplex.chat/docs/simplex.md), or add `.md` to the path (simplex.chat/why.md).
+
+## Start here
+
+- [Key facts](https://simplex.chat/llms/facts.md): numbers with dates and sources; also as [JSON](https://simplex.chat/llms/facts.json)
+- [Answers to common questions](https://simplex.chat/llms/answers.md): how SimpleX works, security, limitations, comparisons, governance, business model
+- [Why we are building SimpleX Network](https://simplex.chat/why.md), and [the film on YouTube](https://www.youtube.com/watch?v=k-GhLNZm8G0)
+- [SimpleX Chat home page](https://simplex.chat/index.md)
+- [The world's most secure messaging](https://simplex.chat/messaging.md): features and comparisons with other messengers
+- [Timeline](https://simplex.chat/llms/timeline.md): milestones from 2021 to the roadmap
+
+## How SimpleX works
+
+- [How SimpleX works](https://simplex.chat/docs/simplex.md): platform overview and comparison with peer-to-peer and federated networks
+- [Glossary](https://simplex.chat/docs/glossary.md)
+- [FAQ](https://simplex.chat/faq.md)
+- [Public names whitepaper](https://simplex.chat/docs/protocol/names-overview.md): names for channels and businesses, without user identifiers
+- [Channels whitepaper](https://simplex.chat/docs/protocol/channels-overview.md): scalable public channels
+- [Chat protocol](https://simplex.chat/docs/protocol/simplex-chat.md)
+- [All documentation](https://simplex.chat/docs.md)
+
+## Protocol specifications
+
+- [SimpleX network overview](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/overview-tjr.md)
+- [SimpleX Messaging Protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/simplex-messaging.md)
+- [Agent protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/agent-protocol.md)
+- [Post-quantum double ratchet](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/pqdr.md)
+- [Security model](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/security.md)
+- [XFTP file transfer protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/xftp.md)
+- [XRCP remote control protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/xrcp.md)
+- [Push notifications](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/push-notifications.md)
+
+## Security
+
+- [Security policy and audits](https://simplex.chat/security.md)
+- [Trail of Bits implementation assessment, 2022](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf)
+- [Trail of Bits cryptographic design review, 2024](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf)
+- [Transparency reports](https://simplex.chat/transparency.md)
+- [Reproducible builds](https://simplex.chat/reproduce.md)
+- [Privacy policy](https://simplex.chat/privacy.md)
+
+## Use SimpleX
+
+- [Download the apps](https://simplex.chat/downloads.md)
+- [App guide](https://simplex.chat/docs/guide/readme.md)
+- [Directory of public groups and channels](https://simplex.chat/directory.md), with live data in [listing.json](https://directory.simplex.chat/data/listing.json)
+- [SimpleX for business](https://simplex.chat/docs/business.md)
+- [Host your own messaging server](https://simplex.chat/docs/server.md) and [file server](https://simplex.chat/docs/xftp-server.md)
+
+## For AI agents and developers
+
+- [SimpleX for AI agents and developers](https://simplex.chat/llms/agents.md): a bot in five minutes, the API, building from source, OpenClaw, asking the team
+- [Bot API guide](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/README.md)
+- [Terminal client](https://simplex.chat/docs/cli.md)
+- [Source code](https://github.com/simplex-chat)
+
+## Company, crowdfunding and investment
+
+- [Crowdfunding page](https://simplex.chat/crowdfunding.md)
+- [Wefunder memo](https://simplex.chat/wefunder.md): the full memo from the Wefunder page
+- [Wefunder page](https://wefunder.com/simplex.chat) and [Wefunder AI profile](https://wefunder.com/simplex.chat.ai.txt)
+- [SimpleX Crowdfunding News](https://simplex.chat/crowdfunding-news.md): the crowdfunding news channel, with links to its recent posts in JSON
+- [Livestream: Foundation for the Future](https://simplex.chat/livestream.md)
+- [About SimpleX Chat](https://simplex.chat/about.md)
+- [Donate](https://simplex.chat/donate.md)
+
+## Blog
+
+- [All posts](https://simplex.chat/blog.md)
+- [SimpleX Network News](https://simplex.chat/news.md): the news channel, with links to its recent posts in JSON
+- [SimpleX Supporter Badges — Send Larger Files That Stay Available Longer, Without Being Identified](https://simplex.chat/blog/20260919-simplex-supporter-badges.md) (2026-09-19)
+- [Nick Rogers: Why I Backed SimpleX Chat in 2022, and Why I Doubled Down](https://simplex.chat/blog/20260908-nick-rogers-why-i-backed-simplex-chat.md) (2026-09-08)
+- [Equity Crowdfunding Launched — You Can Get a Stake in SimpleX Chat](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md) (2026-08-20)
+- [SimpleX Public Names — a Name Nobody Can Take From You](https://simplex.chat/blog/20260722-simplex-public-names.md) (2026-07-22)
+- [SimpleX Channels, SimpleX Network Consortium and Community Crowdfunding — to Preserve Freedom of Speech](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md) (2026-04-30)
+- [SimpleX Chat v6.4.1: welcome your contacts, review members to protect groups, and more.](https://simplex.chat/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.md) (2025-07-29)
+- [SimpleX network: new experience of connecting with people — available in SimpleX Chat v6.4-beta.4](https://simplex.chat/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.md) (2025-07-03)
+- [SimpleX Chat v6.3: new user experience and safety in public groups](https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.md) (2025-03-08)
+- [SimpleX network: large groups and privacy-preserving content moderation](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md) (2025-01-14)
+- [Oppose digital IDs – they break the law and lead to mass scale surveillance](https://simplex.chat/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.md) (2024-12-18)
+
+## Optional
+
+- [Full text of the core pages in one file](https://simplex.chat/llms-full.txt)
+- [Publications about SimpleX](https://simplex.chat/links.md): reviews, articles, videos, podcasts and community projects
+- [Translations](https://simplex.chat/docs/translations.md)
diff --git a/llms/agents.md b/llms/agents.md
new file mode 100644
index 0000000000..8517e953e4
--- /dev/null
+++ b/llms/agents.md
@@ -0,0 +1,158 @@
+# SimpleX for AI agents and developers
+
+SimpleX is a messaging network without user identifiers. A program connects to it the same way a person does: it holds its own keys, creates addresses it can share and delete, and needs no phone number, platform account or API key. The network does not distinguish a person from an agent, and no platform can suspend an agent's identity or see who it talks to.
+
+What you can build:
+
+- an assistant that its owner reaches privately from the SimpleX Chat app, on any device;
+- a support or search bot for many users, with an LLM or without one;
+- communication between agents with no platform in the middle;
+- moderation, broadcast and bridge bots for groups and channels.
+
+## Make a bot in five minutes
+
+### Node.js
+
+```sh
+npm i simplex-chat
+```
+
+```javascript
+(async () => {
+  const {bot} = await import("simplex-chat")
+  await bot.run({
+    profile: {displayName: "Squaring bot example", fullName: ""},
+    dbOpts: {type: "sqlite", filePrefix: "./squaring_bot"},
+    options: {
+      addressSettings: {welcomeMessage: "Send a number, I will square it."},
+    },
+    onMessage: async (ci, content, chat) => {
+      const n = +content.text
+      const reply = typeof n === "number" && !isNaN(n)
+                    ? `${n} * ${n} = ${n * n}`
+                    : `this is not a number`
+      await chat.apiSendTextReply(ci, reply)
+    }
+  })
+})()
+```
+
+On start, the bot creates its SimpleX address and prints it (`Bot address: ...`). Open this address in the SimpleX Chat app to talk to the bot. Library: [simplex-chat on npm](https://www.npmjs.com/package/simplex-chat), [source and examples](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-nodejs).
+
+### Python (3.11+)
+
+```sh
+pip install simplex-chat
+```
+
+```python
+import re
+from simplex_chat import Bot, BotProfile, Message, SqliteDb, TextMessage
+
+bot = Bot(
+    profile=BotProfile(display_name="Squaring bot"),
+    db=SqliteDb(file_prefix="./squaring_bot"),
+    welcome="Send me a number, I'll square it.",
+)
+
+@bot.on_message(content_type="text", text=re.compile(r"^-?\d+(\.\d+)?$"))
+async def square(msg: TextMessage) -> None:
+    n = float(msg.text or "0")
+    await msg.reply(f"{n} * {n} = {n * n}")
+
+@bot.on_message(content_type="text")
+async def fallback(msg: Message) -> None:
+    await msg.reply("Send me a number, like 7 or 3.14.")
+
+if __name__ == "__main__":
+    bot.run()
+```
+
+The bot logs its address on start. Library: [simplex-chat on PyPI](https://pypi.org/project/simplex-chat/), [source and examples](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-python).
+
+## Use the terminal client as an API server, from any language
+
+Install the terminal client on Linux or macOS:
+
+```sh
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/install.sh | bash
+```
+
+Run it as a local WebSocket server:
+
+```sh
+simplex-chat -p 5225
+```
+
+Your program connects to `ws://localhost:5225` and sends JSON commands, for example to create a long-term address:
+
+```json
+{"corrId": "1", "cmd": "/address"}
+```
+
+Responses carry the same `corrId`; chat events, such as received messages, arrive as separate messages. The command strings are the same as in the app's chat console. The WebSocket API has no authentication and binds to localhost: run your program on the same machine, or put a TLS proxy with authentication in front of it.
+
+- [Bot API guide](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/README.md)
+- [Commands](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/COMMANDS.md)
+- [Events](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/EVENTS.md)
+- [Types](https://raw.githubusercontent.com/simplex-chat/simplex-chat/stable/bots/api/TYPES.md)
+- [Terminal client guide](https://simplex.chat/docs/cli.md)
+
+## Build the terminal client from source
+
+With Docker, on Linux:
+
+```sh
+git clone https://github.com/simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+DOCKER_BUILDKIT=1 docker build --output ~/.local/bin .
+```
+
+With GHC 9.6.3 and cabal 3.10.1.0 installed via [GHCup](https://www.haskell.org/ghcup/), on Linux:
+
+```sh
+git clone https://github.com/simplex-chat/simplex-chat.git
+cd simplex-chat
+git checkout stable
+apt-get update && apt-get install -y build-essential libgmp3-dev zlib1g-dev
+cp scripts/cabal.project.local.linux cabal.project.local
+cabal update
+cabal install simplex-chat
+```
+
+On macOS, install OpenSSL with `brew install openssl@3.0` and use `scripts/cabal.project.local.mac` instead. Full instructions: [terminal client guide](https://simplex.chat/docs/cli.md).
+
+## OpenClaw
+
+A community plugin connects [OpenClaw](https://github.com/openclaw/openclaw) to SimpleX through a locally running terminal client, so you can talk to your OpenClaw assistant from the SimpleX Chat app:
+
+```sh
+openclaw plugins install @dangoldbj/openclaw-simplex
+openclaw plugins enable openclaw-simplex
+```
+
+Source: [github.com/dangoldbj/openclaw-simplex](https://github.com/dangoldbj/openclaw-simplex).
+
+## Run your own servers
+
+- [SMP messaging server](https://simplex.chat/docs/server.md)
+- [XFTP file server](https://simplex.chat/docs/xftp-server.md)
+
+## Protocol specifications
+
+- [SimpleX network overview](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/overview-tjr.md)
+- [SimpleX Messaging Protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/simplex-messaging.md)
+- [Agent protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/agent-protocol.md)
+- [Post-quantum double ratchet](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/pqdr.md)
+- [Security model](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/security.md)
+- [XFTP file transfer protocol](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/xftp.md)
+- [Chat protocol](https://simplex.chat/docs/protocol/simplex-chat.md)
+
+## Ask the SimpleX team
+
+In the SimpleX Chat app, open the "Ask SimpleX Team" chat, or connect via [simplex.chat/contact](https://simplex.chat/contact#/?v=2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion). A support bot answers first:
+
+- send `/team` to reach the team – not a bot; the team replies within 24 hours, or 48 hours at weekends;
+- send `/grok` for an instant answer from an AI assistant.
+
diff --git a/llms/answers.md b/llms/answers.md
new file mode 100644
index 0000000000..7d6afcf983
--- /dev/null
+++ b/llms/answers.md
@@ -0,0 +1,74 @@
+# SimpleX: answers to common questions
+
+Short answers with links to the full documentation. Numbers are in [key facts](https://simplex.chat/llms/facts.md).
+
+## What is SimpleX, in one sentence?
+
+SimpleX is the first messaging network without user identifiers of any kind – no phone numbers, usernames or random IDs – so nobody, including its servers, can see who talks to whom.
+
+## What is the difference between SimpleX network and SimpleX Chat?
+
+SimpleX network is the open protocol and the servers that relay messages. SimpleX Chat is the free, open-source app (iOS, Android, Linux, macOS, Windows and a terminal client) that uses the network, and also the company that builds both.
+
+## How does SimpleX deliver messages without user identifiers?
+
+Each conversation uses its own pair of one-way message queues, one for each direction, usually on different servers. A queue has a random address that is used only for that conversation. Contacts and groups are stored only on users' devices. To connect, people share a one-time link or a QR code, which also carries the keys for end-to-end encryption, so servers cannot substitute them. Details: [How SimpleX works](https://simplex.chat/docs/simplex.md), [protocol overview](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/overview-tjr.md).
+
+## What can servers and network observers see?
+
+Servers relay end-to-end encrypted messages and delete them once they are delivered. A server sees the random addresses of the queues it hosts and the times when messages arrive and are received. All messages are padded to the same size. With private message routing, the sender chooses the forwarding server and the recipient chooses the destination server, so neither side can observe the other's IP address. A server cannot see who talks to whom, cannot read messages, and cannot add or change them undetectably. Details: [security model](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/security.md).
+
+## How strong is the encryption?
+
+Messages are end-to-end encrypted with a double ratchet that gives forward secrecy and recovery after a key compromise. A post-quantum key exchange (sntrup761) is added on every ratchet step and is on by default in direct conversations. An additional encryption layer between servers and devices prevents correlating sent and received traffic. Details: [post-quantum double ratchet](https://raw.githubusercontent.com/simplex-chat/simplexmq/stable/protocol/pqdr.md).
+
+## Why are public channels not end-to-end encrypted?
+
+By design. No system can provide encrypted messages, scalable broadcast and private participation at the same time. Anyone can join a channel through its public link, so encrypting its content would protect nothing; protecting who participates does. SimpleX channels make participation private: relays see the content, but not subscribers' identities or network addresses, and participation in different channels cannot be linked. Details: [SimpleX Channels](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md), [channels whitepaper](https://simplex.chat/docs/protocol/channels-overview.md).
+
+## Is SimpleX audited?
+
+Yes. Trail of Bits assessed the implementation in October 2022 and reviewed the cryptographic design in July 2024. A third audit was completed in 2026 and will be published. Reports: [2022](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf), [2024](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf).
+
+## What are SimpleX's limitations?
+
+- Post-quantum key exchange is used in direct conversations, not yet in groups.
+- An observer who can watch the traffic of both users can confirm that they communicate.
+- Resolving a public name reveals interest in that name to one resolver server, but not who asked.
+
+## How does SimpleX compare with Signal, Session, Matrix, Briar and others?
+
+Every other messaging network assigns users an identifier: Signal and WhatsApp use phone numbers, Matrix uses `@user:server` IDs, and Session, Briar, Cwtch and Nostr identify users by long-term public keys or onion addresses. These identifiers let the network, or anyone observing it, link a user's conversations. SimpleX has none. A side-by-side comparison of encryption properties is on the [messaging page](https://simplex.chat/messaging/#messengers-comparison), and a technical comparison with peer-to-peer protocols is in [How SimpleX works](https://simplex.chat/docs/simplex.md).
+
+## Can people find or contact me without my consent?
+
+No. Nobody can contact you unless you share a one-time link or your address. An address is optional and can be changed or deleted without losing contacts.
+
+## Who controls the network?
+
+Nobody alone. Anyone can run servers. SimpleX Chat and Flux are preset in the app, and when both are enabled the app uses servers of both operators in each conversation. The SimpleX Network Consortium, an agreement between the non-profit SimpleX Network Foundation and SimpleX Chat, licenses the protocol to the foundation permanently, so it stays available regardless of who owns the company. Details: [blog](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md).
+
+## Is SimpleX free and open source?
+
+Yes. The apps are free, and the code is open source under AGPL-3.0: [github.com/simplex-chat](https://github.com/simplex-chat).
+
+## How will SimpleX Chat make money?
+
+Private messaging stays free. Channels and businesses will pay for public names, business messaging and servers for big channels. Users have already donated over $650,000. Details: [Wefunder memo](https://simplex.chat/wefunder.md).
+
+## What are SimpleX public names?
+
+Optional, human-readable names for channels and businesses, such as `#example` or `@example.simplex`, registered on a public blockchain and controlled only by their owner's key. Names do not identify users and are not needed to use the network. Sale starts on 12 December 2026. Details: [public names whitepaper](https://simplex.chat/docs/protocol/names-overview.md).
+
+## How can AI agents and developers use SimpleX?
+
+An agent connects to the network like a person: it holds its own keys and addresses, and no platform account is needed. See [SimpleX for AI agents and developers](https://simplex.chat/llms/agents.md).
+
+## How can I invest in SimpleX Chat?
+
+SimpleX Chat runs an equity crowdfunding offering on Wefunder: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat). The memo is reproduced at [simplex.chat/wefunder.md](https://simplex.chat/wefunder.md). Investing involves a high degree of risk, including the possible loss of your investment.
+
+## How do I contact the SimpleX team?
+
+In the SimpleX Chat app, open the "Ask SimpleX Team" chat, or connect via [simplex.chat/contact](https://simplex.chat/contact#/?v=2&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23%2F%3Fv%3D1%26dh%3DMCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%253D%26srv%3Dbylepyau3ty4czmn77q4fglvperknl4bi2eb2fdy2bh4jxtf32kf73yd.onion). A support bot answers first; send `/team` to reach the team.
+
diff --git a/llms/facts.json b/llms/facts.json
new file mode 100644
index 0000000000..75ccaa2dbf
--- /dev/null
+++ b/llms/facts.json
@@ -0,0 +1,369 @@
+{
+  "updated": "2026-10-08",
+  "groups": [
+    {
+      "title": "Network and users",
+      "facts": [
+        {
+          "fact": "User identifiers on the network",
+          "value": "None – no phone numbers, usernames, account IDs or random user IDs",
+          "asOf": "2026",
+          "sources": [
+            {
+              "title": "How SimpleX works",
+              "url": "https://simplex.chat/docs/simplex.md"
+            }
+          ]
+        },
+        {
+          "fact": "Monthly active users",
+          "value": "600,000+",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "User growth",
+          "value": "about 70% in the last six months",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "App downloads",
+          "value": "3 million+",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Messages per day via preset servers",
+          "value": "20 million+",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Paid marketing",
+          "value": "none before the equity crowdfunding campaign",
+          "asOf": "until August 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Independent publications about SimpleX",
+          "value": "200+ reviews, posts and videos in 20+ languages",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Links",
+              "url": "https://simplex.chat/links.md"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "title": "Network participants",
+      "facts": [
+        {
+          "fact": "Servers run by volunteers",
+          "value": "about 1,000",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Preset server operators",
+          "value": "SimpleX Chat and Flux",
+          "asOf": "since December 2024",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md"
+            }
+          ]
+        },
+        {
+          "fact": "Public channels created",
+          "value": "12,500+ in the five months since scalable channels shipped",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Curated directory",
+          "value": "500+ public groups and channels, 30% active daily",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            },
+            {
+              "title": "Directory",
+              "url": "https://simplex.chat/directory.md"
+            }
+          ]
+        },
+        {
+          "fact": "Businesses supporting customers over SimpleX",
+          "value": "50+",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "GitHub",
+          "value": "19,000+ stars, 1,400+ forks",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            },
+            {
+              "title": "GitHub",
+              "url": "https://github.com/simplex-chat/simplex-chat"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "title": "Security",
+      "facts": [
+        {
+          "fact": "End-to-end encryption",
+          "value": "double ratchet with post-quantum key exchange (sntrup761) on every ratchet step, on by default in direct conversations",
+          "asOf": "since v5.7, April 2024",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md"
+            }
+          ]
+        },
+        {
+          "fact": "IP address protection",
+          "value": "private message routing: 2-hop routing where the sender chooses the forwarding relay and the recipient chooses the destination relay, so neither side observes the other's IP address",
+          "asOf": "since v5.8, June 2024",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md"
+            }
+          ]
+        },
+        {
+          "fact": "Implementation security assessment",
+          "value": "Trail of Bits",
+          "asOf": "October 2022",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md"
+            },
+            {
+              "title": "Report",
+              "url": "https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf"
+            }
+          ]
+        },
+        {
+          "fact": "Cryptographic design review",
+          "value": "Trail of Bits",
+          "asOf": "July 2024",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md"
+            },
+            {
+              "title": "Report",
+              "url": "https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf"
+            }
+          ]
+        },
+        {
+          "fact": "Third Trail of Bits audit",
+          "value": "completed, to be published",
+          "asOf": "2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Licence",
+          "value": "AGPL-3.0",
+          "asOf": "2026",
+          "sources": [
+            {
+              "title": "LICENSE",
+              "url": "https://github.com/simplex-chat/simplex-chat/blob/stable/LICENSE"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "title": "Company and funding",
+      "facts": [
+        {
+          "fact": "Founder",
+          "value": "Evgeny Poberezkin, creator of the Ajv JSON Schema validator",
+          "asOf": "2026",
+          "sources": [
+            {
+              "title": "Ajv",
+              "url": "https://github.com/ajv-validator/ajv"
+            }
+          ]
+        },
+        {
+          "fact": "Total investment to date",
+          "value": "$1.7M",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "User donations",
+          "value": "$650,000+, including from Vitalik Buterin",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        },
+        {
+          "fact": "Prior investors",
+          "value": "Village Global and angel investors (pre-seed, closed in July 2022); Jack Dorsey and Asymmetric Capital Partners (closed in July 2023)",
+          "asOf": "announced April 2023 and August 2024",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md"
+            }
+          ]
+        },
+        {
+          "fact": "Equity crowdfunding",
+          "value": "on Wefunder, launched 20 August 2026",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md"
+            },
+            {
+              "title": "Crowdfunding",
+              "url": "https://simplex.chat/crowdfunding.md"
+            }
+          ]
+        },
+        {
+          "fact": "Governance",
+          "value": "SimpleX Network Consortium: an agreement between the non-profit SimpleX Network Foundation and SimpleX Chat",
+          "asOf": "2026",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md"
+            }
+          ]
+        },
+        {
+          "fact": "Business model",
+          "value": "free private messaging; channels and businesses pay for public names, business messaging and servers for big channels",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "Wefunder memo",
+              "url": "https://simplex.chat/wefunder.md"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "title": "Public names",
+      "facts": [
+        {
+          "fact": "Test names (.testing)",
+          "value": "available since v7-beta",
+          "asOf": "July 2026",
+          "sources": [
+            {
+              "title": "Blog",
+              "url": "https://simplex.chat/blog/20260722-simplex-public-names.md"
+            }
+          ]
+        },
+        {
+          "fact": ".simplex names sale",
+          "value": "starts 12 December 2026, 18:00 UTC",
+          "asOf": "October 2026",
+          "sources": [
+            {
+              "title": "simplex.domains",
+              "url": "https://simplex.domains/"
+            }
+          ]
+        },
+        {
+          "fact": "Registry",
+          "value": "SimpleX Name Service, a fork of ENS on Ethereum, without off-chain indexer or metadata services",
+          "asOf": "July 2026",
+          "sources": [
+            {
+              "title": "Whitepaper",
+              "url": "https://simplex.chat/docs/protocol/names-overview.md"
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}
diff --git a/llms/facts.md b/llms/facts.md
new file mode 100644
index 0000000000..a834ce842c
--- /dev/null
+++ b/llms/facts.md
@@ -0,0 +1,59 @@
+# SimpleX: key facts
+
+Facts about SimpleX network and SimpleX Chat, each with the date it was stated and its source. Updated 2026-10-08. Machine-readable version: [simplex.chat/llms/facts.json](https://simplex.chat/llms/facts.json).
+
+## Network and users
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| User identifiers on the network | None – no phone numbers, usernames, account IDs or random user IDs | 2026 | [How SimpleX works](https://simplex.chat/docs/simplex.md) |
+| Monthly active users | 600,000+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| User growth | about 70% in the last six months | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| App downloads | 3 million+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Messages per day via preset servers | 20 million+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Paid marketing | none before the equity crowdfunding campaign | until August 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Independent publications about SimpleX | 200+ reviews, posts and videos in 20+ languages | October 2026 | [Links](https://simplex.chat/links.md) |
+
+## Network participants
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Servers run by volunteers | about 1,000 | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Preset server operators | SimpleX Chat and Flux | since December 2024 | [Blog](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md) |
+| Public channels created | 12,500+ in the five months since scalable channels shipped | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Curated directory | 500+ public groups and channels, 30% active daily | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md), [Directory](https://simplex.chat/directory.md) |
+| Businesses supporting customers over SimpleX | 50+ | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| GitHub | 19,000+ stars, 1,400+ forks | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md), [GitHub](https://github.com/simplex-chat/simplex-chat) |
+
+## Security
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| End-to-end encryption | double ratchet with post-quantum key exchange (sntrup761) on every ratchet step, on by default in direct conversations | since v5.7, April 2024 | [Blog](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md) |
+| IP address protection | private message routing: 2-hop routing where the sender chooses the forwarding relay and the recipient chooses the destination relay, so neither side observes the other's IP address | since v5.8, June 2024 | [Blog](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) |
+| Implementation security assessment | Trail of Bits | October 2022 | [Blog](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md), [Report](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Chat_Final_Report_11_03_2022.pdf) |
+| Cryptographic design review | Trail of Bits | July 2024 | [Blog](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md), [Report](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SimpleX_Design_Review_2024_Summary_Report_12_08_2024.pdf) |
+| Third Trail of Bits audit | completed, to be published | 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Licence | AGPL-3.0 | 2026 | [LICENSE](https://github.com/simplex-chat/simplex-chat/blob/stable/LICENSE) |
+
+## Company and funding
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Founder | Evgeny Poberezkin, creator of the Ajv JSON Schema validator | 2026 | [Ajv](https://github.com/ajv-validator/ajv) |
+| Total investment to date | $1.7M | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| User donations | $650,000+, including from Vitalik Buterin | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+| Prior investors | Village Global and angel investors (pre-seed, closed in July 2022); Jack Dorsey and Asymmetric Capital Partners (closed in July 2023) | announced April 2023 and August 2024 | [Blog](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) |
+| Equity crowdfunding | on Wefunder, launched 20 August 2026 | October 2026 | [Blog](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md), [Crowdfunding](https://simplex.chat/crowdfunding.md) |
+| Governance | SimpleX Network Consortium: an agreement between the non-profit SimpleX Network Foundation and SimpleX Chat | 2026 | [Blog](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md) |
+| Business model | free private messaging; channels and businesses pay for public names, business messaging and servers for big channels | October 2026 | [Wefunder memo](https://simplex.chat/wefunder.md) |
+
+## Public names
+
+| Fact | Value | As of | Source |
+|---|---|---|---|
+| Test names (.testing) | available since v7-beta | July 2026 | [Blog](https://simplex.chat/blog/20260722-simplex-public-names.md) |
+| .simplex names sale | starts 12 December 2026, 18:00 UTC | October 2026 | [simplex.domains](https://simplex.domains/) |
+| Registry | SimpleX Name Service, a fork of ENS on Ethereum, without off-chain indexer or metadata services | July 2026 | [Whitepaper](https://simplex.chat/docs/protocol/names-overview.md) |
+
+
diff --git a/llms/timeline.md b/llms/timeline.md
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--- /dev/null
+++ b/llms/timeline.md
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+# SimpleX: timeline
+
+Key milestones, with links to the announcements. All posts: [SimpleX blog](https://simplex.chat/blog.md).
+
+| Date | Milestone |
+|---|---|
+| May 2021 | [SimpleX Chat prototype announced](https://simplex.chat/blog/20210512-simplex-chat-terminal-ui.md) |
+| January 2022 | [SimpleX Chat v1](https://simplex.chat/blog/20220112-simplex-chat-v1-released.md) |
+| March 2022 | [Mobile apps for iOS and Android](https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.md) |
+| November 2022 | [Implementation security assessment by Trail of Bits](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md) |
+| March 2023 | [XFTP – SimpleX File Transfer Protocol](https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.md) |
+| April 2023 | [Pre-seed funding from Village Global and angel investors](https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.md) announced (closed in July 2022) |
+| September 2023 | [Desktop app and group directory service](https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md) |
+| March 2024 | [Post-quantum end-to-end encryption](https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.md) |
+| April 2024 | [Post-quantum encryption on by default in direct conversations](https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.md) |
+| June 2024 | [Private message routing protects IP addresses](https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.md) |
+| August 2024 | [Investment from Jack Dorsey and Asymmetric Capital Partners](https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.md) announced (closed in July 2023) |
+| October 2024 | [Cryptographic design review by Trail of Bits](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md) |
+| December 2024 | [Preset servers operated by Flux; business chats](https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.md) |
+| January 2025 | [Large groups and privacy-preserving content moderation](https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.md) |
+| April 2026 | [SimpleX Channels and SimpleX Network Consortium](https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.md) |
+| July 2026 | [SimpleX public names in test](https://simplex.chat/blog/20260722-simplex-public-names.md) |
+| August 2026 | [Equity crowdfunding launched on Wefunder](https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.md) |
+| September 2026 | [Supporter badges](https://simplex.chat/blog/20260919-simplex-supporter-badges.md) |
+| 12 December 2026 | `.simplex` names sale starts ([simplex.domains](https://simplex.domains/)) |
+| June 2027 | Planned: Community Credits for sustainable communities and servers ([roadmap](https://simplex.chat/index.md)) |
+| December 2027 | Planned: tools to promote communities ([roadmap](https://simplex.chat/index.md)) |
+
diff --git a/messaging.md b/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Why SimpleX is unique
+
+### You have complete privacy
+
+SimpleX protects the privacy of your profile, contacts and metadata, hiding it from SimpleX network servers and any observers.
+
+Unlike any other existing messaging network, SimpleX has no identifiers assigned to the users — **not even random numbers**.
+
+### You are protected from spam and abuse
+
+Because you have no identifier or fixed address on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+### You control your data
+
+SimpleX stores all user data on client devices in a **portable encrypted database format** — it can be transferred to another device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+### You own SimpleX network
+
+The SimpleX network is fully decentralised and independent of any crypto-currency or any other network, other than the Internet.
+
+You can **use SimpleX with your own servers** or with the servers provided by us — and still connect to any user.
+
+# Full privacy of your identity, profile, contacts and metadata
+
+Unlike other messaging networks, SimpleX has **no identifiers assigned to the users**. It does not rely on phone numbers, domain-based addresses (like email or XMPP), usernames, public keys or even random numbers to identify its users — SimpleX server operators don't know how many people use their servers.
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# The best protection from spam and abuse
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# Ownership, control and security of your data
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+There are no identifiers or ciphertext in common between sent and received server traffic — if anybody is observing it, they cannot easily determine who communicates with whom, even if TLS is compromised.
+
+# Fully decentralised — users own the SimpleX network
+
+You can **use SimpleX with your own servers** and still communicate with people who use the servers preconfigured in the apps.
+
+SimpleX network uses an [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) and provides [SDK to create chat bots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), allowing implementation of services that users can interact with via SimpleX Chat apps — we're really looking forward to seeing what SimpleX services you will build.
+
+If you are considering developing for the SimpleX network, for example, the chat bot for SimpleX app users, or the integration of the SimpleX Chat library into your mobile apps, please [get in touch](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) for any advice and support.
+
+## Features
+
+E2E-encrypted messages with markdown and editing
+
+E2E-encrypted
+images, videos and files
+
+E2E-encrypted decentralized groups — only users know they exist
+
+E2E-encrypted voice messages
+
+Disappearing messages
+
+E2E-encrypted
+audio and video calls
+
+Portable encrypted app storage — move profile to another device
+
+Incognito mode —
+unique to SimpleX Chat
+
+## What makes SimpleX private
+
+### Temporary anonymous pairwise identifiers
+
+SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member.
+
+It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.
+
+### Out-of-band key exchange
+
+Many communication networks are vulnerable to MITM attacks by servers or network providers.
+
+To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.
+
+### 2-layers of end-to-end encryption
+
+Double-ratchet protocol —
+OTR messaging with perfect forward secrecy and break-in recovery.
+
+NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.
+
+### Message integrity verification
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### Additional layer of server encryption
+
+Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.
+
+### Message mixing to reduce correlation
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### Secure authenticated TLS transport
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+Connection resumption is disabled to prevent session attacks.
+
+### Optional access via Tor
+
+To protect your IP address you can access the servers via Tor or some other transport overlay network.
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Unidirectional message queues
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+It reduces the attack vectors, compared with traditional message brokers, and available meta-data.
+
+### Multiple layers of content padding
+
+SimpleX uses content padding for each encryption layer to frustrate message size attacks.
+
+It makes messages of different sizes look the same to the servers and network observers.
+
+## SimpleX Network
+
+SimpleX Chat provides the best privacy by combining the advantages of P2P and federated networks.
+
+### Unlike P2P networks
+
+All messages are sent via the servers, both providing better metadata privacy and reliable asynchronous message delivery, while avoiding many .
+
+# Comparison with P2P messaging protocols
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messaging protocols and apps have various problems that make them less reliable than SimpleX, more complex to analyse, and vulnerable to several types of attack.
+
+1. P2P networks rely on some variant of [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) to route messages. DHT designs have to balance delivery guarantee and latency. SimpleX has both better delivery guarantee and lower latency than P2P, because the message can be redundantly passed via several servers in parallel, using the servers chosen by the recipient. In P2P networks the message is passed through *O(log N)* nodes sequentially, using nodes chosen by the algorithm.
+2. SimpleX design, unlike most P2P networks, has no global user identifiers of any kind, even temporary, and only uses temporary pairwise identifiers, providing better anonymity and metadata protection.
+3. P2P does not solve [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problem, and most existing implementations do not use out-of-band messages for the initial key exchange. SimpleX uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### Unlike federated networks
+
+SimpleX relay servers do NOT store user profiles, contacts and delivered messages, do NOT connect to each other, and there is NO servers directory.
+
+---
+
+### SimpleX network
+
+servers provide unidirectional queues to connect the users, but they have no visibility of the network connection graph — only the users do.
+
+## SimpleX explained
+
+1. What users experience
+
+2. How does it work
+
+3. What servers see
+
+1. What users experience
+
+You can create contacts and groups, and have two-way conversations, as in any other messenger.
+
+How can it work with unidirectional queues and without user profile identifiers?
+
+2. How does it work
+
+For each connection you use two separate messaging queues to send and receive messages via different servers.
+
+Servers only pass messages one way, without having the full picture of user's conversations or connections.
+
+3. What servers see
+
+The servers have separate anonymous credentials for each queue, and do not know which users they belong to.
+
+Users can further improve metadata privacy by using Tor to access servers, preventing correlation by IP address.
+
+## Comparison with other protocols
+
+|  |  | Signal, big platforms | XMPP, Matrix | P2P protocols |
+| --- | --- | --- | --- | --- |
+| Requires global identity | No - private | Yes [1] | Yes [2] | Yes [3] |
+| Possibility of MITM | No - secure [4] | Yes [5] | Yes | Yes |
+| Dependence on DNS | No - resilient | Yes | Yes | No |
+| Single or centralized network | No - decentralized | Yes | No - federated [6] | Yes [7] |
+| Central component or other network-wide attack | No - resilient | Yes | Yes [2] | Yes [8] |
+
+---
+
+1. Usually based on a phone number, in some cases on usernames
+2. DNS-based addresses
+3. Public key or some other globally unique ID
+4. SimpleX relays cannot compromise e2e encryption. Verify security code to mitigate attack on out-of-band channel
+5. If operator's servers are compromised. Verify security code in Signal and some other apps to mitigate it
+6. Does not protect users' metadata privacy
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. P2P networks either have a central authority or the whole network can be compromised — [see here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [see here](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/messaging/index.html b/messaging/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connection resumption is disabled to prevent session attacks.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It reduces the attack vectors, compared with traditional message brokers, and available meta-data.</p>
                             
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                             <p class="text-grey-black dark:text-white text-[14px] text-center">It makes messages of different sizes look the same to the servers and network observers.</p>
                             
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 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/news.md b/news.md
new file mode 100644
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--- /dev/null
+++ b/news.md
@@ -0,0 +1,5 @@
+# SimpleX Network News
+
+The news about SimpleX Network technology, governance and anything related to its development, published as a SimpleX channel. Join it in the SimpleX Chat app: [SimpleX Network News](https://smp18.simplex.im/c#grcfG3ulVI4Sh6ow33qBsmSk7uEy3gRSl2KkJ5ER6tA).
+
+Recent posts in JSON, with the channel profile and subscriber count, from any of the channel relays: [relay1.simplex.chat](https://relay1.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json), [relay2.simplex.chat](https://relay2.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json), [relay3.simplex.chat](https://relay3.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json).
diff --git a/news/index.html b/news/index.html
index 7a96661cb9..f2ff00ad37 100644
--- a/news/index.html
+++ b/news/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/news.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,19 +482,19 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div data-simplex-channel-preview="" data-channel-link="https://smp18.simplex.im/c#grcfG3ulVI4Sh6ow33qBsmSk7uEy3gRSl2KkJ5ER6tA" data-channel-id="8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=" data-relay-domains="relay1.simplex.chat,relay2.simplex.chat,relay3.simplex.chat" data-app-download-buttons="off" data-color-scheme="site" data-top-offset="54"></div>
+        <div data-simplex-channel-preview
+    data-channel-link="https://smp18.simplex.im/c#grcfG3ulVI4Sh6ow33qBsmSk7uEy3gRSl2KkJ5ER6tA"
+    data-channel-id="8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w="
+    data-relay-domains="relay1.simplex.chat,relay2.simplex.chat,relay3.simplex.chat"
+    data-app-download-buttons="off"
+    data-color-scheme="site"
+    data-top-offset="54"
+></div>
+<template data-markdown>
+<p>The news about SimpleX Network technology, governance and anything related to its development, published as a SimpleX channel. Join it in the SimpleX Chat app: <a href="https://smp18.simplex.im/c#grcfG3ulVI4Sh6ow33qBsmSk7uEy3gRSl2KkJ5ER6tA">SimpleX Network News</a>.</p>
+<p>Recent posts in JSON, with the channel profile and subscriber count, from any of the channel relays: <a href="https://relay1.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json">relay1.simplex.chat</a>, <a href="https://relay2.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json">relay2.simplex.chat</a>, <a href="https://relay3.simplex.chat/channel/8Ge2ASVRkbDhdJc05ZgSSnZmSjw3UMUaQW_QttI0j_w=.json">relay3.simplex.chat</a>.</p></template>
 <script src="/js/channel-preview.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/contact.md b/nl/contact.md
new file mode 100644
index 0000000000..e776a51c48
--- /dev/null
+++ b/nl/contact.md
@@ -0,0 +1,66 @@
+# Je hebt een adres ontvangen om verbinding te maken met SimpleX Chat
+
+## Scan de QR-code met de SimpleX Chat app op je telefoon of tablet.
+
+De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina — ze zijn opgenomen in het hash-fragment van de link-URL.
+
+Heb je de SimpleX Chat nog niet gedownload?
+
+Gebruik onderstaande links om de app te downloaden.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan de QR-code van de mobiele app
+
+# Je hebt een adres ontvangen om verbinding te maken met SimpleX Chat
+
+Om een verbinding te maken:
+
+Installeer de SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid)
+
+1
+
+Maak verbinding met de app
+
+Open de Simplex app
+
+2
+
+Tik op de knop 'verbinden' in de app
+
+3
+
+## Scan de QR-code met de SimpleX Chat app
+
+De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina bekijkt -
+ze zijn opgenomen in het hash-fragment van de link-URL.
+
+## SimpleX chat installeren op terminal
+
+Gebruik deze opdracht:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Zie SimpleX chat GitHub repository voor instructies over hoe u deze kunt downloaden of compileren vanuit de broncode.
+
+---
+
+## Als u SimpleX Chat al voor de terminal hebt geïnstalleerd
+
+Als u al hebt geïnstalleerd SimpleX Chat voor de terminal v1.0.0+, kopieer de onderstaande opdracht en gebruik deze in de chat:
+
+## Word lid van SimpleX
+
+Wij nodigen u uit om deel te nemen aan de conversatie
+
+[Bezoek ons op REDDIT](https://www.reddit.com/r/SimpleXChat/) [Volg ons op GitHub](https://github.com/simplex-chat) [Doneer hier om ons te helpen](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Schrijf u in om onze updates te ontvangen
+
+---
+
+Verkrijg SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid)
diff --git a/nl/contact/index.html b/nl/contact/index.html
index 4666f90190..7c8802e6ea 100644
--- a/nl/contact/index.html
+++ b/nl/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Je hebt een adres ontvangen om verbinding te maken met SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan de QR-code met de SimpleX Chat app op je telefoon of tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina — ze zijn opgenomen in het hash-fragment van de link-URL.
+                De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina &mdash; ze zijn opgenomen in het hash-fragment van de link-URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Heb je de SimpleX Chat nog niet gedownload?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Gebruik onderstaande links om de app te downloaden.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installeer de SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Tik op de knop <span class="text-active-blue">'verbinden'</span> in de app</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Tik op de knop <span class='text-active-blue'>'verbinden'</span> in de app</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan de QR-code met de SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX chat installeren op terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Als u SimpleX Chat al voor de terminal hebt geïnstalleerd</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Schrijf u in om onze updates te ontvangen</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Voer uw e-mail adres in">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Verkrijg SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/fdroid.md b/nl/fdroid.md
new file mode 100644
index 0000000000..1aba37ab55
--- /dev/null
+++ b/nl/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stabiele en bètaversies gebouwd door de ontwikkelaars
+
+Om het toe te voegen aan uw F-Droid-client scan de QR-code of gebruik deze URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stabiele versies gebouwd door F-Droid.org
+
+De releases voor deze repository vinden enkele dagen later plaats.
+
+SimpleX Chat- en F-Droid.org-repository's ondertekenen builds met de verschillende sleutels. Om over te stappen, alstublieft [exporteer](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) de chatdatabase en installeer de app opnieuw.
diff --git a/nl/fdroid/index.html b/nl/fdroid/index.html
index d41accebd1..4780d74f5b 100644
--- a/nl/fdroid/index.html
+++ b/nl/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stabiele en bètaversies gebouwd door de ontwikkelaars</p>
-                        <p>Om het toe te voegen aan uw F-Droid-client <span class="hide-on-mobile">scan de QR-code of</span> gebruik deze URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Om het toe te voegen aan uw F-Droid-client <span class='hide-on-mobile'>scan de QR-code of</span> gebruik deze URL:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stabiele versies gebouwd door F-Droid.org</p>
                 <p class="mb-2">De releases voor deze repository vinden enkele dagen later plaats.</p>
-                <p class="mb-2">SimpleX Chat- en F-Droid.org-repository's ondertekenen builds met de verschillende sleutels. Om over te stappen, alstublieft <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exporteer</a> de chatdatabase en installeer de app opnieuw.</p>
+                <p class="mb-2">SimpleX Chat- en F-Droid.org-repository's ondertekenen builds met de verschillende sleutels. Om over te stappen, alstublieft <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>exporteer</a> de chatdatabase en installeer de app opnieuw.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/file.md b/nl/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/nl/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/nl/file/index.html b/nl/file/index.html
index f8c09d15a1..4cd0efc47b 100644
--- a/nl/file/index.html
+++ b/nl/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/index.html b/nl/index.html
index d07d087c4f..8e18caf3bf 100644
--- a/nl/index.html
+++ b/nl/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/nl/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/nl/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/nl/index.md b/nl/index.md
new file mode 100644
index 0000000000..b556b6e21b
--- /dev/null
+++ b/nl/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Kom meer te weten.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/nl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/nl/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/nl/why)
+
+## Gefinancierd door zijn gebruikers
+
+Om onafhankelijk te blijven, zullen grote kanalen en gemeenschappen voor hun servers betalen.
+
+En gebruikers kunnen nu investeren in SimpleX Chat — de crowdfunding is live!
+
+[Investeer in SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/nl/invitation.md b/nl/invitation.md
new file mode 100644
index 0000000000..34031009e6
--- /dev/null
+++ b/nl/invitation.md
@@ -0,0 +1,66 @@
+# Je hebt een eenmalige link ontvangen om verbinding te maken met SimpleX Chat
+
+## Scan de QR-code met de SimpleX Chat app op je telefoon of tablet.
+
+De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina — ze zijn opgenomen in het hash-fragment van de link-URL.
+
+Heb je de SimpleX Chat nog niet gedownload?
+
+Gebruik onderstaande links om de app te downloaden.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan de QR-code van de mobiele app
+
+# Je hebt een eenmalige link ontvangen om verbinding te maken met SimpleX Chat
+
+Om een verbinding te maken:
+
+Installeer de SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid)
+
+1
+
+Maak verbinding met de app
+
+Open de Simplex app
+
+2
+
+Tik op de knop 'verbinden' in de app
+
+3
+
+## Scan de QR-code met de SimpleX Chat app
+
+De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina bekijkt -
+ze zijn opgenomen in het hash-fragment van de link-URL.
+
+## SimpleX chat installeren op terminal
+
+Gebruik deze opdracht:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Zie SimpleX chat GitHub repository voor instructies over hoe u deze kunt downloaden of compileren vanuit de broncode.
+
+---
+
+## Als u SimpleX Chat al voor de terminal hebt geïnstalleerd
+
+Als u al hebt geïnstalleerd SimpleX Chat voor de terminal v1.0.0+, kopieer de onderstaande opdracht en gebruik deze in de chat:
+
+## Word lid van SimpleX
+
+Wij nodigen u uit om deel te nemen aan de conversatie
+
+[Bezoek ons op REDDIT](https://www.reddit.com/r/SimpleXChat/) [Volg ons op GitHub](https://github.com/simplex-chat) [Doneer hier om ons te helpen](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Schrijf u in om onze updates te ontvangen
+
+---
+
+Verkrijg SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/nl/fdroid)
diff --git a/nl/invitation/index.html b/nl/invitation/index.html
index 267bb2eba8..f14e213123 100644
--- a/nl/invitation/index.html
+++ b/nl/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Je hebt een eenmalige link ontvangen om verbinding te maken met SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan de QR-code met de SimpleX Chat app op je telefoon of tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina — ze zijn opgenomen in het hash-fragment van de link-URL.
+                De openbare sleutels en het berichten wachtrij adres in deze link worden NIET over het netwerk verzonden wanneer u deze pagina &mdash; ze zijn opgenomen in het hash-fragment van de link-URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Heb je de SimpleX Chat nog niet gedownload?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Gebruik onderstaande links om de app te downloaden.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Installeer de SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Tik op de knop <span class="text-active-blue">'verbinden'</span> in de app</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Tik op de knop <span class='text-active-blue'>'verbinden'</span> in de app</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan de QR-code met de SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX chat installeren op terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
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@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Als u SimpleX Chat al voor de terminal hebt geïnstalleerd</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
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+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
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@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Schrijf u in om onze updates te ontvangen</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Voer uw e-mail adres in">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Verkrijg SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/nl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/nl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/messaging.md b/nl/messaging.md
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--- /dev/null
+++ b/nl/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Waarom is SimpleX uniek
+
+### U heeft volledige privacy
+
+SimpleX beschermt de privacy van uw profiel, contacten en metagegevens door deze te verbergen voor de netwerkservers van SimpleX en andere buitenstaanders.
+
+In tegenstelling tot andere bestaande berichtennetwerken worden bij SimpleX geen identificatiegegevens aan de gebruikers toegewezen – **zelfs geen willekeurige getallen**.
+
+### U bent beschermd tegen spam en misbruik
+
+Omdat u geen identificatiecode of vast adres hebt op het SimpleX-netwerk, kan niemand contact met u opnemen, tenzij u een eenmalig of tijdelijk gebruikersadres deelt in de vorm van een QR-code of een link.
+
+### U beheert uw gegevens
+
+SimpleX slaat alle gebruikersgegevens op client apparaten op in een **draagbaar gecodeerd databaseformaat** — en kan worden overgedragen naar een ander apparaat.
+
+De end-to-end versleutelde berichten worden tijdelijk op SimpleX relayservers bewaard totdat ze zijn ontvangen, waarna ze permanent worden verwijderd.
+
+### U bent eigenaar van het SimpleX netwerk
+
+Het SimpleX-netwerk is volledig gedecentraliseerd en onafhankelijk van welke cryptovaluta dan ook of enig ander netwerk, met uitzondering van het internet.
+
+U kunt SimpleX  **gebruiken met uw eigen servers**  of met de servers die door ons worden geleverd — en toch verbinding maken met elke gebruiker.
+
+# Volledige privacy van uw identiteit, profiel, contacten en metadata
+
+In tegenstelling tot andere berichtennetwerken heeft SimpleX geen identificatiegegevens toegewezen aan de gebruikers. Het maakt geen gebruik van telefoonnummers, domeingebaseerde adressen (zoals e-mail of XMPP), gebruikersnamen, openbare sleutels of zelfs willekeurige getallen om gebruikers te identificeren – SimpleX-serverbeheerders weten niet hoeveel mensen hun servers gebruiken.
+
+Om berichten af te leveren gebruikt SimpleX [paarsgewijze anonieme adressen](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) van unidirectionele berichten wachtrijen, gescheiden voor ontvangen en verzonden berichten, meestal via verschillende servers.
+
+Dit ontwerp beschermt de privacy van uw communicatiepartner door deze te verbergen voor SimpleX-netwerkservers en andere buitenstaanders. Om uw IP-adres voor de servers te verbergen, kunt u **via Tor verbinding maken met SimpleX-servers**.
+
+# De beste bescherming tegen spam en misbruik
+
+Omdat u geen identificatiegegevens hebt op het SimpleX-netwerk, kan niemand contact met u opnemen, tenzij u een eenmalig of tijdelijk gebruikersadres deelt in de vorm van een QR-code of een link.
+
+Zelfs met het optionele gebruikers adres, hoewel het kan worden gebruikt om spam-contact verzoeken te verzenden, kunt u het wijzigen of volledig verwijderen zonder uw verbindingen te verliezen.
+
+# Eigendom, controle en beveiliging van uw gegevens
+
+SimpleX Chat slaat alle gebruikersgegevens alleen op client apparaten op met behulp van een **draagbaar gecodeerd databaseformaat** dat kan worden geëxporteerd en overgebracht naar elk ondersteund apparaat.
+
+De end-to-end versleutelde berichten worden tijdelijk op SimpleX relayservers bewaard totdat ze zijn ontvangen, waarna ze permanent worden verwijderd.
+
+In tegenstelling tot gefedereerde netwerkservers (e-mail, XMPP of Matrix), slaan SimpleX servers geen gebruikers account op, ze sturen alleen berichten door, waardoor de privacy van beide partijen wordt beschermd.
+
+Er zijn geen identifiers of gecodeerde tekst tussen verzonden en ontvangen serververkeer — als iemand het waarneemt, kunnen ze niet gemakkelijk bepalen wie met wie communiceert, zelfs als TLS is gecompromitteerd.
+
+# Volledig gedecentraliseerd — gebruikers zijn eigenaar van het SimpleX netwerk
+
+U kunt **SimpleX gebruiken met uw eigen servers** en toch communiceren met mensen die de servers gebruiken die vooraf in de apps zijn geconfigureerd.
+
+SimpleX Network maakt gebruik van een [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) en biedt [SDK om chatbots te maken](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript). Dit maakt de implementatie van services mogelijk waarmee gebruikers via SimpleX Chat-apps kunnen communiceren. We zijn erg benieuwd welke SimpleX-services jullie gaan bouwen.
+
+Als u overweegt om voor het SimpleX-netwerk te ontwikkelen, bijvoorbeeld de chatbot voor SimpleX-appgebruikers of de integratie van de SimpleX Chat-bibliotheek in uw mobiele apps, neem dan [contact](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) op voor advies en ondersteuning.
+
+## Functies
+
+E2E-versleutelde berichten met markdown en bewerking
+
+E2E-versleutelde
+afbeeldingen,videos en bestanden
+
+E2E-gecodeerde gedecentraliseerde groepen - alleen gebruikers weten dat ze bestaan
+
+E2E-versleutelde spraakberichten
+
+Verdwijnende geheime gesprekken
+
+E2E-versleutelde
+audio- en videogesprekken
+
+Draagbare gecodeerde app-opslag - profiel naar een ander apparaat verplaatsen
+
+Incognitomodus -
+uniek voor SimpleX Chat
+
+## Wat maakt SimpleX privé
+
+### Tijdelijke anonieme paarsgewijze identifiers
+
+SimpleX gebruikt tijdelijke anonieme paarsgewijze adressen en inloggegevens voor elk gebruikers contact of groepslid.
+
+Het maakt het mogelijk om berichten te bezorgen zonder gebruikers profiel-ID's, wat een betere privacy van metagegevens biedt dan alternatieven.
+
+### Out-of-band sleuteluitwisseling
+
+Veel communicatienetwerken zijn kwetsbaar voor MITM-aanvallen door servers of netwerkaanbieders.
+
+Om te voorkomen dat SimpleX apps eenmalige sleutels out-of-band doorgeven, wanneer u een adres deelt als een link of een QR-code.
+
+### 2 lagen end-to-end versleuteling
+
+Protocol met double-ratchet -
+OTR-berichten met perfecte voorwaartse geheimhouding en inbraak herstel.
+
+NaCL-cryptobox in elke wachtrij om verkeer correlatie tussen berichten wachtrijen te voorkomen als TLS wordt aangetast.
+
+### Bericht integriteit verificatie
+
+Om de integriteit te garanderen, zijn de berichten opeenvolgend genummerd en bevatten ze de hash van het vorige bericht.
+
+Als een bericht wordt toegevoegd, verwijderd of gewijzigd, wordt de ontvanger gewaarschuwd.
+
+### Extra laag server versleuteling
+
+Extra server versleuteling laag voor levering aan de ontvanger, om de correlatie tussen ontvangen en verzonden server verkeer te voorkomen als TLS is aangetast.
+
+### Berichten mixen om correlatie te verminderen
+
+SimpleX servers fungeren als mix nodes met lage latentie — de inkomende en uitgaande berichten hebben een andere volgorde.
+
+### Veilig geverifieerd TLS-transport
+
+Alleen TLS 1.2/1.3 met sterke algoritmen wordt gebruikt voor client-server verbindingen.
+
+Server fingerprint en channel binding voorkomen MITM- en replay-aanvallen.
+
+Connectie herstel is uitgeschakeld om sessie aanvallen te voorkomen.
+
+### Optionele toegang via Tor
+
+Om uw IP-adres te beschermen kunt u via Tor of een ander transport overlay netwerk toegang krijgen tot de servers.
+
+Installeer de [Orbot-app](https://guardianproject.info/apps/org.torproject.android/) en schakel de SOCKS5-proxy in (of VPN [op iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)) om SimpleX via Tor te gebruiken.
+
+### Unidirectionele berichtenwachtrijen
+
+Elke berichten wachtrij geeft berichten in één richting door, met verschillende verzend en ontvangst adressen.
+
+Het vermindert de aanvals mogenlijkheden, in vergelijking met traditionele berichten diensten en de beschikbare metadata.
+
+### Meerdere lagen van inhouds opvulling
+
+SimpleX gebruikt content opvulling voor elke coderingslaag om aanvallen op bericht grootte te verstoren.
+
+Het zorgt ervoor dat berichten van verschillende grootte er hetzelfde uitzien voor de servers en netwerk waarnemers.
+
+## SimpleX Netwerk
+
+SimpleX Chat biedt de beste privacy door de voordelen van P2P en gefedereerde netwerken te combineren.
+
+### In tegenstelling tot P2P netwerken
+
+Alle berichten worden verzonden via servers, die zorgen voor een betere metadata privacy en een betrouwbare asynchrone bezorging van berichten, terwijl er veel word vermeden .
+
+# Vergelijking met P2P berichten protocollen
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer)-berichtenprotocollen en -apps hebben verschillende problemen waardoor ze minder betrouwbaar zijn dan SimpleX, complexer om te analyseren en kwetsbaarder voor verschillende soorten aanvallen.
+
+1. P2P netwerken vertrouwen op een variant van [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) om berichten te routeren. DHT ontwerpen moeten een balans vinden tussen leveringsgarantie en latentie. SimpleX heeft zowel een betere leveringsgarantie als een lagere latentie dan P2P, omdat het bericht redundant via meerdere servers parallel kan worden doorgegeven, met behulp van de servers die door de ontvanger zijn gekozen. In P2P netwerken wordt het bericht achtereenvolgens door *O(log N)*-knooppunten geleid, met behulp van door het algoritme gekozen knooppunten.
+2. SimpleX ontwerp heeft, in tegenstelling tot de meeste P2P netwerken, geen globale gebruikers-ID's van welke soort dan ook, zelfs niet tijdelijk en gebruikt alleen tijdelijke paarsgewijze ID's wat een betere anonimiteit en metadata bescherming biedt.
+3. P2P lost het probleem [MITM-aanval](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) niet op en de meeste bestaande implementaties gebruiken geen out-of-band berichten voor de initiële sleuteluitwisseling. SimpleX gebruikt out-of-band berichten of, in sommige gevallen, reeds bestaande veilige en vertrouwde verbindingen voor de eerste sleuteluitwisseling.
+4. P2P-implementaties kunnen door sommige internetproviders worden geblokkeerd (zoals [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport-agnostisch – het kan werken via standaard webprotocollen, zoals WebSockets.
+5. Alle bekende P2P netwerken kunnen kwetsbaar zijn voor [Sybil-aanval](https://en.wikipedia.org/wiki/Sybil_attack), omdat elk knooppunt vindbaar is en het netwerk als een geheel opereert. Bekende maatregelen om het te verminderen, vereisen een gecentraliseerde component of duur [bewijs van werk](https://en.wikipedia.org/wiki/Proof_of_work). Het SimpleX-netwerk kan niet worden gedetecteerd door de server, het is gefragmenteerd en werkt als meerdere geïsoleerde subnetwerken, waardoor netwerkbrede aanvallen onmogelijk zijn.
+6. P2P netwerken kunnen kwetsbaar zijn voor [DRDoS-aanvallen](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), wanneer de clients het verkeer opnieuw kunnen uitzenden en versterken, wat resulteert in netwerkbrede denial of service. SimpleX clients sturen alleen verkeer van een bekende verbinding door en kunnen niet door een aanvaller worden gebruikt om het verkeer in het hele netwerk te versterken.
+
+---
+
+### In tegenstelling tot federatieve netwerken
+
+SimpleX relay servers slaan GEEN gebruikers profielen, contacten en afgeleverde berichten op, maken GEEN verbinding met elkaar en er is GEEN server directory.
+
+---
+
+### SimpleX netwerk
+
+servers bieden unidirectionele wachtrijen om de gebruikers te verbinden, maar ze hebben geen zicht op de netwerk verbindings grafiek — alleen de gebruikers.
+
+## SimpleX uitgelegd
+
+1. Wat gebruikers ervaren
+
+2. Hoe werkt het
+
+3. Wat servers zien
+
+1. Wat gebruikers ervaren
+
+U kunt contacten en groepen maken en tweerichtings gesprekken voeren, zoals in elke andere messenger.
+
+Hoe kan het werken met unidirectionele wachtrijen en zonder gebruikers profiel-ID's?
+
+2. Hoe werkt het
+
+Voor elke verbinding gebruikt u twee afzonderlijke berichten wachtrijen om berichten via verschillende servers te verzenden en te ontvangen.
+
+Servers geven berichten slechts in één richting door, zonder een volledig beeld te hebben van het gesprek of de connecties van de gebruiker.
+
+3. Wat servers zien
+
+De servers hebben afzonderlijke anonieme inloggegevens voor elke wachtrij en weten niet tot welke gebruikers ze behoren.
+
+Gebruikers kunnen de privacy van metadata verder verbeteren door Tor te gebruiken om toegang te krijgen tot servers, waardoor corellatie op IP-adres wordt voorkomen.
+
+## Vergelijking met andere protocollen
+
+|  |  | Signaal, grote platforms | XMPP, Matrix | P2P protocollen |
+| --- | --- | --- | --- | --- |
+| Vereist globale identiteit | Nee - privé | Ja [1] | Ja [2] | Ja [3] |
+| Mogelijkheid van MITM | Nee - veilig [4] | Ja [5] | Ja | Ja |
+| Afhankelijkheid van DNS | Nee - veerkrachtig | Ja | Ja | Nee |
+| Enkelvoudig of gecentraliseerd netwerk | Nee - gedecentraliseerd | Ja | Nee - gefedereerd [6] | Ja [7] |
+| Centrale component of andere netwerkbrede aanval | Nee - veerkrachtig | Ja | Ja [2] | Ja [8] |
+
+---
+
+1. Meestal op basis van een telefoonnummer, in sommige gevallen op gebruikersnamen
+2. Op DNS gebaseerde adressen
+3. Publieke sleutel of een andere globale unieke ID
+4. SimpleX relais kunnen de e2e-versleuteling niet in gevaar brengen. Controleer de beveiligingscode om aanvallen op out-of-band kanalen te beperken
+5. Als de servers van de operator zijn gecompromitteerd. Controleer de beveiligingscode in Signal en enkele andere apps om dit te beperken
+6. Beschermt de privacy van metagegevens van gebruikers niet
+7. Hoewel P2P gedistribueerd is, is het niet gefedereerd — het functioneert als één enkel netwerk.
+8. P2P netwerken hebben een centrale autoriteit of het hele netwerk kan worden aangetast — [kijk hier](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [kijk hier](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/nl/messaging/index.html b/nl/messaging/index.html
index f23375ac6b..9b196f9fb2 100644
--- a/nl/messaging/index.html
+++ b/nl/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U heeft volledige privacy</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U bent beschermd<br>tegen spam en misbruik</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U beheert uw gegevens</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U bent eigenaar van het SimpleX netwerk</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Het maakt het mogelijk om berichten te bezorgen zonder gebruikers profiel-ID's, wat een betere privacy van metagegevens biedt dan alternatieven.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Om te voorkomen dat SimpleX apps eenmalige sleutels out-of-band doorgeven, wanneer u een adres deelt als een link of een QR-code.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL-cryptobox in elke wachtrij om verkeer correlatie tussen berichten wachtrijen te voorkomen als TLS wordt aangetast.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Als een bericht wordt toegevoegd, verwijderd of gewijzigd, wordt de ontvanger gewaarschuwd.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Extra server versleuteling laag voor levering aan de ontvanger, om de correlatie tussen ontvangen en verzonden server verkeer te voorkomen als TLS is aangetast.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers fungeren als mix nodes met lage latentie — de inkomende en uitgaande berichten hebben een andere volgorde.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connectie herstel is uitgeschakeld om sessie aanvallen te voorkomen.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Installeer de <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot-app </a> en schakel de SOCKS5-proxy in (of VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank"> op iOS </a>) om SimpleX via Tor te gebruiken.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Het vermindert de aanvals mogenlijkheden, in vergelijking met traditionele berichten diensten en de beschikbare metadata.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Het zorgt ervoor dat berichten van verschillende grootte er hetzelfde uitzien voor de servers en netwerk waarnemers.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tik om te sluiten</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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diff --git a/nl/old/index.html b/nl/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U heeft volledige privacy</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U bent beschermd<br>tegen spam en misbruik</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U beheert uw gegevens</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">U bent eigenaar van het SimpleX netwerk</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/nl/why.md b/nl/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/nl/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/nl/why/index.html b/nl/why/index.html
index 77b1bcf15b..8ced753e67 100644
--- a/nl/why/index.html
+++ b/nl/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/nl/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/old/index.html b/old/index.html
index a6b1540e8f..d7be2204e6 100644
--- a/old/index.html
+++ b/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-anonymous-credentials" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Anonymous credentials</h4><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="anonymous-credentials">Read more</button></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/contact.md b/pl/contact.md
new file mode 100644
index 0000000000..d1da7a7761
--- /dev/null
+++ b/pl/contact.md
@@ -0,0 +1,66 @@
+# Otrzymałeś adres do połączenia na SimpleX Chat
+
+## Zeskanuj kod QR za pomocą aplikacji SimpleX Chat na swoim telefonie lub tablecie.
+
+Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę — są one zawarte w linku we fragmencie hash adresu URL.
+
+Nie pobrałeś jeszcze SimpleX Chat?
+
+Skorzystaj z poniższych linków, aby pobrać aplikację.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Zeskanuj kod QR z aplikacji mobilnej
+
+# Otrzymałeś adres do połączenia na SimpleX Chat
+
+Aby nawiązać połączenie:
+
+Zainstaluj aplikację SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid)
+
+1
+
+Połącz się w aplikacji
+
+Otwórz aplikację Simplex
+
+2
+
+Stuknij przycisk "połącz się" w aplikacji
+
+3
+
+## Zeskanuj kod QR za pomocą aplikacji SimpleX Chat
+
+Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony —
+są one zawarte w linku we fragmencie hash adresu URL.
+
+## Instalacja SimpleX Chat do terminala
+
+Użyj tego polecenia:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Zobacz SimpleX Chat Repozytorium GitHub instrukcje jak to pobrać lub skompilować z kodu źródłowego.
+
+---
+
+## Jeśli zainstalowałeś już SimpleX Chat dla terminala
+
+Jeśli już zainstalowałeś SimpleX Chat dla terminala v1.0.0+, skopiuj poniższe polecenie i użyj go na czacie:
+
+## Dołącz do SimpleX
+
+Zapraszamy do udziału w rozmowie
+
+[Dołącz do społeczności REDDIT](https://www.reddit.com/r/SimpleXChat/) [Dołącz do nas na GitHubie](https://github.com/simplex-chat) [Przekaż darowiznę tutaj, aby nam pomóc](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Zapisz się, aby otrzymywać nasze aktualizacje
+
+---
+
+Pobierz SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid)
diff --git a/pl/contact/index.html b/pl/contact/index.html
index 0a0754838f..9661928e9f 100644
--- a/pl/contact/index.html
+++ b/pl/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Otrzymałeś adres do połączenia na SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Zeskanuj kod QR za pomocą aplikacji SimpleX Chat na swoim telefonie lub tablecie.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę — są one zawarte w linku we fragmencie hash adresu URL.
+                Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę &mdash; są one zawarte w linku we fragmencie hash adresu URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Nie pobrałeś jeszcze SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Skorzystaj z poniższych linków, aby pobrać aplikację.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Zainstaluj aplikację SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Zeskanuj kod QR za pomocą aplikacji SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony —<br> są one zawarte w linku we fragmencie hash adresu URL.
+                            Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony &mdash;<br> są one zawarte w linku we fragmencie hash adresu URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalacja SimpleX Chat do terminala</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repozytorium GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jeśli zainstalowałeś już SimpleX Chat dla terminala</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Zapisz się, aby otrzymywać nasze aktualizacje</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Wpisz swój adres e-mail">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Pobierz SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/fdroid.md b/pl/fdroid.md
new file mode 100644
index 0000000000..94faf536ed
--- /dev/null
+++ b/pl/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat na F-Droid
+
+### Repo SimpleX
+
+Wersje stabilne i beta zbudowane przez deweloperów
+
+Aby dodać do Twojego klienta F-Droid, zeskanuj kod QR lub użyj tego URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Odcisk klucza podpisu (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Repo F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Wersje stabilne zbudowane przez F-Droid.org
+
+Wydania na tym repo są kilka dni później.
+
+Repozytoria SimpleX Chat i F-Droid.org mają podpisane budowy z innymi kluczami. Aby zmienić, proszę [wyeksportuj](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) bazę czatu i przeinstaluj aplikację.
diff --git a/pl/fdroid/index.html b/pl/fdroid/index.html
index e24595ce92..701f78535a 100644
--- a/pl/fdroid/index.html
+++ b/pl/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat na F-Droid</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Wersje stabilne i beta zbudowane przez deweloperów</p>
                         <p>Aby dodać do Twojego klienta F-Droid, <span class="hide-on-mobile">zeskanuj kod QR lub</span> użyj tego URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Odcisk klucza podpisu (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Repo F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Wersje stabilne zbudowane przez F-Droid.org</p>
                 <p class="mb-2">Wydania na tym repo są kilka dni później.</p>
                 <p class="mb-2">Repozytoria SimpleX Chat i F-Droid.org mają podpisane budowy z innymi kluczami. Aby zmienić, proszę <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">wyeksportuj</a> bazę czatu i przeinstaluj aplikację.</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/file.md b/pl/file.md
new file mode 100644
index 0000000000..6d5683d3d2
--- /dev/null
+++ b/pl/file.md
@@ -0,0 +1,31 @@
+# Transfer plików SimpleX
+
+Przeciągnij i upuść plik tutaj
+
+lub
+
+Wybierz plik
+
+Maksymalnie 100 MB - [aplikacja SimpleX Chat](https://simplex.chat/downloads) obsługuje pliki o rozmiarze do 1 GB
+
+Wysyłaj pliki bezpiecznie dzięki szyfrowaniu typu end-to-end — bez kont, bez śledzenia.
+
+## Pobierz SimpleX Chat — najbezpieczniejszy i najbardziej prywatny komunikator
+
+Przesyłanie plików, z którego właśnie skorzystałeś, wykorzystuje ten sam protokół routingu danych, co SimpleX Chat. Aplikacja oferuje szyfrowane wiadomości, połączenia głosowe i wideo, grupy oraz wysyłanie plików. Bez konta. Bez telefonu. Bez adresu e-mail. Bez identyfikatorów profilu użytkownika.
+
+# Protokół XFTP: najbezpieczniejszy transfer plików
+
+### Nie jest wymagane konto
+
+Każdy fragment pliku wykorzystuje nowy losowy klucz. Routery danych nie mają „użytkowników” ani „plików” – przesyłają zaszyfrowane fragmenty plików o stałych rozmiarach.
+
+### Potrójne szyfrowanie w przeglądarce
+
+Klucz szyfrowania plików znajduje się wyłącznie we fragmencie skrótu adresu URL – przeglądarka nigdy nie wysyła go do serwera. Istnieją trzy warstwy szyfrowania: transport TLS, szyfrowanie po-odbiorcy (unikalny klucz tymczasowy dla każdego transferu) oraz szyfrowanie plików typu end-to-end.
+
+### Niezależne routery danych
+
+Gdy plik jest dzielony na fragmenty, jest on wysyłany przez routery sieciowe obsługiwane przez niezależne podmioty. Żaden operator nie może zobaczyć rzeczywistego rozmiaru ani nazwy pliku. Nawet jeśli router zostanie naruszony, może on zobaczyć tylko zaszyfrowane fragmenty o stałym rozmiarze. Fragmenty plików są przechowywane w pamięci podręcznej routerów sieciowych przez około 48 godzin.
+
+[Zapoznaj się ze specyfikacją protokołu XFTP →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/pl/file/index.html b/pl/file/index.html
index 8b71f684dc..3db71dc844 100644
--- a/pl/file/index.html
+++ b/pl/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">Transfer plików SimpleX</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>Przeciągnij i upuść plik tutaj</p>
@@ -699,11 +706,11 @@ window.addEventListener('click',(e)=>{
       Przesyłanie plików, z którego właśnie skorzystałeś, wykorzystuje ten sam protokół routingu danych, co SimpleX Chat. Aplikacja oferuje szyfrowane wiadomości, połączenia głosowe i wideo, grupy oraz wysyłanie plików. Bez konta. Bez telefonu. Bez adresu e-mail. Bez identyfikatorów profilu użytkownika.
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/pl/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/pl/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/index.html b/pl/index.html
index 89ea860095..ed6fc22cf4 100644
--- a/pl/index.html
+++ b/pl/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/pl/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/pl/fdroid" title="SimpleX app z F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-wydanie na TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-wydanie na TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Audyty Bezpieczeństwa" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Teraz</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Cze 2027</span>
diff --git a/pl/index.md b/pl/index.md
new file mode 100644
index 0000000000..92875aa650
--- /dev/null
+++ b/pl/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Bądź Wolny
+
+## W Swojej Sieci
+
+Pierwsza sieć bez identyfikatorów użytkowników.
+Twoje kontakty, grupy i kanały należą do Ciebie.
+
+Invest in SimpleX Chat. [Dowiedz się więcej.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app z F-Droid](https://simplex.chat/pl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Audyty Bezpieczeństwa](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Audyty
+Bezpieczeństwa
+
+[Wskazówki dotyczące prywatności – zalecenia dotyczące komunikatorów](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Rekomendowane komunikatory przez Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publikacje Online Heise](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Recenzja od Mike'a Kuketz'a](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Wywiad w formie podcastu od OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nikt Nie Widzi Z Kim Rozmawiasz
+
+Nawet serwery nie widzą – wszystkie wiadomości wyglądają jak losowy szum.
+
+Dziesiątki milionów wiadomości dostarczanych prywatnie każdego dnia.
+
+[Dowiedz się więcej o komunikatorze SimpleX](https://simplex.chat/pl/messaging)
+
+## Sieć Należy Do Ciebie
+
+Każdy kontakt i grupa znajduje się na Twoim urządzeniu, a nie w bazie danych serwera.
+
+Żaden podmiot nie kontroluje sieci – każdy może uruchomić serwer.
+
+[Dlaczego to budujemy](https://simplex.chat/pl/why)
+
+## Finansowane Przez Użytkowników
+
+Aby zachować niezależność, duże kanały i społeczności będą opłacać swoje serwery.
+
+A użytkownicy mogą teraz inwestować w SimpleX Chat — crowdfunding wystartował!
+
+[Zainwestuj w SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Plan Działania SimpleX dla Wolnego Internetu
+
+2026
+
+: Wyskalowany dla Dużych Społeczności
+
+Wymyka się scentralizowanym platformom
+
+Cze 2027
+
+: Zrównoważone Społeczności i Serwery
+
+Uruchomienie Community Credits
+
+Gru 2027
+
+: Spraw, aby Twoje społeczności Rosły
+
+Narzędzia do promowania Twoich społeczności
+
+[Grupa użytkowników SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Dołącz do Społeczności SimpleX
+
+Ponad 2 miliony osób pobrało aplikacje SimpleX.
+
+Znajdź swoje kanały i społeczności w katalogu i stwórz własne!
+
+[Zobacz katalog SimpleX](https://simplex.chat/directory)
diff --git a/pl/invitation.md b/pl/invitation.md
new file mode 100644
index 0000000000..ed3876ee26
--- /dev/null
+++ b/pl/invitation.md
@@ -0,0 +1,66 @@
+# Otrzymałeś jednorazowy link do połączenia na SimpleX Chat
+
+## Zeskanuj kod QR za pomocą aplikacji SimpleX Chat na swoim telefonie lub tablecie.
+
+Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę — są one zawarte w linku we fragmencie hash adresu URL.
+
+Nie pobrałeś jeszcze SimpleX Chat?
+
+Skorzystaj z poniższych linków, aby pobrać aplikację.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Zeskanuj kod QR z aplikacji mobilnej
+
+# Otrzymałeś jednorazowy link do połączenia na SimpleX Chat
+
+Aby nawiązać połączenie:
+
+Zainstaluj aplikację SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid)
+
+1
+
+Połącz się w aplikacji
+
+Otwórz aplikację Simplex
+
+2
+
+Stuknij przycisk "połącz się" w aplikacji
+
+3
+
+## Zeskanuj kod QR za pomocą aplikacji SimpleX Chat
+
+Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony —
+są one zawarte w linku we fragmencie hash adresu URL.
+
+## Instalacja SimpleX Chat do terminala
+
+Użyj tego polecenia:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Zobacz SimpleX Chat Repozytorium GitHub instrukcje jak to pobrać lub skompilować z kodu źródłowego.
+
+---
+
+## Jeśli zainstalowałeś już SimpleX Chat dla terminala
+
+Jeśli już zainstalowałeś SimpleX Chat dla terminala v1.0.0+, skopiuj poniższe polecenie i użyj go na czacie:
+
+## Dołącz do SimpleX
+
+Zapraszamy do udziału w rozmowie
+
+[Dołącz do społeczności REDDIT](https://www.reddit.com/r/SimpleXChat/) [Dołącz do nas na GitHubie](https://github.com/simplex-chat) [Przekaż darowiznę tutaj, aby nam pomóc](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Zapisz się, aby otrzymywać nasze aktualizacje
+
+---
+
+Pobierz SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pl/fdroid)
diff --git a/pl/invitation/index.html b/pl/invitation/index.html
index aff805b49e..a85ae09f73 100644
--- a/pl/invitation/index.html
+++ b/pl/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Otrzymałeś jednorazowy link do połączenia na SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Zeskanuj kod QR za pomocą aplikacji SimpleX Chat na swoim telefonie lub tablecie.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę — są one zawarte w linku we fragmencie hash adresu URL.
+                Klucze publiczne i adres kolejki wiadomości w tym linku NIE są przesyłane przez sieć, gdy oglądasz tę stronę &mdash; są one zawarte w linku we fragmencie hash adresu URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Nie pobrałeś jeszcze SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Skorzystaj z poniższych linków, aby pobrać aplikację.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Zainstaluj aplikację SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Zeskanuj kod QR za pomocą aplikacji SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony —<br> są one zawarte w linku we fragmencie hash adresu URL.
+                            Klucze publiczne i adres kolejki wiadomości w tym linku NIE są wysyłane przez sieć podczas przeglądania tej strony &mdash;<br> są one zawarte w linku we fragmencie hash adresu URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalacja SimpleX Chat do terminala</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repozytorium GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Jeśli zainstalowałeś już SimpleX Chat dla terminala</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Zapisz się, aby otrzymywać nasze aktualizacje</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Wpisz swój adres e-mail">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Pobierz SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/pl/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/pl/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/messaging.md b/pl/messaging.md
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--- /dev/null
+++ b/pl/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Dlaczego SimpleX jest unikalny
+
+### Masz pełną prywatność
+
+SimpleX chroni prywatność Twojego profilu, kontaktów i metadanych, ukrywając je przed serwerami sieci SimpleX i wszelkimi obserwatorami.
+
+W przeciwieństwie do każdej innej istniejącej sieci komunikacyjnej, SimpleX nie ma żadnych identyfikatorów przypisanych do użytkowników — **nawet losowych liczb**.
+
+### Jesteś chroniony przed spamem i nadużyciami
+
+Ponieważ w sieci SimpleX nie masz identyfikatora ani stałego adresu, nikt nie może się z Tobą skontaktować, chyba że udostępnisz jednorazowy lub tymczasowy adres użytkownika, w postaci kodu QR lub linku.
+
+### Masz kontrolę nad swoimi danymi
+
+SimpleX przechowuje wszystkie dane użytkownika na urządzeniach klienckich w formacie **przenośnej zaszyfrowanej bazy danych** — można je przenieść na inne urządzenie.
+
+Wiadomości zaszyfrowane end-to-end są przechowywane tymczasowo na serwerach przekaźnikowych SimpleX do momentu ich odebrania, po czym są trwale usuwane.
+
+### Jesteś właścicielem sieci SimpleX
+
+Sieć SimpleX jest w pełni zdecentralizowana i niezależna od jakiejkolwiek krypto-waluty lub jakiejkolwiek innej sieci, poza Internetem.
+
+Możesz **używać SimpleX z własnymi serwerami** lub z serwerami dostarczonymi przez nas — i nadal łączyć się z dowolnym użytkownikiem.
+
+# Pełna prywatność Twojej tożsamości, profilu, kontaktów i metadanych
+
+W przeciwieństwie do innych sieci komunikacyjnych, SimpleX ma **brak identyfikatorów przypisanych do użytkowników**. Nie polega na numerach telefonów, adresach opartych na domenie (jak e-mail lub XMPP), nazwach użytkowników, kluczach publicznych czy nawet losowych liczbach, aby zidentyfikować swoich użytkowników — operatorzy serwerów SimpleX nie wiedzą, ile osób korzysta z ich serwerów.
+
+Do dostarczania wiadomości SimpleX używa [parami anonimowych adresów](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) jednokierunkowych kolejek z wiadomościami, oddzielnych dla wiadomości odbieranych i wysyłanych, zwykle przez różne serwery.
+
+Taka konstrukcja chroni prywatność tego, z kim się komunikujesz, ukrywając ją przed serwerami sieci SimpleX i przed wszelkimi obserwatorami. Aby ukryć swój adres IP przed serwerami, możesz **połączyć się z serwerami SimpleX za pośrednictwem sieci Tor**.
+
+# Najlepsza ochrona przed spamem i nadużyciami
+
+Ponieważ nie masz identyfikatora w sieci SimpleX, nikt nie może się z Tobą skontaktować, chyba że udostępnisz jednorazowy lub tymczasowy adres użytkownika, w postaci kodu QR lub linku.
+
+Nawet w przypadku opcjonalnego adresu użytkownika, podczas gdy może on być używany do wysyłania spamowych zapytań o kontakt, możesz go zmienić lub całkowicie usunąć bez utraty jakichkolwiek połączeń.
+
+# Własność, kontrola i bezpieczeństwo Twoich danych
+
+SimpleX Chat przechowuje wszystkie dane użytkowników tylko na urządzeniach klienckich przy użyciu **przenośnego formatu zaszyfrowanej bazy danych**, który można wyeksportować i przenieść na dowolne obsługiwane urządzenie.
+
+Wiadomości zaszyfrowane end-to-end są przechowywane tymczasowo na serwerach przekaźnikowych SimpleX do momentu ich odebrania, po czym są trwale usuwane.
+
+W przeciwieństwie do serwerów sieci federacyjnych (e-mail, XMPP czy Matrix), serwery SimpleX nie przechowują kont użytkowników, a jedynie przekazują wiadomości, chroniąc prywatność obu stron.
+
+Nie ma żadnych identyfikatorów ani szyfrogramów wspólnych między wysyłanym i odbieranym ruchem serwera — jeśli ktokolwiek to obserwuje, nie może łatwo określić, kto komunikuje się z kim, nawet jeśli bezpieczeństwo protokołu TLS zostało zagrożone.
+
+# W pełni zdecentralizowana — użytkownicy są właścicielami sieci SimpleX
+
+Możesz **używać SimpleX z własnymi serwerami** i nadal komunikować się z osobami, które korzystają z prekonfigurowanych w aplikacji serwerów.
+
+Sieć SimpleX wykorzystuje [otwarty protokół](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) i udostępnia [SDK do tworzenia chatbotów](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), umożliwiając implementację usług, z którymi użytkownicy mogą wchodzić w interakcje za pośrednictwem aplikacji SimpleX Chat — naprawdę nie możemy się doczekać, aby zobaczyć, jakie usługi SimpleX zbudujesz.
+
+Jeśli rozważasz rozwój dla sieci SimpleX, na przykład czatbotu dla użytkowników aplikacji SimpleX lub integrację biblioteki SimpleX Chat w swoich aplikacjach mobilnych, prosimy o [kontakt](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) dla wszelkich porad i wsparcia.
+
+## Funkcje
+
+Wiadomości szyfrowane przez E2E ze składnią markdown i edycją
+
+Obrazy, wideo i pliki
+zaszyfrowane przez E2E
+
+Zaszyfrowane E2E zdecentralizowane grupy — tylko użytkownicy wiedzą, że te grupy istnieją
+
+Wiadomości głosowe zaszyfrowane przez E2E
+
+Znikające wiadomości
+
+Połączenia audio i wideo
+szyfrowane przez E2E
+
+Przenośna zaszyfrowana pamięć aplikacji — przenieś profil na inne urządzenie
+
+Tryb incognito —
+unikalny dla SimpleX Chat
+
+## Co sprawia, że SimpleX jest prywatny
+
+### Tymczasowe anonimowe identyfikatory parami
+
+SimpleX używa tymczasowych anonimowych adresów par i poświadczeń dla każdego kontaktu użytkownika lub członka grupy.
+
+Pozwala na dostarczanie wiadomości bez identyfikatorów profilu użytkownika, zapewniając lepszą prywatność metadanych niż rozwiązania alternatywne.
+
+### Wymiana kluczy out-of-band
+
+Wiele sieci komunikacyjnych jest podatnych na ataki MITM ze strony serwerów lub dostawców sieci.
+
+Aby temu zapobiec aplikacje SimpleX przekazują klucze jednorazowe out-of-band, gdy udostępniasz adres jako link lub kod QR.
+
+### Dwie warstwy szyfrowania typu end-to-end
+
+Protokół double-ratchet —
+OTR messaging z perfect forward secrecy i break-in recovery.
+
+NaCL cryptobox w każdej kolejce, aby zapobiec korelacji ruchu między kolejkami wiadomości, jeśli bezpieczeństwo protokołu TLS zostanie naruszone.
+
+### Weryfikacja integralności wiadomości
+
+Aby zagwarantować integralność, wiadomości są kolejno numerowane i zawierają hash poprzedniej wiadomości.
+
+Jeśli jakaś wiadomość zostanie dodana, usunięta lub zmieniona, odbiorca zostanie o tym powiadomiony.
+
+### Dodatkowa warstwa szyfrowania serwera
+
+Dodatkowa warstwa szyfrowania serwera w celu dostarczenia do odbiorcy, aby zapobiec korelacji między odebranym i wysłanym ruchem serwera, jeśli bezpieczeństwo protokołu TLS zostanie naruszone.
+
+### Mieszanie wiadomości w celu zmniejszenia korelacji
+
+Serwery SimpleX działają jak węzły mieszania o niskim opóźnieniu — wiadomości przychodzące i wychodzące mają inną kolejność.
+
+### Bezpieczny uwierzytelniony transport TLS
+
+Do połączeń klient-serwer używany jest tylko TLS 1.2/1.3 z silnymi algorytmami.
+
+Odcisk palca serwera i wiązanie kanałów zapobiegają atakom MITM i replay.
+
+Wznowienie połączenia jest wyłączone, aby zapobiec atakom na sesje.
+
+### Możliwy dostęp za pośrednictwem sieci Tor
+
+Aby chronić swój adres IP, możesz uzyskać dostęp do serwerów przez Tor lub inną sieć nakładki transportowej.
+
+Aby użyć SimpleX przez Tor zainstaluj [aplikację Orbot na android](https://guardianproject.info/apps/org.torproject.android/) i włącz proxy SOCKS5 (lub VPN [na iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Jednokierunkowe kolejki wiadomości
+
+Każda kolejka z wiadomościami przekazuje wiadomości w jednym kierunku, z różnymi adresami wysyłania i odbierania.
+
+Zmniejsza wektory ataku, w porównaniu do tradycyjnych brokerów wiadomości, oraz dostępne metadane.
+
+### Wielowarstwowy padding treści
+
+SimpleX używa paddingu treści dla każdej warstwy szyfrowania, aby udaremnić ataki na rozmiar wiadomości.
+
+Dzięki temu wiadomości o różnych rozmiarach wyglądają tak samo dla serwerów i obserwatorów sieci.
+
+## Sieć SimpleX
+
+SimpleX Chat zapewnia najlepszą prywatność dzięki połączeniu zalet sieci P2P i sieci federacyjnych.
+
+### W przeciwieństwie do sieci P2P
+
+Wszystkie wiadomości są wysyłane przez serwery, co zapewnia lepszą prywatność metadanych i niezawodne asynchroniczne dostarczanie wiadomości, przy jednoczesnym unikaniu wielu .
+
+# Porównanie z protokołami komunikacyjnymi P2P
+
+Protokoły [P2P](https://en.wikipedia.org/wiki/Peer-to-peer) i aplikacje do przesyłania wiadomości mają różne problemy, które czynią je mniej niezawodnymi niż SimpleX, bardziej skomplikowanymi w analizie i podatnymi na kilka rodzajów ataków.
+
+1. Sieci P2P opierają się na pewnym wariancie [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) do przekazywania wiadomości. DHT muszą równoważyć gwarancję dostarczenia i opóźnienie. SimpleX ma zarówno lepszą gwarancję dostarczenia, jak i mniejsze opóźnienia niż P2P, ponieważ wiadomość może być nadmiarowo przepuszczona przez kilka serwerów równolegle, z wykorzystaniem serwerów wybranych przez odbiorcę. W sieciach P2P wiadomość jest przepuszczana przez , *O(log N)* węzłów sekwencyjnie, z wykorzystaniem węzłów wybranych przez algorytm.
+2. Projekt SimpleX, w przeciwieństwie do większości sieci P2P, nie posiada żadnych globalnych identyfikatorów użytkowników, nawet tymczasowych, a jedynie używa tymczasowych identyfikatorów parami, zapewniając lepszą anonimowość i ochronę metadanych.
+3. P2P nie rozwiązuje [ataku MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problemu, a większość istniejących implementacji nie używa wiadomości out-of-band do początkowej wymiany klucza. SimpleX używa wiadomości out-of-band lub, w niektórych przypadkach, wcześniej istniejących bezpiecznych i zaufanych połączeń do początkowej wymiany klucza.
+4. Implementacje P2P mogą być blokowane przez niektórych dostawców Internetu (np. [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX jest agnostykiem transportowym — może działać przez standardowe protokoły internetowe, np. WebSockets.
+5. Wszystkie znane sieci P2P mogą być podatne na [atak Sybil](https://en.wikipedia.org/wiki/Sybil_attack), ponieważ każdy węzeł jest możliwy do odkrycia, a sieć działa jako całość. Znane środki łagodzące wymagają albo scentralizowanego komponentu, albo kosztownego [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX nie ma możliwości odkrywania serwerów, jest pofragmentowana i działa jako wiele odizolowanych podsieci, co uniemożliwia ataki na całą sieć.
+6. Sieci P2P mogą być podatne na atak [DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), kiedy klienci mogą rozgłaszać i wzmacniać ruch, co powoduje odmowę usługi w całej sieci. Klienci SimpleX przekazują jedynie ruch ze znanego połączenia i nie mogą być wykorzystani przez atakującego do wzmocnienia ruchu w całej sieci.
+
+---
+
+### W przeciwieństwie do sieci federacyjnych
+
+Serwery przekaźnikowe SimpleX NIE przechowują profili użytkowników, kontaktów i dostarczonych wiadomości, NIE łączą się ze sobą i NIE ma katalogu serwerów.
+
+---
+
+### Sieć SimpleX
+
+serwery zapewniają jednokierunkowe kolejki do łączenia użytkowników, ale nie mają wglądu w graf połączeń sieciowych — robią to tylko użytkownicy.
+
+## Objaśnienie SimpleX
+
+1. Jakie są doświadczenia użytkowników
+
+2. Jak to działa
+
+3. Co widzą serwery
+
+1. Jakie są doświadczenia użytkowników
+
+Możesz tworzyć kontakty i grupy oraz prowadzić dwukierunkowe rozmowy, jak w każdym innym komunikatorze.
+
+Jak może to działać z jednokierunkowymi kolejkami i bez identyfikatorów profili użytkowników?
+
+2. Jak to działa
+
+Dla każdego połączenia używasz dwóch oddzielnych kolejek z wiadomościami do wysyłania i odbierania wiadomości przez różne serwery.
+
+Serwery przekazują wiadomości tylko w jedną stronę, nie mając pełnego obrazu konwersacji ani połączeń użytkownika.
+
+3. Co widzą serwery
+
+Serwery mają osobne anonimowe poświadczenia dla każdej kolejki i nie wiedzą do jakich użytkowników one należą.
+
+Użytkownicy mogą jeszcze bardziej zwiększyć prywatność metadanych, używając Tor do uzyskania dostępu do serwerów, co zapobiega korelacji na podstawie adresu IP.
+
+## Porównanie z innymi protokołami
+
+|  |  | Signal, duże platformy | XMPP, Matrix | Protokoły sieci P2P |
+| --- | --- | --- | --- | --- |
+| Wymaga globalnej tożsamości | Nie - prywatne | Tak [1] | Tak [2] | Tak [3] |
+| Możliwość ataku MITM | Nie - bezpieczny [4] | Tak [5] | Tak | Tak |
+| Zależność od DNS | Nie - odporny | Tak | Tak | Nie |
+| Sieć pojedyncza lub scentralizowana | Nie - zdecentralizowany | Tak | Nie - sfederowany [6] | Tak [7] |
+| Centralny komponent lub inny atak w całej sieci | Nie - odporny | Tak | Tak [2] | Tak [8] |
+
+---
+
+1. Zazwyczaj na podstawie numeru telefonu, w niektórych przypadkach na podstawie nazwy użytkownika
+2. Adresy oparte na DNS
+3. Klucz publiczny lub inny globalnie unikalny identyfikator (ID)
+4. Przekaźniki SimpleX nie mogą skompromitować szyfrowania e2e. Zweryfikuj kody bezpieczeństwa aby złagodzić atak na kanał pozapasmowy
+5. Jeśli bezpieczeństwo serwerów operatora zostało naruszone. Zweryfikuj kody bezpieczeństwa w Signalu lub innej aplikacji aby to złagodzić
+6. Nie chroni prywatności metadanych użytkowników
+7. Podczas gdy sieci P2P są rozproszone, nie są sfederowane — działają jako jedna sieć
+8. Sieci P2P albo mają centralny organ, albo cała sieć może zostać skompromitowana — [zobacz tutaj](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Porównanie zabezpieczeń szyfrowania end-to-end w różnych komunikatorach
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Wypełnianie wiadomości | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Wyrzeczenie (wiarygodne zaprzeczenie) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Poufność przekazywania informacji | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Bezpieczeństwo po naruszeniu zabezpieczeń | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Wymiana kluczy 2-składnikowych | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Hybrydowe szyfrowanie postkwantowe | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar wypełnia wiadomości do zaokrąglonego rozmiaru do maksymalnie 1024 bajtów, Signal - do 160 bajtów
+2. Repudiatacja (wiarygodne zaprzeczenie) nie obejmuje połączenia klient-serwer.
+3. Wydaje się, że użycie podpisów kryptograficznych zagraża repudiatacji (wiarygodnemu zaprzeczeniu), ale należy je wyjaśnić.
+4. Wdrożenie wielu urządzeń zagraża zabezpieczeniu po naruszeniu bezpieczeństwa systemu Double Ratchet — [zobacz tutaj](https://eprint.iacr.org/2021/626.pdf).
+5. Wymiana kluczy 2-składnikowych jest opcjonalna poprzez weryfikację kodu bezpieczeństwa.
+6. Post-kwantowe, kluczowe porozumienie jest "rzadkie" — chroni tylko niektóre kroki systemu Ratchet.
diff --git a/pl/messaging/index.html b/pl/messaging/index.html
index fa3140d574..0671b0d54f 100644
--- a/pl/messaging/index.html
+++ b/pl/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Masz pełną prywatność</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jesteś chroniony<br>przed spamem i nadużyciami</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Masz kontrolę nad swoimi danymi</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jesteś właścicielem sieci SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Pozwala na dostarczanie wiadomości bez identyfikatorów profilu użytkownika, zapewniając lepszą prywatność metadanych niż rozwiązania alternatywne.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
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@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Aby temu zapobiec aplikacje SimpleX przekazują klucze jednorazowe out-of-band, gdy udostępniasz adres jako link lub kod QR.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
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@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox w każdej kolejce, aby zapobiec korelacji ruchu między kolejkami wiadomości, jeśli bezpieczeństwo protokołu TLS zostanie naruszone.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Jeśli jakaś wiadomość zostanie dodana, usunięta lub zmieniona, odbiorca zostanie o tym powiadomiony.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
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@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Dodatkowa warstwa szyfrowania serwera w celu dostarczenia do odbiorcy, aby zapobiec korelacji między odebranym i wysłanym ruchem serwera, jeśli bezpieczeństwo protokołu TLS zostanie naruszone.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
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@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Serwery SimpleX działają jak węzły mieszania o niskim opóźnieniu — wiadomości przychodzące i wychodzące mają inną kolejność.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Wznowienie połączenia jest wyłączone, aby zapobiec atakom na sesje.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Aby użyć SimpleX przez Tor zainstaluj <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">aplikację Orbot na android</a> i włącz proxy SOCKS5 (lub VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">na iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Zmniejsza wektory ataku, w porównaniu do tradycyjnych brokerów wiadomości, oraz dostępne metadane.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
                     </div>
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@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Dzięki temu wiadomości o różnych rozmiarach wyglądają tak samo dla serwerów i obserwatorów sieci.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Stuknij, aby zamknąć</p>
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@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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diff --git a/pl/old/index.html b/pl/old/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Masz pełną prywatność</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jesteś chroniony<br>przed spamem i nadużyciami</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Masz kontrolę nad swoimi danymi</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Jesteś właścicielem sieci SimpleX</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pl/why.md b/pl/why.md
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+# Urodziłeś się bez konta.
+
+Nikt nie śledził twoich rozmów. Nikt nie rysował mapy miejsc, w których byłeś. Prywatność nigdy nie była funkcją — była sposobem na życie.
+
+Następnie przenieśliśmy się do sieci, a każda platforma prosiła o podanie danych osobowych — imienia i nazwiska, numeru telefonu, znajomych. Zaakceptowaliśmy fakt, że ceną za możliwość komunikowania się z innymi jest ujawnienie komuś, z kim rozmawiamy. Tak było w przypadku każdego pokolenia, ludzi i technologii — telefonu, poczty elektronicznej, komunikatorów, mediów społecznościowych. Wydawało się to jedyną możliwą opcją.
+
+Jest jeszcze inny sposób. Sieć bez numerów telefonów. Bez nazw użytkowników. Bez kont. Bez jakichkolwiek tożsamości użytkowników. Sieć, która łączy ludzi i przesyła zaszyfrowane wiadomości, nie wiedząc, kto jest podłączony.
+
+Nie chodzi o lepszy zamek w drzwiach kogoś innego. Nie chodzi o milszego właściciela, który szanuje twoją prywatność, ale nadal prowadzi rejestr wszystkich odwiedzających. Nie jesteś gościem. Jesteś w domu. Żaden król nie może do niego wejść — jesteś suwerenem.
+
+Twoje rozmowy należą do Ciebie, tak jak zawsze było przed pojawieniem się Internetu. Sieć nie jest miejscem, które odwiedzasz. Jest miejscem, które tworzysz i które należy do Ciebie. Nikt nie może Ci tego odebrać, niezależnie od tego, czy jest to miejsce prywatne, czy publiczne.
+
+Najstarsza ludzka wolność — możliwość rozmowy z inną osobą bez bycia obserwowanym — opiera się na infrastrukturze, która nie może jej zdradzić.
+
+Ponieważ zniszczyliśmy moc pozwalającą poznać, kim jesteś. Więc *twoja* moc nigdy nie będzie Ci odebrana.
+
+Ciesz się swobodą w swojej sieci.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/pl/why/index.html b/pl/why/index.html
index ce87701ea9..f3d5c316c1 100644
--- a/pl/why/index.html
+++ b/pl/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pl/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Ciesz się swobodą w swojej sieci.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/privacy.md b/privacy.md
new file mode 100644
index 0000000000..79652a9df0
--- /dev/null
+++ b/privacy.md
@@ -0,0 +1,255 @@
+# SimpleX Chat Operators Privacy Policy and Conditions of Use
+
+## Summary
+
+[Introduction](#introduction) and [General principles](#general-principles) cover SimpleX Chat network design, the network operators, and the principles of privacy and security provided by SimpleX network.
+
+[Privacy policy](#privacy-policy) covers:
+- data stored only on your device - [your profiles](#user-profiles), delivered [messages and files](#messages-and-files). You can transfer this information to another device, and you are responsible for its preservation - if you delete the app it will be lost.
+- [private message delivery](#private-message-delivery) that protects your IP address and connection graph from the destination servers.
+- [undelivered messages and files](#storage-of-messages-and-files-on-the-servers) stored on the servers.
+- [how users connect](#connections-with-other-users) without any user profile identifiers.
+- [iOS push notifications](#ios-push-notifications) privacy limitations.
+- [user support](#user-support), [SimpleX directory](#simplex-directory) and [any other data](#another-information-stored-on-the-servers) that may be stored on the servers.
+- [preset server operators](#preset-server-operators) and the [information they may share](#information-preset-server-operators-may-share).
+- [source code license](#source-code-license) and [updates to this document](#updates).
+
+[Conditions of Use](#conditions-of-use-of-software-and-infrastructure) are the conditions you need to accept to use SimpleX Chat applications and the relay servers of preset operators. Their purpose is to protect the users and preset server operators.
+
+*Please note*: this summary and any links in this document are provided for information only - they are not a part of the Privacy Policy and Conditions of Use.
+
+## Introduction
+
+SimpleX Chat (also referred to as SimpleX) is the first communication network based on a new protocol stack that builds on the same ideas of complete openness and decentralization as email and web, with the focus on providing security and privacy of communications, and without compromising on usability.
+
+SimpleX messaging protocol is the first protocol that has no user profile IDs of any kind, not even random numbers, cryptographic keys or hashes that identify the users. SimpleX apps allow their users to send messages and files via relay server infrastructure. Relay server owners and operators do not have any access to your messages, thanks to quantum-resistant double-ratchet end-to-end encryption algorithm (also known as Signal algorithm - do not confuse with Signal protocols or platform) and additional encryption layers, and they also have no access to your profile and contacts - as they do not host user accounts.
+
+Double ratchet algorithm has such important properties as [forward secrecy](https://simplex.chat/docs/glossary.md#forward-secrecy), sender [repudiation](https://simplex.chat/docs/glossary.md#) and break-in recovery (also known as [post-compromise security](https://simplex.chat/docs/glossary.md#post-compromise-security)).
+
+If you believe that any part of this document is not aligned with SimpleX network mission or values, please raise it via [email](mailto:chat@simplex.chat) or [chat](https://smp6.simplex.im/a#lrdvu2d8A1GumSmoKb2krQmtKhWXq-tyGpHuM7aMwsw).
+
+## Privacy Policy
+
+### General principles
+
+SimpleX network software uses established industry practices for security and encryption to provide secure [end-to-end encrypted](https://simplex.chat/docs/glossary.md#end-to-end-encryption) messaging via private connections. This encryption is protected from [man-in-the-middle attack](https://simplex.chat/docs/glossary.md#man-in-the-middle-attack) by the relay servers, even if they are modified or compromised.
+
+SimpleX software is built on top of SimpleX messaging and application protocols, based on a new message routing protocol allowing to establish private connections without having identifiers assigned to its users - it does not use emails, phone numbers, usernames, identity keys or any other user profile identifiers to pass messages between the user applications.
+
+SimpleX software is similar in its design approach to email clients and browsers - it allows you to have full control of your data and freely choose the relay server operators, in the same way you choose which website or email provider to use, or use your own relay servers, simply by changing the configuration of the client software. The only current restriction to that is Apple push notifications - at the moment they can only be delivered via the servers operated by SimpleX Chat Ltd, as explained below. We are exploring the solutions to deliver push notifications to iOS devices via other providers or users' own servers.
+
+SimpleX network operators are not communication service provider, and provide public relays "as is", as experimental, without any guarantees of availability or data retention. The operators of the relay servers preset in the app ("Preset Server Operators"), including SimpleX Chat Ltd, are committed to maintain a high level of availability, reliability and security. SimpleX client apps can have multiple preset relay server operators that you can opt-in or opt-out of using. You are and will continue to be able to use any other operators or your own servers.
+
+SimpleX network design is based on the principles of user and data sovereignty, and device and operator portability.
+
+The implementation security assessment of SimpleX cryptography and networking was done in October 2022 by [Trail of Bits](https://www.trailofbits.com/about), and most fixes were released in v4.2 – see [the announcement](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+The cryptographic review of SimpleX protocols design was done in July 2024 by Trail of Bits – see [the announcement](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md).
+
+### Your information
+
+#### User profiles
+
+Servers used by SimpleX Chat apps do not create, store or identify user chat profiles. The profiles you can create in the app are local to your device, and can be removed at any time via the app.
+
+When you create the local profile, no records are created on any of the relay servers, and infrastructure operators, whether preset in the app or any other, have no access to any part of your information, and even to the fact that you created a profile - it is a local record stored only on your device. That means that if you delete the app, and have no backup, you will permanently lose all your data and the private connections you created with other software users.
+
+You can transfer the profile to another device by creating a backup of the app data and restoring it on the new device, but you cannot use more than one device with the copy of the same profile at the same time - it will disrupt any active conversations on either or both devices, as a security property of end-to-end encryption.
+
+#### Messages and Files
+
+SimpleX relay servers cannot decrypt or otherwise access the content or even the size of your messages and files you send or receive. Each message is padded to a fixed size of 16kb. Each file is sent in chunks of 64kb, 256kb, 1mb or 4mb via all or some of the configured file relay servers. Both messages and files are sent end-to-end encrypted, and the servers do not have technical means to compromise this encryption, because part of the [key exchange](https://simplex.chat/docs/glossary.md#key-exchange) happens out-of-band.
+
+Your message history is stored only on your own device and the devices of your contacts. While the recipients' devices are offline, messaging relay servers temporarily store end-to-end encrypted messages – you can configure which relay servers are used to receive the messages from the new contacts, and you can manually change them for the existing contacts too.
+
+#### Private message delivery 
+
+You do not have control over which servers are used to receive messages by your contacts - these servers are chosen by your contacts. To send messages your client by default uses configured servers to forward messages to the destination servers, thus protecting your IP address from the servers chosen by your contacts.
+
+In case you use preset servers of more than one operator, the app will prefer to use a server of an operator different from the operator of the destination server to forward messages, preventing destination server to correlate messages as belonging to one client.
+
+Preset servers do not log IP addresses of the user devices that connect to them.
+
+You can additionally use VPN or some overlay network (e.g., Tor) to hide your IP address from the servers chosen by you.
+
+*Please note*: the clients allow changing configuration to connect to the destination servers directly. It is not recommended - if you make such change, your IP address will be visible to the destination servers.
+
+#### Storage of messages and files on the servers
+
+The messages stored on the servers are end-to-end encrypted, and cannot be read by server owners.
+
+The messages are irreversibly removed from the preset relay servers as soon as they are delivered or after 21 days.
+
+Other relay servers may use message logs that would result in longer storage of delivered messages, until the log file is rotated, which normally should happen within one month if servers use the same code as preset servers.
+
+The files are stored on file relay servers for the time configured in the relay servers you use (48 hours for preset file servers).
+
+#### Connections with other users
+
+When you create a connection with another user, two messaging queues (you can think about them as mailboxes) are created on messaging relay servers (chosen by you and your contact each), that can be the preset servers or the servers that you and your contact configured in the app. SimpleX messaging protocol uses separate queues for direct and response messages, and the apps prefer to create these queues on two different relay servers, or, if available, the relays of two different operators, for increased privacy, in case you have more than one relay server configured in the app, which is the default.
+
+Preset and unmodified SimpleX relay servers do not store information about which queues are linked to your profile on the device, and they do not collect any information that would allow infrastructure owners and operators to establish that these queues are related to your device or your profile - the access to each queue is authorized by two anonymous unique cryptographic keys, different for each queue, and separate for sender and recipient of the messages.
+
+#### Connection links privacy
+
+When you create a connection with another user, the app generates a one-time link/QR code that can be shared with the user to establish the connection via any channel (email, any other messenger, or a video call). This link is safe to share via insecure channels, as long as you can identify the recipient and also trust that this channel did not replace this link (to mitigate the latter risk you can validate the security code via the app).
+
+The connection link contains the address of the server used to establish the connection. Your profile name and picture are stored on this server in encrypted form until your contact uses the link, after which this data is removed. The server cannot access this data without the link.
+
+The old connection "links" contained SimpleX Chat Ltd domain name `simplex.chat`, but this site is never accessed by the app - you could replace the initial part of the old link `https://simplex.chat/` either with `simplex:/` or with any other domain name.
+
+#### iOS Push Notifications
+
+This section applies only to the notification servers operated by SimpleX Chat Ltd.
+
+When you choose to use instant push notifications in SimpleX iOS app, because the design of push notifications requires storing the device token on notification server, the notifications server can observe how many messaging queues your device has notifications enabled for, and approximately how many messages are sent to each queue.
+
+Preset notification server cannot observe the actual addresses of these queues, as a separate address is used to subscribe to the notifications. It also cannot observe who sends messages to you. Apple push notifications servers can only observe how many notifications are sent to you, but not from how many contacts, or from which messaging relays, as notifications are delivered to your device end-to-end encrypted by one of the preset notification servers - these notifications only contain end-to-end encrypted metadata, not even encrypted message content, and they look completely random to Apple push notification servers.
+
+You can read more about the design of iOS push notifications [here](https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.md#our-ios-approach-has-one-trade-off).
+
+#### Another information stored on the servers
+
+Additional technical information can be stored on the network servers, including randomly generated authentication tokens, keys, push tokens, and other material that is necessary to transmit messages. SimpleX network design limits this additional technical information to the minimum required to operate the software and servers. To prevent server overloading or attacks, the servers can temporarily store data that can link to particular users or devices, including IP addresses, geographic location, or information related to the transport sessions. This information is not stored for the absolute majority of the app users, even for those who use the servers very actively.
+
+Because SimpleX servers do not create user accounts and do not store any identifiers linking transport data to message queues or user profiles, this technical data cannot be used by server operators to identify any person.
+
+#### SimpleX Directory
+
+This section applies only to the experimental group directory chat bot operated by SimpleX Chat Ltd.
+
+[SimpleX Directory](https://simplex.chat/docs/directory.md) bot stores: your search requests, the messages and the members profiles in the registered groups. You can connect to SimpleX Directory via [this address](https://smp4.simplex.im/a#lXUjJW5vHYQzoLYgmi8GbxkGP41_kjefFvBrdwg-0Ok).
+
+You can also view the groups registered in SimpleX directory via the browser at [simplex.chat/directory](https://simplex.chat/directory)
+
+#### Public groups and content channels
+
+You may participate in a public group and receive content from a public channel (Group). In case you send messages or comments to the Group, you grant a license:
+- to all recipients:
+  - to share your messages with the new Group members and outside of the group, e.g. via quoting (replying), forwarding and copy-pasting your message. When your message is deleted or marked as deleted, the copies of your message will not be deleted.
+  - to retain a copy of your messages according to the Group settings (e.g., the Group may allow irreversible message deletion from the recipient devices for a limited period of time, or it may only allow to edit and mark messages as deleted on recipient devices). Deleting message from the recipient devices or marking message as deleted revokes the license to share the message.
+- to Group owners: to share your messages with the new Group members as history of the Group. Currently, the Group history shared with the new members is limited to 100 messages.
+
+#### Public channels and chat relays (beta)
+
+Public channels are experimental - their functionality and privacy properties may change.
+
+Channel owners use chat relays that retain messages to deliver them to channel subscribers. The chat relays may be operated by the channel owners, by preset operators or by 3rd parties. The chat relays are client applications on SimpleX network - they cannot identify subscribers. Neither you nor channel owners grant any content license to chat relay operators.
+
+#### Public contact, group and channel addresses
+
+Public addresses contain profile name, picture and other profile details. This data is encrypted on the servers, and can only be accessed via the address. Server operators cannot list addresses and cannot access this data without having the address. Public address data remains on the servers until removed by the user via the app. If you lose access to the app without a backup, server operators have no way to verify address ownership and can only remove addresses following due process.
+
+#### User Support
+
+The app includes support contact operated by SimpleX Chat Ltd. If you contact support, any personal data you share is kept only for the purposes of researching the issue and contacting you about your case. We recommend contacting support [via chat](https://smp6.simplex.im/a#lrdvu2d8A1GumSmoKb2krQmtKhWXq-tyGpHuM7aMwsw) when it is possible, and avoid sharing any personal information.
+
+### Preset Server Operators
+
+Preset server operators will not share the information or any metadata on their servers with each other, other than aggregate usage statistics.
+
+Preset server operators must not provide general access to their servers or the data on their servers to each other.
+
+Preset server operators will provide non-administrative access to control port of preset servers to SimpleX Chat Ltd, for the purposes of removing illegal content identified in publicly accessible resources (contact and group addresses, and downloadable files). This control port access only allows deleting known links and files, and accessing aggregate server-wide statistics, but does NOT allow enumerating any information on the servers or accessing statistics related to specific users.
+
+### Information Preset Server Operators May Share
+
+The preset server operators use third parties. While they do not have access and cannot share any user data, these third parties may access the encrypted user messages (but NOT the actual unencrypted message content or size) as it is stored or transmitted via the servers. Hosting and network providers can also store IP addresses and other transport information as part of their logs.
+
+SimpleX Chat Ltd uses a third party for email services - if you ask for support via email, your and SimpleX Chat Ltd email providers may access these emails according to their privacy policies and terms. When the request is sensitive, please contact us via SimpleX Chat apps or using encrypted email using PGP key published at [openpgp.org](https://keys.openpgp.org/vks/v1/by-fingerprint/FB44AF81A45BDE327319797C85107E357D4A17FC).
+
+The cases when the preset server operators may share the data temporarily stored on the servers:
+
+- To meet any applicable law, or enforceable governmental request or court order.
+- To enforce applicable terms, including investigation of potential violations.
+- To detect, prevent, or otherwise address fraud, security, or technical issues.
+- To protect against harm to the rights, property, or safety of software users, operators of preset servers, or the public as required or permitted by law.
+
+Reports on requests for user data are published in [Transparency reports](https://simplex.chat/transparency/index.html). To date, no user information was provided in response to any requests. If the preset server operators are ever required to provide information, they will follow the due legal process to limit any information shared to the minimally required by law.
+
+### Source code license
+
+As this software is fully open-source and provided under AGPLv3 license, all infrastructure owners and operators, and the developers of the client and server applications who use the SimpleX Chat source code, are required to publish any changes to this software under the same AGPLv3 license - including any modifications to the servers.
+
+In addition to the AGPLv3 license terms, the preset relay server operators are committed to the software users that these servers will always be compiled from the [published open-source code](https://github.com/simplex-chat/simplexmq), without any modifications.
+
+Users can independently [reproduce builds](https://simplex.chat/reproduce/index.html) to verify that the published client and server binaries were compiled from the published code.
+
+### Updates
+
+This Privacy Policy applies to SimpleX Chat Ltd and all other preset server operators you use in the app.
+
+This Privacy Policy may be updated as needed so that it is current, accurate, and as clear as possible. When it is updated, you will have to review and accept the changed policy within 30 days of such changes to continue using preset relay servers. Even if you fail to accept the changed policy, your continued use of SimpleX Chat software applications and preset relay servers confirms your acceptance of the updated Privacy Policy.
+
+Please also read The Conditions of Use of Software and Infrastructure below.
+
+If you have questions about this Privacy Policy or data protection please contact SimpleX Chat Ltd (company number 13691484, registered at 20-22 Wenlock Road, London, United Kingdom N1 7GU) via [email](mailto:chat@simplex.chat) or [chat](https://smp6.simplex.im/a#lrdvu2d8A1GumSmoKb2krQmtKhWXq-tyGpHuM7aMwsw).
+
+## Conditions of Use of Software and Infrastructure
+
+You accept the Conditions of Use of Software and Infrastructure ("Conditions") by installing or using any of SimpleX Chat software or using any of server infrastructure (collectively referred to as "Applications") operated by the Preset Server Operators, including SimpleX Chat Ltd, whether these servers are preset in the software or not.
+
+**Minimal age**. You must be at least 13 years old to use SimpleX Chat Applications. The minimum age to use SimpleX Applications without parental approval may be higher in your country.
+
+**Infrastructure**. Infrastructure of the preset server operators includes messaging and file relay servers. SimpleX Chat Ltd also provides iOS push notification servers for public use. This infrastructure does not have any modifications from the [published open-source code](https://github.com/simplex-chat/simplexmq) available under AGPLv3 license. Any infrastructure provider, whether commercial or not, is required by the Affero clause (named after Affero Inc. company that pioneered the community-based Q&A sites in early 2000s) to publish any modifications under the same license. The statements in relation to Infrastructure and relay servers anywhere in this document assume no modifications to the published code, even in the cases when it is not explicitly stated.
+
+**Client applications**. SimpleX Chat client application Software (referred to as "app" or "apps") also has no modifications compared with published open-source code, and any developers of the alternative client apps based on SimpleX Chat code are required to publish any modifications under the same AGPLv3 license. Client applications should not include any tracking or analytics code, and do not share any tracking information with SimpleX Chat Ltd, preset server operators or any other third parties. If you ever discover any tracking or analytics code, please report it to SimpleX Chat Ltd, so it can be removed.
+
+Client applications must not include any code that could compromise the security of end-to-end encryption of files and messages. Client applications must not send anything not directly required for users communications without explicit users' consent.
+
+**Accessing the infrastructure**. For the efficiency of the network access, the client Software by default accesses all queues your app creates on any relay server within one user profile via the same network (TCP/IP) connection. At the cost of additional traffic this configuration can be changed to use different transport session for each connection. Relay servers do not collect information about which queues were created or accessed via the same connection, so the relay servers cannot establish which queues belong to the same user profile. Whoever might observe your network traffic would know which relay servers you use, and how much data you send, but not to whom it is sent - the data that leaves the servers is always different from the data they receive - there are no identifiers or ciphertext in common, even inside TLS encryption layer. Please refer to the [technical design document](https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md) for more information about the privacy model and known security and privacy risks.
+
+**Privacy of user data**. Servers do not retain any data you transmit for any longer than necessary to deliver the messages between apps. Preset server operators collect aggregate statistics across all their servers, as supported by published code and can be enabled by any infrastructure operator, but not any statistics per-user, or per geographic location, or per IP address, or per transport session. SimpleX Chat Ltd does not have information about how many people use SimpleX Chat applications, it only knows an approximate number of app installations and the aggregate traffic through the preset servers. In any case, preset server operators do not and will not sell or in any way monetize user data. The future business model assumes charging for some optional Software features instead, in a transparent and fair way.
+
+**Operating Infrastructure**. For the purpose of using SimpleX Chat Software, if you continue using preset servers, you agree that your end-to-end encrypted messages are transferred via the preset servers in any countries where preset server operators have or use facilities and service providers or partners. The information about geographic location and hosting providers of the preset messaging servers is available on server pages.
+
+**Software**. You agree to downloading and installing updates to SimpleX Chat Applications when they are available; they would only be automatic if you configure your devices in this way.
+
+**Traffic and device costs**. You are solely responsible for the traffic and device costs that you incur while using SimpleX Chat Applications, and any associated taxes.
+
+**Legal usage**. You agree to use SimpleX Chat Applications only for legal purposes. You will not use (or assist others in using) the Applications in ways that: 1) violate or infringe the rights of Software users, SimpleX Chat Ltd, other preset server operators, or others, including privacy, publicity, intellectual property, or other proprietary rights; 2) involve sending illegal communications, e.g. spam. While server operators cannot access content or identify messages or groups, in some cases the links to the illegal communications can be shared publicly on social media or websites. Preset server operators reserve the right to remove such links from the preset servers and disrupt the conversations that send illegal content via their servers, whether they were reported by the users or discovered by the operators themselves.
+
+**Damage to SimpleX Chat Ltd and Preset Server Operators**. You must not (or assist others to) access, use, modify, distribute, transfer, or exploit SimpleX Chat Applications in unauthorized manners, or in ways that harm Software users, SimpleX Chat Ltd, other preset server operators, their Infrastructure, or any other systems. For example, you must not 1) access preset operators' Infrastructure or systems without authorization, in any way other than by using the Software or by using a 3rd party client applications that satisfies the requirements of the Conditions of use (see the next section); 2) disrupt the integrity or performance of preset operators' Infrastructure; 3) collect information about the users in any manner; or 4) sell, rent, or charge for preset operators' Infrastructure. This does not prohibit you from providing your own Infrastructure to others, whether free or for a fee, as long as you do not violate these Conditions and AGPLv3 license, including the requirement to publish any modifications of the relay server software.
+
+**3rd party client applications**. You may use a 3rd party application (App) to access preset operators' Infrastructure or systems, provided that this App:
+- is compatible with the protocol specifications not older than 1 year,
+- provides user-to-user messaging only or enables automated chat bots sending messages requested by users (in case of bots, it must be made clear to the users that these are automated bots),
+- implements the same limits, rules and restrictions as Software,
+- requires that the users accept the same Conditions of use of preset operators' Infrastructure as in Software prior to providing access to this Infrastructure,
+- displays the notice that it is the App for using SimpleX network,
+- provides its source code under open-source license accessible to the users via the App interface. In case the App uses the source code of Software, the App's source code must be provided under AGPLv3 license, and in case it is developed without using Software code its source code must be provided under any widely recognized free open-source license,
+- does NOT use the branding of SimpleX Chat Ltd without the permission,
+- does NOT pretend to be Software,
+- complies with these Conditions of use.
+
+**Keeping your data secure**. SimpleX Chat is the first communication software that aims to be 100% private by design - server software neither has the ability to access your messages, nor it has information about who you communicate with. That means that you are solely responsible for keeping your device, your user profile and any data safe and secure. If you lose your phone or remove the Software from the device, you will not be able to recover the lost data, unless you made a back up. To protect the data you need to make regular backups, as using old backups may disrupt your communication with some of the contacts. SimpleX Chat Ltd and other preset server operators are not responsible for any data loss.
+
+**Storing the messages on the device**. The messages are stored in the encrypted database on your device. Whether and how database passphrase is stored is determined by the configuration of the Software you use. The databases created prior to 2023 or in CLI (terminal) app may remain unencrypted, and it will be indicated in the app interface. In this case, if you make a backup of the data and store it unencrypted, the backup provider may be able to access the messages. Please note, that the desktop apps can be configured to store the database passphrase in the configuration file in plaintext, and unless you set the passphrase when first running the app, a random passphrase will be used and stored on the device. You can remove it from the device via the app settings.
+
+**Storing the files on the device**. The files currently sent and received in the apps by default (except CLI app) are stored on your device encrypted using unique keys, different for each file, that are stored in the database. Once the message that the file was attached to is removed, even if the copy of the encrypted file is retained, it should be impossible to recover the key allowing to decrypt the file. This local file encryption may affect app performance, and it can be disabled via the app settings. This change will only affect the new files. If you later re-enable the encryption, it will also affect only the new files. If you make a backup of the app data and store it unencrypted, the backup provider will be able to access any unencrypted files. In any case, irrespective of the storage setting, the files are always sent by all apps end-to-end encrypted.
+
+**No Access to Emergency Services**. SimpleX Chat Applications do not provide access to emergency service providers like the police, fire department, hospitals, or other public safety organizations. Make sure you can contact emergency service providers through a mobile, fixed-line telephone, or other service.
+
+**Third-party services**. SimpleX Chat Applications may allow you to access, use, or interact with the websites of SimpleX Chat Ltd, preset server operators or other third-party websites, apps, content, and other products and services. When you use third-party services, their terms and privacy policies govern your use of those services.
+
+**Your Rights**. You own the messages and the information you transmit through SimpleX Applications. Your recipients are able to retain the messages they receive from you; there is no technical ability to delete data from their devices. While there are various app features that allow deleting messages from the recipients' devices, such as _disappearing messages_ and _full message deletion_, their functioning on your recipients' devices cannot be guaranteed or enforced, as the device may be offline or have a modified version of the Software. At the same time, repudiation property of the end-to-end encryption algorithm allows you to plausibly deny having sent the message, like you can deny what you said in a private face-to-face conversation, as the recipient cannot provide any proof to the third parties, by design.
+
+**License**. SimpleX Chat Ltd grants you a limited, revocable, non-exclusive, and non-transferable license to use SimpleX Chat Applications in accordance with these Conditions. The source-code of Applications is available and can be used under [AGPL v3 license](https://github.com/simplex-chat/simplex-chat/blob/stable/LICENSE).
+
+**SimpleX Chat Ltd Rights**. SimpleX Chat Ltd (and, where applicable, preset server operators) owns all copyrights, trademarks, domains, logos, trade secrets, and other intellectual property rights associated with the Applications. You may not use SimpleX Chat Ltd copyrights, trademarks, domains, logos, and other intellectual property rights unless you have SimpleX Chat Ltd written permission, and unless under an open-source license distributed together with the source code. To report copyright, trademark, or other intellectual property infringement, please contact chat@simplex.chat.
+
+**Disclaimers**. YOU USE SIMPLEX APPLICATIONS AT YOUR OWN RISK AND SUBJECT TO THE FOLLOWING DISCLAIMERS. SIMPLEX CHAT LTD PROVIDES APPLICATIONS ON AN “AS IS” BASIS WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, NON-INFRINGEMENT, AND FREEDOM FROM COMPUTER VIRUS OR OTHER HARMFUL CODE. SIMPLEX CHAT LTD DOES NOT WARRANT THAT ANY INFORMATION PROVIDED BY THEM IS ACCURATE, COMPLETE, OR USEFUL, THAT THEIR APPLICATIONS WILL BE OPERATIONAL, ERROR-FREE, SECURE, OR SAFE, OR THAT THEIR APPLICATIONS WILL FUNCTION WITHOUT DISRUPTIONS, DELAYS, OR IMPERFECTIONS. SIMPLEX CHAT LTD AND OTHER PRESET OPERATORS DO NOT CONTROL, AND ARE NOT RESPONSIBLE FOR, CONTROLLING HOW OR WHEN THE USERS USE APPLICATIONS. SIMPLEX CHAT LTD AND OTHER PRESET OPERATORS ARE NOT RESPONSIBLE FOR THE ACTIONS OR INFORMATION (INCLUDING CONTENT) OF THEIR USERS OR OTHER THIRD PARTIES. YOU RELEASE SIMPLEX CHAT LTD, OTHER PRESET OPERATORS, AFFILIATES, DIRECTORS, OFFICERS, EMPLOYEES, PARTNERS, AND AGENTS ("SIMPLEX PARTIES") FROM ANY CLAIM, COMPLAINT, CAUSE OF ACTION, CONTROVERSY, OR DISPUTE (TOGETHER, "CLAIM") AND DAMAGES, KNOWN AND UNKNOWN, RELATING TO, ARISING OUT OF, OR IN ANY WAY CONNECTED WITH ANY SUCH CLAIM YOU HAVE AGAINST ANY THIRD PARTIES.
+
+**Limitation of liability**. THE SIMPLEX PARTIES WILL NOT BE LIABLE TO YOU FOR ANY LOST PROFITS OR CONSEQUENTIAL, SPECIAL, PUNITIVE, INDIRECT, OR INCIDENTAL DAMAGES RELATING TO, ARISING OUT OF, OR IN ANY WAY IN CONNECTION WITH OUR CONDITIONS, US, OR SIMPLEX APPLICATIONS, EVEN IF THE SIMPLEX PARTIES HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THE AGGREGATE LIABILITY OF THE SIMPLEX PARTIES RELATING TO, ARISING OUT OF, OR IN ANY WAY IN CONNECTION WITH THESE CONDITIONS, THE SIMPLEX PARTIES, OR THE APPLICATIONS WILL NOT EXCEED ONE DOLLAR ($1). THE FOREGOING DISCLAIMER OF CERTAIN DAMAGES AND LIMITATION OF LIABILITY WILL APPLY TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW. THE LAWS OF SOME JURISDICTIONS MAY NOT ALLOW THE EXCLUSION OR LIMITATION OF CERTAIN DAMAGES, SO SOME OR ALL OF THE EXCLUSIONS AND LIMITATIONS SET FORTH ABOVE MAY NOT APPLY TO YOU. NOTWITHSTANDING ANYTHING TO THE CONTRARY IN THE CONDITIONS, IN SUCH CASES, THE LIABILITY OF THE SIMPLEX PARTIES WILL BE LIMITED TO THE EXTENT PERMITTED BY APPLICABLE LAW.
+
+**Availability**. The Applications may be disrupted, including for maintenance, upgrades, or network or equipment failures. SimpleX Chat Ltd may discontinue some or all of their Applications, including certain features and the support for certain devices and platforms, at any time. Preset server operators may discontinue providing the servers, at any time.
+
+**Resolving disputes**. You agree to resolve any Claim you have with SimpleX Chat Ltd and/or preset server operators relating to or arising from these Conditions, them, or the Applications in the courts of England and Wales. You also agree to submit to the personal jurisdiction of such courts for the purpose of resolving all such disputes. The laws of England govern these Conditions, as well as any disputes, whether in court or arbitration, which might arise between SimpleX Chat Ltd (or preset server operators) and you, without regard to conflict of law provisions.
+
+**Changes to the conditions**. SimpleX Chat Ltd may update the Conditions from time to time. The updated conditions have to be accepted within 30 days. Even if you fail to accept updated conditions, your continued use of SimpleX Chat Applications confirms your acceptance of the updated Conditions and supersedes any prior Conditions. You will comply with all applicable export control and trade sanctions laws. These Conditions cover the entire agreement between you and SimpleX Chat Ltd, and any preset server operators where applicable, regarding SimpleX Chat Applications. If you do not agree with these Conditions, you should stop using the Applications.
+
+**Enforcing the conditions**. If SimpleX Chat Ltd or preset server operators fail to enforce any of these Conditions, that does not mean they waive the right to enforce them. If any provision of the Conditions is deemed unlawful, void, or unenforceable, that provision shall be deemed severable from the Conditions and shall not affect the enforceability of the remaining provisions. The Applications are not intended for distribution to or use in any country where such distribution or use would violate local law or would subject SimpleX Chat Ltd to any regulations in another country. SimpleX Chat Ltd reserve the right to limit the access to the Applications in any country. Preset operators reserve the right to limit access to their servers in any country. If you have specific questions about these Conditions, please contact SimpleX Chat Ltd at chat@simplex.chat.
+
+**Ending these conditions**. You may end these Conditions with SimpleX Chat Ltd and preset server operators at any time by deleting the Applications from your devices and discontinuing use of the Infrastructure of SimpleX Chat Ltd and preset server operators. The provisions related to Licenses, Disclaimers, Limitation of Liability, Resolving dispute, Availability, Changes to the conditions, Enforcing the conditions, and Ending these conditions will survive termination of your relationship with SimpleX Chat Ltd and/or preset server operators.
+
+Updated April 18, 2026
diff --git a/privacy/index.html b/privacy/index.html
index fc52cd3e2e..1c94a50804 100644
--- a/privacy/index.html
+++ b/privacy/index.html
@@ -59,6 +59,10 @@
     
     <meta name="twitter:card" content="summary" />
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico" />
+    
+<link rel="alternate" type="text/markdown" href="/privacy.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#F3FAFF">
     <link href="/css/tailwind.css" rel="stylesheet" />
     <link rel="stylesheet" href="/css/blog.css" />
diff --git a/pt_BR/contact.md b/pt_BR/contact.md
new file mode 100644
index 0000000000..a1d36d64f9
--- /dev/null
+++ b/pt_BR/contact.md
@@ -0,0 +1,66 @@
+# Você recebeu um endereço para se conectar no SimpleX Chat
+
+## Leia o QR code com o aplicativo SimpleX Chat em seu telefone ou tablet.
+
+As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página — eles estão contidos no fragmento de hash do URL do link.
+
+Ainda não baixou o SimpleX Chat?
+
+Use os links abaixo para baixar o aplicativo.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Escanear o QR code do aplicativo
+
+# Você recebeu um endereço para se conectar no SimpleX Chat
+
+Para estabelecer uma conexão:
+
+Instale o aplicativo SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid)
+
+1
+
+Conectar no aplicativo
+
+Abra o aplicativo Simplex
+
+2
+
+Toque no botão "conectar" no aplicativo
+
+3
+
+## Escaneie o QR code com o aplicativo SimpleX Chat
+
+As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página —
+eles estão contidos no fragmento de hash do URL do link.
+
+## Instalação do SimpleX chat para o terminal
+
+Use esse comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Veja o SimpleX Chat Repositório no GitHub para as instruções sobre como fazer download ou compilá-lo a partir do código-fonte.
+
+---
+
+## Se você já instalou o SimpleX Chat para o terminal
+
+Se você já instalou SimpleX Chat para terminal v1.0.0+, copie o comando abaixo e use-o no bate-papo:
+
+## Junte-se ao SimpleX
+
+Convidamos você a participar da conversa
+
+[Junte-se à comunidade no REDDIT](https://www.reddit.com/r/SimpleXChat/) [Junte-se a nós no GitHub](https://github.com/simplex-chat) [Doe aqui para nos ajudar](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Inscreva-se para receber nossas atualizações
+
+---
+
+Obtenha o SimpleX [aplicativo desktop](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid)
diff --git a/pt_BR/contact/index.html b/pt_BR/contact/index.html
index 31fbb9a9ad..a40a90f820 100644
--- a/pt_BR/contact/index.html
+++ b/pt_BR/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Você recebeu um endereço para se conectar no SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Leia o QR code com o aplicativo SimpleX Chat em seu telefone ou tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página — eles estão contidos no fragmento de hash do URL do link.
+                As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página &mdash; eles estão contidos no fragmento de hash do URL do link.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ainda não baixou o SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use os links abaixo para baixar o aplicativo.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instale o aplicativo SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Toque no botão <span class="text-active-blue">"conectar"</span> no aplicativo</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Toque no botão <span class='text-active-blue'>"conectar"</span> no aplicativo</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Escaneie o QR code com o aplicativo SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página —<br> eles estão contidos no fragmento de hash do URL do link.
+                            As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página &mdash;<br> eles estão contidos no fragmento de hash do URL do link.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalação do SimpleX chat para o terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositório no GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Se você já instalou o SimpleX Chat para o terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Inscreva-se para receber nossas atualizações</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Digite seu endereço de email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtenha o SimpleX <a href="/downloads">aplicativo desktop</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pt_BR/fdroid.md b/pt_BR/fdroid.md
new file mode 100644
index 0000000000..64a600a7d3
--- /dev/null
+++ b/pt_BR/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat pelo F-Droid
+
+### Repositório SimpleX Chat
+
+Versões estáveis e beta criadas pelos desenvolvedores
+
+Para adicioná-lo ao seu cliente F-Droid, escaneie o QR code ou use este URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Assinatura de impressão digital de chave (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Repositório F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Versões estáveis criadas por F-Droid.org
+
+Os lançamentos para este repositório são feitos 1 ou 2 dias depois.
+
+Os repositórios SimpleX Chat e F-Droid.org assinam compilações com chaves diferentes. Para mudar, [exporte](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) o banco de dados de bate-papo e reinstale o aplicativo.
diff --git a/pt_BR/fdroid/index.html b/pt_BR/fdroid/index.html
index 22c219b7eb..117fd54c4f 100644
--- a/pt_BR/fdroid/index.html
+++ b/pt_BR/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat pelo F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Versões estáveis e beta criadas pelos desenvolvedores</p>
-                        <p>Para adicioná-lo ao seu cliente F-Droid, <span class="hide-on-mobile">escaneie o QR code ou</span> use este URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Para adicioná-lo ao seu cliente F-Droid, <span class='hide-on-mobile'>escaneie o QR code ou</span> use este URL:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Assinatura de impressão digital de chave (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Repositório F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Versões estáveis criadas por F-Droid.org</p>
                 <p class="mb-2">Os lançamentos para este repositório são feitos 1 ou 2 dias depois.</p>
-                <p class="mb-2">Os repositórios SimpleX Chat e F-Droid.org assinam compilações com chaves diferentes. Para mudar, <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">exporte</a> o banco de dados de bate-papo e reinstale o aplicativo.</p>
+                <p class="mb-2">Os repositórios SimpleX Chat e F-Droid.org assinam compilações com chaves diferentes. Para mudar, <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>exporte</a> o banco de dados de bate-papo e reinstale o aplicativo.</p>
             </div>
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     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pt_BR/file.md b/pt_BR/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/pt_BR/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/pt_BR/file/index.html b/pt_BR/file/index.html
index 138cb0604a..beaae21ab2 100644
--- a/pt_BR/file/index.html
+++ b/pt_BR/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pt_BR/index.html b/pt_BR/index.html
index e43d22aa65..6226966c51 100644
--- a/pt_BR/index.html
+++ b/pt_BR/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/pt_BR/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/pt_BR/fdroid" title="Aplicativo SimpleX no F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS - versão beta no TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS - versão beta no TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Auditorias de Segurança" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Agora</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/pt_BR/index.md b/pt_BR/index.md
new file mode 100644
index 0000000000..7184566f69
--- /dev/null
+++ b/pt_BR/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Seja Livre
+
+## Na Sua Rede
+
+A primeira rede sem IDs de usuário.
+Seus contatos, grupos e canais pertencem a você.
+
+Invest in SimpleX Chat. [Saiba mais.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [Aplicativo SimpleX no F-Droid](https://simplex.chat/pt_BR/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Auditorias de Segurança](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Auditorias
+de Segurança
+
+[Recomendaçẽos de mensageiros do Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Recomendações de mensageria do Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Publicações da Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Análise por Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [Entrevista no podcast OptOut](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Ninguém Pode Ver Com Quem Você Conversa
+
+Nem mesmo os servidores – todas as mensagens parecem ruído aleatório.
+
+Dezenas de milhões de mensagens entregues de forma privada todos os dias.
+
+[Saiba mais sobre SimpleX Messaging](https://simplex.chat/pt_BR/messaging)
+
+## A Rede É Sua
+
+Cada contato e grupo está no seu dispositivo, não no banco de dados de um servidor.
+
+Nenhuma entidade controla a rede – qualquer pessoa pode operar servidores.
+
+[Why we are building it](https://simplex.chat/pt_BR/why)
+
+## Financiado Pelos Seus Usuários
+
+Para manter a independência, grandes canais e comunidades pagarão pelos seus servidores.
+
+E os usuários agora podem investir no SimpleX Chat — o crowdfunding está ativo!
+
+[Investir no SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Roteiro do SimpleX para uma Internet Livre
+
+2026
+
+: Escala para Grandes Comunidades
+
+Fugindo de plataformas centralizadas
+
+Jun 2027
+
+: Comunidades e Servidores Sustentáveis
+
+Lançamento dos Créditos da Comunidade
+
+Dez 2027
+
+: Faça Suas Comunidades Crescerem
+
+Ferramentas para promover suas comunidades
+
+[Grupos de usuários do SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Participe das Comunidades SimpleX
+
+Mais de 2 milhões de pessoas baixaram os aplicativos SimpleX.
+
+Encontre seus canais e comunidades no diretório e crie os seus próprios!
+
+[Ver diretório do SimpleX](https://simplex.chat/directory)
diff --git a/pt_BR/invitation.md b/pt_BR/invitation.md
new file mode 100644
index 0000000000..37fab7724d
--- /dev/null
+++ b/pt_BR/invitation.md
@@ -0,0 +1,66 @@
+# Você recebeu um link único para se conectar no SimpleX Chat
+
+## Leia o QR code com o aplicativo SimpleX Chat em seu telefone ou tablet.
+
+As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página — eles estão contidos no fragmento de hash do URL do link.
+
+Ainda não baixou o SimpleX Chat?
+
+Use os links abaixo para baixar o aplicativo.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Escanear o QR code do aplicativo
+
+# Você recebeu um link único para se conectar no SimpleX Chat
+
+Para estabelecer uma conexão:
+
+Instale o aplicativo SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid)
+
+1
+
+Conectar no aplicativo
+
+Abra o aplicativo Simplex
+
+2
+
+Toque no botão "conectar" no aplicativo
+
+3
+
+## Escaneie o QR code com o aplicativo SimpleX Chat
+
+As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página —
+eles estão contidos no fragmento de hash do URL do link.
+
+## Instalação do SimpleX chat para o terminal
+
+Use esse comando:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Veja o SimpleX Chat Repositório no GitHub para as instruções sobre como fazer download ou compilá-lo a partir do código-fonte.
+
+---
+
+## Se você já instalou o SimpleX Chat para o terminal
+
+Se você já instalou SimpleX Chat para terminal v1.0.0+, copie o comando abaixo e use-o no bate-papo:
+
+## Junte-se ao SimpleX
+
+Convidamos você a participar da conversa
+
+[Junte-se à comunidade no REDDIT](https://www.reddit.com/r/SimpleXChat/) [Junte-se a nós no GitHub](https://github.com/simplex-chat) [Doe aqui para nos ajudar](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Inscreva-se para receber nossas atualizações
+
+---
+
+Obtenha o SimpleX [aplicativo desktop](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/pt_BR/fdroid)
diff --git a/pt_BR/invitation/index.html b/pt_BR/invitation/index.html
index 7c614fdc8b..333285ad34 100644
--- a/pt_BR/invitation/index.html
+++ b/pt_BR/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Você recebeu um link único para se conectar no SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Leia o QR code com o aplicativo SimpleX Chat em seu telefone ou tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página — eles estão contidos no fragmento de hash do URL do link.
+                As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página &mdash; eles estão contidos no fragmento de hash do URL do link.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ainda não baixou o SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use os links abaixo para baixar o aplicativo.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Instale o aplicativo SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Toque no botão <span class="text-active-blue">"conectar"</span> no aplicativo</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Toque no botão <span class='text-active-blue'>"conectar"</span> no aplicativo</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Escaneie o QR code com o aplicativo SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página —<br> eles estão contidos no fragmento de hash do URL do link.
+                            As chaves públicas e o endereço da fila de mensagens nesse link NÃO são enviados pela rede quando você visualiza essa página &mdash;<br> eles estão contidos no fragmento de hash do URL do link.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Instalação do SimpleX chat para o terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Repositório no GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Se você já instalou o SimpleX Chat para o terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Inscreva-se para receber nossas atualizações</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Digite seu endereço de email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Obtenha o SimpleX <a href="/downloads">aplicativo desktop</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/pt_BR/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/pt_BR/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pt_BR/messaging.md b/pt_BR/messaging.md
new file mode 100644
index 0000000000..b28834e597
--- /dev/null
+++ b/pt_BR/messaging.md
@@ -0,0 +1,253 @@
+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Por que o SimpleX é único
+
+### Você tem privacidade total
+
+O SimpleX protege a privacidade do seu perfil, contatos e metadados, ocultando-os dos servidores da rede SimpleX e de quaisquer observadores.
+
+Diferente de qualquer outra rede de mensagens existente, o SimpleX não tem identificadores atribuídos aos usuários — **nem mesmo números aleatórios**.
+
+### Você está protegido contra spam e abusos
+
+Como você não tem um identificador ou endereço fixo na rede SimpleX, ninguém pode entrar em contato com você, a menos que você compartilhe um endereço de usuário único ou temporário, como um QR code ou um link.
+
+### Você controla seus dados
+
+O SimpleX armazena todos os dados do usuário nos dispositivos clientes em um **formato de banco de dados criptografado portátil** — que pode ser transferido para outro dispositivo.
+
+As mensagens criptografadas de ponta-a-ponta são mantidas temporariamente nos servidores de retransmissão SimpleX até serem recebidas e, em seguida, são excluídas permanentemente.
+
+### Sua própria rede SimpleX
+
+A rede SimpleX é totalmente descentralizada e independente de qualquer criptomoeda ou de qualquer outra rede, exceto a Internet.
+
+Você pode **usar o SimpleX com seus próprios servidores** ou com os servidores fornecidos por nós — e ainda assim se conectar a qualquer usuário.
+
+# Privacidade total de sua identidade, perfil, contatos e metadados
+
+Ao contrário de outras redes de mensagens, o SimpleX **não tem identificadores atribuídos aos usuários**. Ele não depende de números de telefone, endereços baseados em domínio (como email ou XMPP), nomes de usuário, chaves públicas ou mesmo números aleatórios para identificar seus usuários — Os operadores dos servidores não sabem quantas pessoas usam os servidores SimpleX.
+
+Para entregar mensagens, o SimpleX usa [endereços anônimos em pares](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) de filas de mensagens unidirecionais, separadas para mensagens recebidas e enviadas, geralmente por meio de servidores diferentes.
+
+Esse design protege a privacidade com quem você está se comunicando, ocultando-a dos servidores da rede SimpleX e de quaisquer observadores. Para ocultar seu endereço IP dos servidores, você pode **se conectar aos servidores do SimpleX via Tor**.
+
+# Você está protegido contra spam e abusos
+
+Como você não tem um identificador na rede SimpleX, ninguém pode entrar em contato com você, a menos que compartilhe um endereço de usuário único ou temporário, como um QR code ou um link.
+
+Mesmo com o endereço de usuário opcional, embora ele possa ser usado para enviar solicitações de contato de spam, você pode alterá-lo ou excluí-lo completamente sem perder nenhuma das suas conexões.
+
+# Propriedade, controle e segurança dos seus dados
+
+O SimpleX Chat armazena todos os dados do usuário somente em dispositivos clientes usando um **formato de banco de dados criptografado portátil** que pode ser exportado e transferido para qualquer dispositivo compatível.
+
+As mensagens criptografadas de ponta-a-ponta são mantidas temporariamente nos servidores de retransmissão SimpleX até serem recebidas e, em seguida, são excluídas permanentemente.
+
+Diferente dos servidores de redes federadas (email, XMPP ou Matrix), os servidores SimpleX não armazenam contas de usuários, apenas retransmitem mensagens, protegendo a privacidade de ambas as partes.
+
+Não há identificadores ou texto cifrado em comum entre o tráfego de servidor enviado e recebido — se alguém estiver observando, não poderá determinar facilmente quem se comunica com quem, mesmo que o TLS esteja comprometido.
+
+# Totalmente descentralizado — os usuários são proprietários da rede SimpleX
+
+Você pode **usar o SimpleX com seus próprios servidores** e ainda se comunicar com pessoas que usam os servidores pré-configurados fornecidos por nós.
+
+A rede SimpleX usa um [protocolo aberto](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) e fornece um [SDK para criar bots de chat](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), permitindo a implementação de serviços com os quais os usuários podem interagir por meio dos aplicativos SimpleX Chat — estamos' realmente ansiosos para ver quais serviços SimpleX você pode criar.
+
+Se estiver pensando em desenvolver para a rede SimpleX, por exemplo, o bot de chat para os usuários do aplicativo SimpleX ou a integração da biblioteca SimpleX Chat em seus aplicativos móveis, [entre em contato](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) para qualquer orientação e suporte.
+
+## Recursos
+
+Mensagens criptografadas de ponta-a-ponta com markdown e edição
+
+Criptografia de ponta-a-ponta
+imagens, vídeos e arquivos
+
+Criptografia de ponta-a-ponta descentralizada de grupos — somente os usuários sabem que eles existem
+
+Mensagens de voz criptografadas de ponta-a-ponta
+
+Mensagens que desaparecem
+
+Chamadas de áudio e vídeo
+criptografadas de ponta-a-ponta
+
+Armazenamento do aplicativo criptografado portátil — mova o perfil para outro dispositivo
+
+Modo anônimo —
+único do SimpleX Chat
+
+## O que torna o SimpleX privado
+
+### Identificadores temporários anônimos em pares
+
+O SimpleX usa endereços anônimos temporários em pares e credenciais para cada contato de usuário ou membro de grupo.
+
+Ele permite entregar mensagens sem identificadores de perfil, proporcionando melhor privacidade de metadados do que as alternativas.
+
+### Troca de chaves fora da rede
+
+Muitas plataformas de comunicação são vulneráveis a ataques MITM por servidores ou provedores de rede.
+
+Para evitar isso, os aplicativos SimpleX passam chaves de uso único fora da banda, quando você compartilha um endereço como um link ou um QR code.
+
+### 2 camadas de criptografia ponta-a-ponta
+
+Protocolo de dupla catraca —
+mensagens OTR com Sigilo de Encaminhamento Perfeito (Perfect Forward Secrecy) e recuperação de invasão.
+
+Caixa de criptografia NaCL em cada envio para evitar a correlação de tráfego entre os envios de mensagens se o TLS for comprometido.
+
+### Verificação de integridade da mensagem
+
+Para garantir a integridade, as mensagens são numeradas sequencialmente e incluem o hash da mensagem anterior.
+
+Se alguma mensagem for adicionada, removida ou alterada, o destinatário será alertado.
+
+### Camada adicional de criptografia do servidor
+
+Camada adicional de criptografia de servidor para entrega ao destinatário, para evitar a correlação entre o tráfego de servidor recebido e enviado se o TLS for comprometido.
+
+### Mistura de mensagens para reduzir a correlação
+
+Os servidores SimpleX atuam como nós de mistura de baixa latência — as mensagens de entrada e saída têm ordem diferente.
+
+### Transporte TLS seguro e autenticado
+
+Somente o TLS 1.2/1.3 com algoritmos fortes é usado para conexões cliente-servidor.
+
+A impressão digital do servidor e a vinculação de canais evitam ataques MITM e de repetição.
+
+A retomada da conexão é desativada para evitar ataques à sessão.
+
+### Acesso opcional via Tor
+
+Para proteger seu endereço IP, você pode acessar os servidores por meio do Tor ou de alguma outra rede de sobreposição de transporte.
+
+Para usar o SimpleX via Tor, instale o aplicativo [Orbot](https://guardianproject.info/apps/org.torproject.android/) e ative o proxy SOCKS5 (ou VPN [no iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Envios de mensagens unidirecionais
+
+Cada fila de mensagens transmite mensagens em uma direção, com diferentes endereços de envio e recebimento.
+
+Isso reduz os vetores de ataque, em comparação com os corretores de mensagens tradicionais, e os metadados disponíveis.
+
+### Múltiplas camadas de preenchimento de conteúdos
+
+O SimpleX utiliza preenchimento de conteúdo (padding) em cada camada de criptografia para dificultar ataques baseados no tamanho da mensagem.
+
+Isso faz com que mensagens de tamanhos diferentes tenham a mesma aparência para os servidores e observadores de rede.
+
+## Rede SimpleX
+
+O SimpleX Chat oferece a melhor privacidade ao combinar as vantagens das redes P2P e federadas.
+
+### Diferente das redes P2P
+
+Todas as mensagens são enviadas por meio dos servidores, o que proporciona melhor privacidade de metadados e entrega de mensagens assíncronas confiáveis, além de evitar muitos dos .
+
+# Comparação com protocolos de mensagens P2P
+
+Os protocolos e aplicativos de mensagens [P2P](https://pt.wikipedia.org/wiki/Peer-to-peer) têm vários problemas que os tornam menos confiáveis do que o SimpleX, mais complexos de analisar e vulneráveis a vários tipos de ataque.
+
+1. As redes P2P dependem de alguma variante de [DHT](https://pt.wikipedia.org/wiki/Distributed_hash_table) para rotear mensagens. Os projetos de DHT precisam equilibrar a garantia de entrega e a latência. O SimpleX tem melhor garantia de entrega e menor latência do que o P2P, porque a mensagem pode ser passada de forma redundante por vários servidores em paralelo, usando os servidores escolhidos pelo destinatário. Nas redes P2P, a mensagem é passada por nós *O(log N)* sequencialmente, usando nós escolhidos pelo algoritmo.
+2. O design do SimpleX, ao contrário da maioria das redes P2P, não tem identificadores de usuário globais de qualquer tipo, mesmo temporários, e usa apenas identificadores temporários em pares, proporcionando melhor anonimato e proteção de metadados.
+3. O P2P não resolve o problema do [ataque MITM](https://pt.wikipedia.org/wiki/Ataque_man-in-the-middle), e a maioria das implementações existentes não usa mensagens fora de banda para a troca de chaves inicial. O SimpleX usa mensagens fora de banda ou, em alguns casos, conexões pré-existentes seguras e confiáveis para a troca de chaves inicial.
+4. As implementações de P2P podem ser bloqueadas por alguns provedores de Internet (como o [BitTorrent](https://pt.wikipedia.org/wiki/BitTorrent)). O SimpleX é independente de transporte, podendo funcionar com protocolos padrão da Web, por exemplo, WebSockets.
+5. Todas as redes P2P conhecidas podem ser vulneráveis ao [ataque Sybil](https://pt.wikipedia.org/wiki/Ataque_Sybil), pois cada nó pode ser descoberto e a rede opera como um todo. As medidas conhecidas para combatê-lo exigem um componente centralizado ou uma [prova de trabalho](https://pt.wikipedia.org/wiki/Prova_de_trabalho) cara. A rede SimpleX não tem capacidade de descoberta de servidor, é fragmentada e opera como várias sub-redes isoladas, impossibilitando ataques em toda a rede.
+6. As redes P2P podem ser vulneráveis a [ataques DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), quando os clientes podem retransmitir e amplificar o tráfego, resultando em uma negação de serviço em toda a rede. Os clientes SimpleX apenas retransmitem o tráfego de uma conexão conhecida e não podem ser usados por um invasor para amplificar o tráfego em toda a rede.
+
+---
+
+### Diferente das redes federadas
+
+Os servidores de retransmissão SimpleX NÃO armazenam perfis de usuário, contatos e mensagens entregues, NÃO se conectam uns aos outros e NÃO há diretório de servidores.
+
+---
+
+### Rede SimpleX
+
+Os servidores fornecem filas unidirecionais para conectar os usuários, mas não têm visibilidade do gráfico de conexão de rede — somente os usuários têm.
+
+## Explicação do SimpleX
+
+1. O que os usuários experimentam
+
+2. Como funciona
+
+3. O que os servidores veem
+
+1. O que os usuários experimentam
+
+Você pode criar contatos e grupos e ter conversas bidirecionais, como em qualquer outro mensageiro.
+
+Como ele pode funcionar com filas unidirecionais e sem identificadores de perfil de usuário?
+
+2. Como funciona
+
+Para cada conexão, são usadas duas filas de mensagens separadas para enviar e receber mensagens por meio de servidores diferentes.
+
+Os servidores só passam mensagens em uma direção, sem ter a imagem completa da conversa ou conexões do usuário.
+
+3. O que os servidores veem
+
+Os servidores têm credenciais anônimas separadas para cada envio e não sabem a que usuários elas pertencem.
+
+Os usuários podem melhorar ainda mais a privacidade de metadados usando o Tor para acessar os servidores, impedindo a correlação pelo endereço de IP.
+
+## Comparação com outros protocolos
+
+|  |  | Signal, grandes plataformas | Matrix, XMPP | Protocolos P2P |
+| --- | --- | --- | --- | --- |
+| Requer uma identidade global | Não - privado | Sim [1] | Sim [2] | Sim [3] |
+| Possibilidade de MITM | Não - seguro [4] | Sim [5] | Sim | Sim |
+| Dependência do DNS | Não - resiliente | Sim | Sim | Não |
+| Rede única ou centralizada | Não - descentralizado | Sim | Não - federado [6] | Sim [7] |
+| Componente central ou outro ataque em toda a rede | Não - resiliente | Sim | Sim [2] | Sim [8] |
+
+---
+
+1. Geralmente com base em um número de telefone, em alguns casos em nomes de usuário
+2. Endereços baseados no DNS
+3. Chave pública ou alguma outra ID globalmente exclusiva
+4. Os relays SimpleX não podem comprometer a criptografia e2e. Verifique o código de segurança para mitigar ataques em canais fora de banda
+5. Se os servidores da operadora forem comprometidos. Verifique o código de segurança no Signal e outros aplicativos para mitigá-lo
+6. Não protege a privacidade da metadados dos usuários
+7. Embora os P2P sejam distribuídos, eles não são federados &mdash - operam como uma única rede
+8. As redes P2P têm uma autoridade central ou toda a rede pode ser comprometida — [veja aqui](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparação da segurança da criptografia de ponta a ponta em diferentes mensageiros
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Preenchimento de mensagem | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repúdio (negação plausível) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Sigilo de Encaminhamento | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Segurança pós-comprometimento | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| Troca de chaves de dois fatores | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Criptografia híbrida pós-quântica | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. O Briar preenche as mensagens até que o tamanho seja arredondado para 1024 bytes, enquanto o Signal as preenche para 160 bytes
+2. O repúdio não inclui a conexão cliente-servidor.
+3. Parece que o uso de assinaturas criptográficas compromete o repúdio (denegabilidade), mas isso precisa ser esclarecido.
+4. A implementação de múltiplos dispositivos compromete a segurança pós-comprometimento do Double Ratchet — [veja aqui](https://eprint.iacr.org/2021/626.pdf).
+5. A troca de chaves de dois fatores é opcional por meio da verificação do código de segurança.
+6. O acordo de chaves pós-quântico é 'esparso' — ele protege apenas algumas das etapas da catraca (ratchet).
diff --git a/pt_BR/messaging/index.html b/pt_BR/messaging/index.html
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@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você tem privacidade total</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você está protegido<br>contra spam e abusos</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você controla seus dados</h3>
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@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sua própria rede SimpleX</h3>
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@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Ele permite entregar mensagens sem identificadores de perfil, proporcionando melhor privacidade de metadados do que as alternativas.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Para evitar isso, os aplicativos SimpleX passam chaves de uso único fora da banda, quando você compartilha um endereço como um link ou um QR code.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Caixa de criptografia NaCL em cada envio para evitar a correlação de tráfego entre os envios de mensagens se o TLS for comprometido.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Se alguma mensagem for adicionada, removida ou alterada, o destinatário será alertado.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Camada adicional de criptografia de servidor para entrega ao destinatário, para evitar a correlação entre o tráfego de servidor recebido e enviado se o TLS for comprometido.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Os servidores SimpleX atuam como nós de mistura de baixa latência — as mensagens de entrada e saída têm ordem diferente.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">A retomada da conexão é desativada para evitar ataques à sessão.</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Para usar o SimpleX via Tor, instale o aplicativo <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot</a> e ative o proxy SOCKS5 (ou VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">no iOS</a>).</p>
                             
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-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Toque para fechar</p>
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@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Isso reduz os vetores de ataque, em comparação com os corretores de mensagens tradicionais, e os metadados disponíveis.</p>
                             
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@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Isso faz com que mensagens de tamanhos diferentes tenham a mesma aparência para os servidores e observadores de rede.</p>
                             
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 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
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+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você tem privacidade total</h3>
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@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você está protegido<br>contra spam e abusos</h3>
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@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Você controla seus dados</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Sua própria rede SimpleX</h3>
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@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/pt_BR/why.md b/pt_BR/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/pt_BR/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/pt_BR/why/index.html b/pt_BR/why/index.html
index c9866fc802..49d4f33260 100644
--- a/pt_BR/why/index.html
+++ b/pt_BR/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/pt_BR/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/reproduce.md b/reproduce.md
new file mode 100644
index 0000000000..af38cfb966
--- /dev/null
+++ b/reproduce.md
@@ -0,0 +1,197 @@
+# Verifying and reproducing release builds
+
+- [Obtain release signing key](#obtain-release-signing-key)
+- [Verify release signature](#verify-release-signature)
+- [How to reproduce builds](#how-to-reproduce-builds)
+   - [Server binaries](#server-binaries)
+   - [Linux desktop apps and CLI](#linux-desktop-apps-and-cli)
+   - [Android apps](#android-apps)
+
+## Obtain release signing key
+
+To verify the signature of `_sha256sums` or apks you need to obtain the signing key. You can do it from keyservers:
+
+```sh
+gpg --keyserver hkps://keys.openpgp.org --search build@simplex.chat
+gpg --keyserver hkps://keyserver.ubuntu.com --search build@simplex.chat
+```
+
+```sh
+gpg --list-keys build@simplex.chat
+```
+
+Once you obtain the signing key, verify that its fingerprint is:
+
+```
+BBDF 7BDA D154 8B16 836A F5B9 D53B DFD1 53C3 66BA
+```
+
+Additionally, compare the key fingerprint with:
+
+- [simplexchat.eth](https://app.ens.domains/simplexchat.eth) (release key record)
+- [Mastodon](https://mastodon.social/@simplex) (profile)
+- [Reddit](https://www.reddit.com/r/SimpleXChat/) (side panel)
+
+You can set the imported key as "ultimately trusted":
+
+```sh
+echo -e "trust\n5\ny\nquit" | gpg --command-fd 0 --edit-key build@simplex.chat
+```
+
+## Verify release signature
+
+**Linux desktop apps and CLI**:
+
+Download the file with executable hashes and the signature. For example, to verify the `v6.5.0-beta.3` release:
+
+```sh
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/_sha256sums.asc'
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/_sha256sums'
+```
+
+Verify the signature:
+
+```sh
+gpg --verify _sha256sums.asc _sha256sums
+```
+
+**Android APKs**:
+
+Download the APK files and signatures. For example, to verify the `v6.5.0-beta.3` release:
+
+```sh
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/simplex-aarch64.apk'
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/_simplex-aarch64.apk.asc'
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/simplex-armv7a.apk'
+curl -LO 'https://github.com/simplex-chat/simplex-chat/releases/download/v6.5.0-beta.3/_simplex-armv7a.apk.asc'
+```
+
+Verify the signatures:
+
+```sh
+gpg --verify _simplex-armv7a.apk.asc simplex-armv7a.apk
+gpg --verify _simplex-aarch64.apk.asc simplex-aarch64.apk
+```
+
+## How to reproduce builds
+
+To reproduce the build you must have:
+
+- Linux machine
+- `x86-64` architecture
+- Installed `docker`, `curl` and `git`
+
+### Server binaries
+
+1. Download script:
+
+   ```sh
+   curl -LO 'https://raw.githubusercontent.com/simplex-chat/simplexmq/refs/heads/master/scripts/simplexmq-reproduce-builds.sh'
+   ```
+
+2. Make it executable:
+
+   ```sh
+   chmod +x simplexmq-reproduce-builds.sh
+   ```
+
+3. Execute the script with the required tag:
+
+   ```sh
+   ./simplexmq-reproduce-builds.sh 'v6.3.1'
+   ```
+
+   The script executes these steps (please review the script to confirm):
+
+   1) builds all server binaries for the release in docker container.
+   2) downloads binaries from the same GitHub release and compares them with the built binaries.
+   3) if they all match, generates _sha256sums file with their checksums.
+
+   This will take a while.
+
+4. After compilation, you should see the folder named as the tag and repository name (e.g., `v6.3.1-simplexmq`) with two subfolders:
+
+   ```sh
+   ls v6.3.1-simplexmq
+   ```
+
+   ```sh
+   from-source  prebuilt  _sha256sums
+   ```
+
+   The file _sha256sums contains the hashes of all builds - you can compare it with the same file in GitHub release.
+
+### Linux desktop apps and CLI
+
+1. Download script:
+
+   ```sh
+   curl -LO 'https://raw.githubusercontent.com/simplex-chat/simplex-chat/refs/heads/master/scripts/simplex-chat-reproduce-builds.sh'
+   ```
+
+2. Make it executable:
+
+   ```sh
+   chmod +x simplex-chat-reproduce-builds.sh
+   ```
+
+3. Execute the script with the required tag:
+
+   ```sh
+   ./simplex-chat-reproduce-builds.sh 'v6.4.8'
+   ```
+
+   The script executes these steps (please review the script to confirm):
+
+   1) builds all Linux CLI and Desktop binaries for the release in docker container.
+   2) downloads binaries from the same GitHub release and compares them with the built binaries.
+   3) if they all match, generates _sha256sums file with their checksums.
+
+   This will take a while.
+
+4. After compilation, you should see the folder named as the tag and repository name (e.g., `v6.4.8-simplex-chat`) with two subfolders:
+
+   ```sh
+   ls v6.4.8-simplex-chat
+   ```
+
+   ```sh
+   from-source  prebuilt  _sha256sums
+   ```
+
+   The file _sha256sums contains the hashes of all builds - you can compare it with the same file in GitHub release.
+
+### Android apps
+
+In addition to basic requirements, Android build will:
+
+- Take ~150gb of disc space
+- Take ~20h to build all the architectures (depends on core count)
+- Require at least 16gb of RAM
+
+1. Download script:
+
+   ```sh
+   curl -LO 'https://raw.githubusercontent.com/simplex-chat/simplex-chat/refs/heads/master/scripts/simplex-chat-reproduce-builds-android.sh'
+   ```
+
+2. Make it executable:
+
+   ```sh
+   chmod +x simplex-chat-reproduce-builds-android.sh
+   ```
+
+3. Execute the script with the required tag:
+
+   ```sh
+   ./simplex-chat-reproduce-builds-android.sh 'v6.5.0-beta.3'
+   ```
+
+   The script executes these steps (please review the script to confirm):
+
+   1) Downloads and checks that APKs from GitHub are signed with valid key.
+   2) Builds Android APKs in a docker container.
+   3) Compares the releases by copying the signature from downloaded APKs to locally built APKs.
+   4) If the resulting build is bit-by-bit identical, prints the message that this tag was reproduced.
+
+   This will take a while.
diff --git a/reproduce/index.html b/reproduce/index.html
index 16666ae90e..15ed45a99d 100644
--- a/reproduce/index.html
+++ b/reproduce/index.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/reproduce.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/ro/contact.md b/ro/contact.md
new file mode 100644
index 0000000000..c9ba126c0a
--- /dev/null
+++ b/ro/contact.md
@@ -0,0 +1,66 @@
+# You received an address to connect on SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# You received an address to connect on SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid)
diff --git a/ro/contact/index.html b/ro/contact/index.html
index 086cb096a6..bbcfc0f6dd 100644
--- a/ro/contact/index.html
+++ b/ro/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">You received an address to connect on SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ro/fdroid.md b/ro/fdroid.md
new file mode 100644
index 0000000000..296adf884e
--- /dev/null
+++ b/ro/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat repo
+
+Stable and beta versions built by the developers
+
+To add it to your F-Droid client, scan the QR code or use this URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Signing key fingerprint (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Stable versions built by F-Droid.org
+
+The releases to this repo are done several days later.
+
+SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please [export](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) the chat database and re-install the app.
diff --git a/ro/fdroid/index.html b/ro/fdroid/index.html
index a661d7da49..066ff157dd 100644
--- a/ro/fdroid/index.html
+++ b/ro/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -693,15 +698,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
                         <p>To add it to your F-Droid client, <span class="hide-on-mobile">scan the QR code or</span> use this URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Signing key fingerprint (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,7 +718,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Stable versions built by F-Droid.org</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
                 <p class="mb-2">SimpleX Chat and F-Droid.org repositories sign builds with the different keys. To switch, please <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">export</a> the chat database and re-install the app.</p>
@@ -720,17 +726,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ro/file.md b/ro/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/ro/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/ro/file/index.html b/ro/file/index.html
index 96bba809b0..88f8baf8b4 100644
--- a/ro/file/index.html
+++ b/ro/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
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+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/ro/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/ro/index.md b/ro/index.md
new file mode 100644
index 0000000000..bf12425ccd
--- /dev/null
+++ b/ro/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Learn more.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/ro/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/ro/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/ro/why)
+
+## Finanțat de utilizatorii săi
+
+Pentru a rămâne independente, canalele și comunitățile mari vor plăti pentru serverele lor.
+
+Iar utilizatorii pot acum investi în SimpleX Chat — finanțarea participativă este activă!
+
+[Investește în SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/ro/invitation.md b/ro/invitation.md
new file mode 100644
index 0000000000..2706ffc360
--- /dev/null
+++ b/ro/invitation.md
@@ -0,0 +1,66 @@
+# Ai primit un link de unică folosință pentru a te conecta pe SimpleX Chat
+
+## Scan the QR code with the SimpleX Chat app on your phone or tablet.
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+
+Not downloaded the SimpleX Chat yet?
+
+Use the links below to download the app.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Scan QR code from mobile app
+
+# Ai primit un link de unică folosință pentru a te conecta pe SimpleX Chat
+
+To make a connection:
+
+Install SimpleX app
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid)
+
+1
+
+Connect in app
+
+Open SimpleX app
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## Scan the QR code with the SimpleX Chat app
+
+The public keys and message queue address in this link are NOT sent over the network when you view this page —
+they are contained in the hash fragment of the link URL.
+
+## Installing SimpleX chat to terminal
+
+Use this command:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## If you already installed SimpleX Chat for the terminal
+
+If you already installed SimpleX Chat for the terminal v1.0.0+, copy the command below and use it in the chat:
+
+## Join SimpleX
+
+We invite you to join the conversation
+
+[Join the REDDIT community](https://www.reddit.com/r/SimpleXChat/) [Join us on GitHub](https://github.com/simplex-chat) [Donate here to help us](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Sign up to receive our updates
+
+---
+
+Get SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ro/fdroid)
diff --git a/ro/invitation/index.html b/ro/invitation/index.html
index 5ebf38a264..c7f9e3ad78 100644
--- a/ro/invitation/index.html
+++ b/ro/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Ai primit un link de unică folosință pentru a te conecta pe SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Scan the QR code with the SimpleX Chat app on your phone or tablet.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                The public keys and message queue address in this link are NOT sent over the network when you view this page — they are contained in the hash fragment of the link URL.
+                The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash; they are contained in the hash fragment of the link URL.
             </p>
             <p class="text-grey-black dark:text-white text-base">Not downloaded the SimpleX Chat yet?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Use the links below to download the app.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Install SimpleX app</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Scan the QR code with the SimpleX Chat app</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            The public keys and message queue address in this link are NOT sent over the network when you view this page —<br> they are contained in the hash fragment of the link URL.
+                            The public keys and message queue address in this link are NOT sent over the network when you view this page &mdash;<br> they are contained in the hash fragment of the link URL.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Installing SimpleX chat to terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">If you already installed SimpleX Chat for the terminal</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Sign up to receive our updates</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Enter your email address">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Get SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ro/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ro/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ro/messaging.md b/ro/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Why SimpleX is unique
+
+### You have complete privacy
+
+SimpleX protects the privacy of your profile, contacts and metadata, hiding it from SimpleX network servers and any observers.
+
+Unlike any other existing messaging network, SimpleX has no identifiers assigned to the users — **not even random numbers**.
+
+### You are protected from spam and abuse
+
+Because you have no identifier or fixed address on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+### You control your data
+
+SimpleX stores all user data on client devices in a **portable encrypted database format** — it can be transferred to another device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+### You own SimpleX network
+
+The SimpleX network is fully decentralised and independent of any crypto-currency or any other network, other than the Internet.
+
+You can **use SimpleX with your own servers** or with the servers provided by us — and still connect to any user.
+
+# Full privacy of your identity, profile, contacts and metadata
+
+Unlike other messaging networks, SimpleX has **no identifiers assigned to the users**. It does not rely on phone numbers, domain-based addresses (like email or XMPP), usernames, public keys or even random numbers to identify its users — SimpleX server operators don't know how many people use their servers.
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# The best protection from spam and abuse
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# Ownership, control and security of your data
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+There are no identifiers or ciphertext in common between sent and received server traffic — if anybody is observing it, they cannot easily determine who communicates with whom, even if TLS is compromised.
+
+# Fully decentralised — users own the SimpleX network
+
+You can **use SimpleX with your own servers** and still communicate with people who use the servers preconfigured in the apps.
+
+SimpleX network uses an [open protocol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) and provides [SDK to create chat bots](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), allowing implementation of services that users can interact with via SimpleX Chat apps — we're really looking forward to seeing what SimpleX services you will build.
+
+If you are considering developing for the SimpleX network, for example, the chat bot for SimpleX app users, or the integration of the SimpleX Chat library into your mobile apps, please [get in touch](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) for any advice and support.
+
+## ­Funcționalități
+
+Mesaje criptate E2E, cu formatare Markdown și editare
+
+Imagini, videoclipuri și fișiere
+criptate E2E
+
+Grupuri descentralizate criptate E2E — doar utilizatorii știu că există
+
+Mesaje vocale criptate E2E
+
+Mesaje care dispar
+
+Apeluri audio și video
+criptate E2E
+
+Stocare portabilă criptată a aplicației — mută profilul pe alt dispozitiv
+
+Mod incognito —
+unic în SimpleX Chat
+
+## What makes SimpleX private
+
+### Temporary anonymous pairwise identifiers
+
+SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member.
+
+It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.
+
+### Schimb de chei în afara benzii
+
+Many communication networks are vulnerable to MITM attacks by servers or network providers.
+
+To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.
+
+### 2 straturi de criptare end-to-end
+
+Double-ratchet protocol —
+OTR messaging with perfect forward secrecy and break-in recovery.
+
+NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.
+
+### Verificarea integrității mesajului
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### Strat adițional de criptare pe server
+
+Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.
+
+### Amestecare mesaje pentru a reduce corelația
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### Transport TLS securizat și autentificat
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+Connection resumption is disabled to prevent session attacks.
+
+### Acces opțional prin Tor
+
+To protect your IP address you can access the servers via Tor or some other transport overlay network.
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Unidirectional message queues
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+It reduces the attack vectors, compared with traditional message brokers, and available meta-data.
+
+### Straturi multiple de padding al conținutului
+
+SimpleX uses content padding for each encryption layer to frustrate message size attacks.
+
+It makes messages of different sizes look the same to the servers and network observers.
+
+## SimpleX Network
+
+SimpleX Chat provides the best privacy by combining the advantages of P2P and federated networks.
+
+### Unlike P2P networks
+
+All messages are sent via the servers, both providing better metadata privacy and reliable asynchronous message delivery, while avoiding many .
+
+# Comparație cu protocoalele de mesagerie P2P
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messaging protocols and apps have various problems that make them less reliable than SimpleX, more complex to analyse, and vulnerable to several types of attack.
+
+1. P2P networks rely on some variant of [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) to route messages. DHT designs have to balance delivery guarantee and latency. SimpleX has both better delivery guarantee and lower latency than P2P, because the message can be redundantly passed via several servers in parallel, using the servers chosen by the recipient. In P2P networks the message is passed through *O(log N)* nodes sequentially, using nodes chosen by the algorithm.
+2. SimpleX design, unlike most P2P networks, has no global user identifiers of any kind, even temporary, and only uses temporary pairwise identifiers, providing better anonymity and metadata protection.
+3. P2P does not solve [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problem, and most existing implementations do not use out-of-band messages for the initial key exchange. SimpleX uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### Unlike federated networks
+
+SimpleX relay servers do NOT store user profiles, contacts and delivered messages, do NOT connect to each other, and there is NO servers directory.
+
+---
+
+### SimpleX network
+
+servers provide unidirectional queues to connect the users, but they have no visibility of the network connection graph — only the users do.
+
+## SimpleX, explicat
+
+1. Ce experimentează utilizatorii
+
+2. Cum funcționează
+
+3. Ce văd serverele
+
+1. Ce experimentează utilizatorii
+
+Poți crea contacte și grupuri, și poți avea conversații bidirecționale, ca în oricare altă aplicație de mesagerie.
+
+Cum poate funcționa cu liste de așteptare unidirecționale și fără identificatori de profil ai utilizatorului?
+
+2. Cum funcționează
+
+Pentru fiecare conexiune, folosești două cozi de mesaje separate pentru a trimite și a primi mesaje prin servere diferite.
+
+Serverele doar transmit mesaje într-un singur sens, fără a deține imaginea de ansamblu a conversațiilor sau a conexiunilor utilizatorului.
+
+3. Ce văd serverele
+
+Serverele au credențiale anonime separate pentru fiecare coadă și nu știu cui aparțin acestea.
+
+Utilizatorii pot îmbunătăți și mai mult confidențialitatea metadatelor folosind Tor pentru a accesa serverele, prevenind astfel corelarea prin adresa IP.
+
+## Comparison with other protocols
+
+|  |  | Signal, big platforms | XMPP, Matrix | P2P protocols |
+| --- | --- | --- | --- | --- |
+| Requires global identity | No - private | Yes [1] | Yes [2] | Yes [3] |
+| Possibility of MITM | No - secure [4] | Yes [5] | Yes | Yes |
+| Dependence on DNS | No - resilient | Yes | Yes | No |
+| Single or centralized network | No - decentralized | Yes | No - federated [6] | Yes [7] |
+| Central component or other network-wide attack | No - resilient | Yes | Yes [2] | Yes [8] |
+
+---
+
+1. Usually based on a phone number, in some cases on usernames
+2. DNS-based addresses
+3. Public key or some other globally unique ID
+4. SimpleX relays cannot compromise e2e encryption. Verify security code to mitigate attack on out-of-band channel
+5. If operator's servers are compromised. Verify security code in Signal and some other apps to mitigate it
+6. Does not protect users' metadata privacy
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. P2P networks either have a central authority or the whole network can be compromised — [see here](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [see here](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/ro/messaging/index.html b/ro/messaging/index.html
index 3edb803e3a..3fa7e47e3c 100644
--- a/ro/messaging/index.html
+++ b/ro/messaging/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It allows messages to be delivered without user profile identifiers, providing better meta-data privacy than alternatives.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1236,7 +1240,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1254,7 +1258,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1270,7 +1274,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Additional layer of server encryption for delivery to the recipient, to prevent the correlation between received and sent server traffic if TLS is compromised.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1286,7 +1290,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1306,7 +1310,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Connection resumption is disabled to prevent session attacks.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1342,7 +1346,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It reduces the attack vectors, compared with traditional message brokers, and available meta-data.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1360,7 +1364,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">It makes messages of different sizes look the same to the servers and network observers.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Tap to close</p>
                     </div>
                 </div>
                 
@@ -1842,17 +1846,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
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+<link rel="describedby" href="/llms.txt"/>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You have complete privacy</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You are protected<br>from spam and abuse</h3>
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@@ -1188,7 +1192,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You control your data</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">You own SimpleX network</h3>
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@@ -2150,17 +2154,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="tooltip-blockchain" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Blockchain</h4><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="blockchain">Read more</button></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-break-in-recovery" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Break-in recovery</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-centralized-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Centralized network</h4><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-content-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Content padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="content-padding">Read more</button></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-overlay-network" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Overlay network</h4><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="overlay-network">Read more</button></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ro/why.md b/ro/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/ro/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/ro/why/index.html b/ro/why/index.html
index 04e038d08d..970eebf12b 100644
--- a/ro/why/index.html
+++ b/ro/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ro/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/robots.txt b/robots.txt
new file mode 100644
index 0000000000..7caaf2e3b8
--- /dev/null
+++ b/robots.txt
@@ -0,0 +1,4 @@
+User-agent: *
+Allow: /
+
+Sitemap: https://simplex.chat/sitemap.xml
diff --git a/ru/contact.md b/ru/contact.md
new file mode 100644
index 0000000000..8aee56188a
--- /dev/null
+++ b/ru/contact.md
@@ -0,0 +1,66 @@
+# Вы получили адрес контакта для соединения в SimpleX Chat
+
+## Отсканируйте QR-код с помощью приложения SimpleX Chat на Вашем телефоне или планшете.
+
+Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы — они содержатся в хеш-фрагменте URL-адреса ссылки.
+
+Еще не скачали SimpleX Chat?
+
+Используйте ссылки ниже, чтобы загрузить приложение.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Отсканируйте QR-код в мобильном приложении
+
+# Вы получили адрес контакта для соединения в SimpleX Chat
+
+Чтобы установить соединение:
+
+Установите приложение SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid)
+
+1
+
+Подключитесь в приложении
+
+Откройте приложение SimpleX
+
+2
+
+Нажмите на кнопку ’подключиться’ в приложении
+
+3
+
+## Отсканируйте QR-код с помощью приложения SimpleX Chat
+
+Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы —
+они содержатся в хеш-фрагменте URL-адреса ссылки.
+
+## Установка SimpleX Chat в терминале
+
+Используйте эту команду:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Инструкции по загрузке или компиляции SimpleX Chat из исходного кода приведены в репозитории GitHub SimpleX Chat.
+
+---
+
+## Если Вы уже установили SimpleX Chat для терминала
+
+Если Вы уже установили SimpleX Chat для терминала v1.0.0+, скопируйте приведенную ниже команду и используйте ее в чате:
+
+## Присоединяйтесь к SimpleX
+
+Мы приглашаем Вас присоединиться к разговору
+
+[Присоединяйтесь в REDDIT](https://www.reddit.com/r/SimpleXChat/) [Присоединяйтесь на GitHub](https://github.com/simplex-chat) [Пожертвовать](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Подпишитесь на нашу рассылку новостей
+
+---
+
+Скачать SimpleX [для компьютера](https://simplex.chat/downloads/#desktop-app)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid)
diff --git a/ru/contact/index.html b/ru/contact/index.html
index 883a3cb73d..e80d84187f 100644
--- a/ru/contact/index.html
+++ b/ru/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Вы получили адрес контакта для соединения в SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Отсканируйте QR-код с помощью приложения SimpleX Chat на Вашем телефоне или планшете.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы — они содержатся в хеш-фрагменте URL-адреса ссылки.
+                Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы &mdash; они содержатся в хеш-фрагменте URL-адреса ссылки.
             </p>
             <p class="text-grey-black dark:text-white text-base">Еще не скачали SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Используйте ссылки ниже, чтобы загрузить приложение.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Установите приложение SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Нажмите на кнопку <span class="text-active-blue">’подключиться’</span> в приложении</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Нажмите на кнопку <span class='text-active-blue'>’подключиться’</span> в приложении</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Отсканируйте QR-код с помощью приложения SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы —<br> они содержатся в хеш-фрагменте URL-адреса ссылки.
+                            Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы &mdash;<br> они содержатся в хеш-фрагменте URL-адреса ссылки.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Установка SimpleX Chat в терминале</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">репозитории GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Если Вы уже установили SimpleX Chat для терминала</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Подпишитесь на нашу рассылку новостей</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введите Ваш адрес Email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Скачать SimpleX <a href="/downloads/#desktop-app">для компьютера</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ru/fdroid.md b/ru/fdroid.md
new file mode 100644
index 0000000000..68a6d52849
--- /dev/null
+++ b/ru/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat в F-Droid
+
+### Репозиторий SimpleX Chat
+
+Стабильные и бета-версии, созданные разработчиками
+
+Чтобы добавить его в свой клиент F-Droid, отсканируйте QR-код или используйте этот адрес:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Идентификатор ключа подписи (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Репозиторий F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Стабильные версии, созданные F-Droid.org
+
+Новые версии в этом репозитории публикуются с задержкой в несколько дней.
+
+Приложение SimpleX Chat от разработчиков и от репозитория F-Droid.org имеют разные ключи подписи. Если Вы хотите сменить одно на другое, Вам сначала нужно будет [экспортировать](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) базу данных и только потом скачать другое приложение.
diff --git a/ru/fdroid/index.html b/ru/fdroid/index.html
index 78734febd1..5db142ed43 100644
--- a/ru/fdroid/index.html
+++ b/ru/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat в F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Стабильные и бета-версии, созданные разработчиками</p>
-                        <p>Чтобы добавить его в свой клиент F-Droid, <span class="hide-on-mobile">отсканируйте QR-код или </span>используйте этот адрес:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Чтобы добавить его в свой клиент F-Droid, <span class='hide-on-mobile'>отсканируйте QR-код или </span>используйте этот адрес:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Идентификатор ключа подписи (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Репозиторий F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Стабильные версии, созданные F-Droid.org</p>
                 <p class="mb-2">Новые версии в этом репозитории публикуются с задержкой в несколько дней.</p>
-                <p class="mb-2">Приложение SimpleX Chat от разработчиков и от репозитория F-Droid.org имеют разные ключи подписи. Если Вы хотите сменить одно на другое, Вам сначала нужно будет <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">экспортировать</a> базу данных и только потом скачать другое приложение.</p>
+                <p class="mb-2">Приложение SimpleX Chat от разработчиков и от репозитория F-Droid.org имеют разные ключи подписи. Если Вы хотите сменить одно на другое, Вам сначала нужно будет <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>экспортировать</a> базу данных и только потом скачать другое приложение.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ru/file.md b/ru/file.md
new file mode 100644
index 0000000000..93b55d37fc
--- /dev/null
+++ b/ru/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Отправьте файлы безопасно со сквозным шифрованием — без учётных записей, без отслеживания.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/ru/file/index.html b/ru/file/index.html
index f0bad35c14..87c8609fc1 100644
--- a/ru/file/index.html
+++ b/ru/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ru/index.html b/ru/index.html
index 4b68719662..639332a71b 100644
--- a/ru/index.html
+++ b/ru/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/ru/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/ru/fdroid" title="Загрузить через F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Бета-релиз для iOS на TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="Бета-релиз для iOS на TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Аудиты безопасности" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Сейчас</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Июнь 2027</span>
diff --git a/ru/index.md b/ru/index.md
new file mode 100644
index 0000000000..052818f2cd
--- /dev/null
+++ b/ru/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Будь Свободен
+
+## В Своей Сети
+
+Первая сеть без идентификаторов пользователей.
+Ваши контакты, группы и каналы принадлежат Вам.
+
+Invest in SimpleX Chat. [Узнать больше.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [Загрузить через F-Droid](https://simplex.chat/ru/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Аудиты безопасности](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Аудиты
+безопасности
+
+[Рекомендации мессенджеров Privacy Guides](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Рекомендации мессенджеров от Whonix](https://www.whonix.org/wiki/Chat#Recommendation) [Публикации Heise Online](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Обзор от Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut подкаст интервью](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Никто Не Знает С Кем Вы Общаетесь
+
+Даже серверы – все сообщения выглядят как случайный шум.
+
+Десятки миллионов сообщений доставляются конфиденциально каждый день.
+
+[Узнать больше про сообщения в SimpleX](https://simplex.chat/ru/messaging)
+
+## Сеть Принадлежит Вам
+
+Все контакты и группы хранятся на Вашем устройстве, а не в базе данных сервера.
+
+Ни одна организация не контролирует сеть – каждый может запускать серверы.
+
+[Почему мы это строим](https://simplex.chat/ru/why)
+
+## Финансируется Пользователями
+
+Для сохранения независимости крупные каналы и сообщества будут оплачивать свои серверы.
+
+А теперь пользователи могут инвестировать в SimpleX Chat — краудфандинг запущен!
+
+[Инвестировать в SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## Путь Сети SimpleX к Свободному Интернету
+
+2026
+
+: Большие каналы и группы
+
+Чтобы Вы могли покинуть централизованные платформы
+
+Июнь 2027
+
+: Самодостаточные группы и серверы
+
+Запуск Community Credits
+
+Дек 2027
+
+: Поддержка роста Ваших групп
+
+Инструменты для продвижения групп
+
+[Группа пользователей SimpleX](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Вступайте в Группы SimpleX
+
+Более 2 миллионов человек скачали приложения SimpleX.
+
+Найдите каналы и сообщества в каталоге и создайте свои!
+
+[Открыть каталог SimpleX](https://simplex.chat/directory)
diff --git a/ru/invitation.md b/ru/invitation.md
new file mode 100644
index 0000000000..0e371302da
--- /dev/null
+++ b/ru/invitation.md
@@ -0,0 +1,66 @@
+# Вы получили одноразовую ссылку для соединения в SimpleX Chat
+
+## Отсканируйте QR-код с помощью приложения SimpleX Chat на Вашем телефоне или планшете.
+
+Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы — они содержатся в хеш-фрагменте URL-адреса ссылки.
+
+Еще не скачали SimpleX Chat?
+
+Используйте ссылки ниже, чтобы загрузить приложение.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Отсканируйте QR-код в мобильном приложении
+
+# Вы получили одноразовую ссылку для соединения в SimpleX Chat
+
+Чтобы установить соединение:
+
+Установите приложение SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid)
+
+1
+
+Подключитесь в приложении
+
+Откройте приложение SimpleX
+
+2
+
+Нажмите на кнопку ’подключиться’ в приложении
+
+3
+
+## Отсканируйте QR-код с помощью приложения SimpleX Chat
+
+Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы —
+они содержатся в хеш-фрагменте URL-адреса ссылки.
+
+## Установка SimpleX Chat в терминале
+
+Используйте эту команду:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Инструкции по загрузке или компиляции SimpleX Chat из исходного кода приведены в репозитории GitHub SimpleX Chat.
+
+---
+
+## Если Вы уже установили SimpleX Chat для терминала
+
+Если Вы уже установили SimpleX Chat для терминала v1.0.0+, скопируйте приведенную ниже команду и используйте ее в чате:
+
+## Присоединяйтесь к SimpleX
+
+Мы приглашаем Вас присоединиться к разговору
+
+[Присоединяйтесь в REDDIT](https://www.reddit.com/r/SimpleXChat/) [Присоединяйтесь на GitHub](https://github.com/simplex-chat) [Пожертвовать](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Подпишитесь на нашу рассылку новостей
+
+---
+
+Скачать SimpleX [для компьютера](https://simplex.chat/downloads/#desktop-app)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/ru/fdroid)
diff --git a/ru/invitation/index.html b/ru/invitation/index.html
index 0e29d2267f..964af3ff16 100644
--- a/ru/invitation/index.html
+++ b/ru/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Вы получили одноразовую ссылку для соединения в SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Отсканируйте QR-код с помощью приложения SimpleX Chat на Вашем телефоне или планшете.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы — они содержатся в хеш-фрагменте URL-адреса ссылки.
+                Публичные ключи и адрес очереди сообщений в этой ссылке НЕ отправляются по сети при просмотре этой страницы &mdash; они содержатся в хеш-фрагменте URL-адреса ссылки.
             </p>
             <p class="text-grey-black dark:text-white text-base">Еще не скачали SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Используйте ссылки ниже, чтобы загрузить приложение.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Установите приложение SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Нажмите на кнопку <span class="text-active-blue">’подключиться’</span> в приложении</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Нажмите на кнопку <span class='text-active-blue'>’подключиться’</span> в приложении</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Отсканируйте QR-код с помощью приложения SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы —<br> они содержатся в хеш-фрагменте URL-адреса ссылки.
+                            Публичные ключи и адрес очереди сообщений, указанные в этой ссылке, НЕ отправляются по сети при просмотре этой страницы &mdash;<br> они содержатся в хеш-фрагменте URL-адреса ссылки.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Установка SimpleX Chat в терминале</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">репозитории GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Если Вы уже установили SimpleX Chat для терминала</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Подпишитесь на нашу рассылку новостей</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введите Ваш адрес Email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Скачать SimpleX <a href="/downloads/#desktop-app">для компьютера</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ru/messaging.md b/ru/messaging.md
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--- /dev/null
+++ b/ru/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Почему SimpleX уникален
+
+### У Вас есть полная конфиденциальность
+
+SimpleX защищает конфиденциальность Вашего профиля, контактов и метаданных, скрывая их от серверов сети SimpleX и любых наблюдателей.
+
+В отличие от любой другой существующей сети обмена сообщениями, SimpleX не имеет идентификаторов пользователей — **нет даже случайных цифр**.
+
+### Вы защищены от спама и злоупотреблений
+
+Поскольку у Вас нет идентификатора или фиксированного адреса в сети SimpleX, никто не сможет связаться с Вами без Вашего явного согласия mdash; это возможно, только если Вы сами поделитесь адресом в виде QR-кода или ссылки.
+
+### Только Вы контролируете Ваши данные
+
+SimpleX хранит все пользовательские данные на клиентских устройствах в **портативном формате зашифрованной базы данных** — их можно перенести на другое устройство.
+
+Сквозные зашифрованные сообщения временно хранятся на серверах SimpleX до получения, после чего они удаляются безвозвратно.
+
+### Вы владеете сетью SimpleX
+
+Сеть SimpleX полностью децентрализована и независима от любой криптовалюты/блокчейна или любой другой сети, кроме Интернета.
+
+Вы можете **использовать SimpleX со своими собственными серверами** или с серверами, предоставленными нами — и при этом подключаться к любому пользователю SimpleX.
+
+# Полная конфиденциальность Вашей личности, профиля, контактов и метаданных
+
+В отличие от других сетей обмена сообщениями, SimpleX **не имеет идентификаторов, присвоенных пользователям**. Он не полагается на номера телефонов, доменные адреса (например, электронную почту или XMPP), имена пользователей, публичные ключи или даже случайные числа для идентификации своих пользователей — операторы серверов SimpleX не знают, сколько людей пользуются их серверами.
+
+Для доставки сообщений SimpleX использует [попарные, анонимные адреса](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) однонаправленных очередей сообщений, раздельные для полученных и отправленных сообщений, обычно через разные серверы.
+
+Этот дизайн защищает конфиденциальность Ваших контактов, скрывая их от серверов SimpleX и от любых внешних наблюдателей. Чтобы скрыть свой IP-адрес от серверов, Вы можете **подключиться к серверам SimpleX через сеть Tor**.
+
+# Лучшая защита от спама и злоупотреблений
+
+Поскольку у Вас нет идентификатора в сети SimpleX, никто не сможет связаться с Вами, если Вы сами не предоставите одноразовый или временный адрес в виде QR-кода или ссылки.
+
+Хоть злоумышленники и могут использовать постоянный адрес для отправки нежелательных запросов или спама, Вы можете легко его изменить или просто удалить, не теряя связи с уже установленными контактами.
+
+# Контроль и безопасность Ваших данных
+
+SimpleX Chat хранит все пользовательские данные на клиентских устройствах в **портативном формате зашифрованной базы данных** которую можно перенести на другое устройство.
+
+Сквозные зашифрованные сообщения временно хранятся на серверах SimpleX до получения, после чего они удаляются безвозвратно.
+
+В отличие от серверов федеративных сетей (электронной почты, XMPP или Matrix), серверы SimpleX не хранят учетные записи пользователей, они только ретранслируют сообщения, защищая конфиденциальность обеих сторон.
+
+Со стороны не видно разницы между отправлением или получением сообщений — если кто-то наблюдает за этим, он не cможет легко определить, кто с кем общается, даже если протокол TLS будет скомпрометирован.
+
+# Полностью децентрализованная — пользователи владеют сетью SimpleX
+
+Вы можете **использовать SimpleX со своими собственными серверами** или с серверами предустановленными в приложении, при этом имея возможность общаться с любым пользователем.
+
+Сеть SimpleX использует [открытый протокол](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) и предоставляет [SDK для создания чат-ботов](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), позволяя внедрять сервисы, с которыми пользователи могут взаимодействовать через приложение SimpleX Chat — мы с нетерпением ждем сервисы SimpleX, которые Вы создадите.
+
+Если Вы рассматриваете возможность разработки для сети SimpleX, например, чат-бота для пользователей SimpleX или интеграции библиотеки SimpleX Chat в Ваше мобильное приложение, пожалуйста, [обращайтесь](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) за любыми советами и поддержкой.
+
+## Функции
+
+Сообщения с E2E-шифрованием
+с форматированием и редактированием
+
+Изображения, видео и файлы
+с E2E-шифрованием
+
+Децентрализованные группы — известные только участникам
+
+Голосовые сообщения с E2E-шифрованием
+
+Исчезающие сообщения
+
+Аудио и видео звонки с E2E-шифрованием
+
+Зашифрованное база данных — Вы можете перенести профиль на другое устройство
+
+Режим инкогнито —
+уникальный для SimpleX Chat
+
+## Что делает SimpleX конфиденциальным
+
+### Временные анонимные парные идентификаторы
+
+SimpleX использует временные анонимные парные адреса и учетные данные для каждого контакта пользователя или члена группы.
+
+Это позволяет доставлять сообщения без идентификаторов профиля пользователя, и обеспечивает лучшую конфиденциальность метаданных, чем альтернативы.
+
+### Обмен ключами вне протокола
+
+Многие коммуникационные сети уязвимы для MITM-атак со стороны серверов или сетевых провайдеров.
+
+Чтобы предотвратить это, приложения SimpleX передают одноразовые ключи вне протокола, когда Вы делитесь адресом в виде ссылки или QR-кода.
+
+### 2-уровневое сквозное шифрование
+
+Протокол двойного обновления ключей —
+"отрицаемые" сообщения с идеальной прямой секретностью и восстановлением после взлома.
+
+NaCL cryptobox в каждой очереди для предотвращения корреляции трафика между очередями сообщений, в случае компрометированного TLS.
+
+### Проверка неизменности сообщений
+
+Для обеспечения неизменности, сообщения нумеруются по порядку и содержат хеш предыдущего сообщения.
+
+Если какое-либо сообщение будет добавлено, удалено или изменено, получатель будет предупрежден об этом.
+
+### Дополнительный уровень шифрования с сервером
+
+Дополнительный уровень шифрования между сервером и получателем для предотвращения корреляции полученного и отправленного трафика сервера, в случае компрометированного TLS.
+
+### Смешивание сообщений для уменьшения корреляции
+
+Серверы SimpleX действуют как узлы-миксеры с низкой задержкой — входящие и исходящие сообщения имеют разный порядок.
+
+### Безопасное аутентифицированное соединение TLS
+
+Для соединений клиента и сервера используется только протокол TLS 1.2/1.3 с безопасными алгоритмами.
+
+Идентификатор сервера и привязка к TLS сессии предотвращают атаки перехвата (MITM) и повторного использования.
+
+Возобновление соединения отключено для предотвращения сеансовых атак.
+
+### Возможен доступ через сеть Tor
+
+Чтобы защитить свой IP-адрес Вы можете подключаться к серверам через сеть Tor или какую-либо другую транспортную оверлейную сеть.
+
+Чтобы использовать SimpleX через сеть Tor, пожалуйста, установите [приложение Orbot](https://guardianproject.info/apps/org.torproject.android/) и включите прокси (или режим VPN [на iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Однонаправленные очереди сообщений
+
+Каждая очередь сообщений передает сообщения в одном направлении с разными адресами отправки и получения.
+
+Это уменьшает векторы атак и доступные метаданные, по сравнению с традиционными серверами доставки сообщений.
+
+### Многоуровневое дополнение сообщений
+
+SimpleX использует дополнение содержания для каждого уровня шифрования, чтобы скрыть размер сообщений.
+
+Это делает сообщениям разного размера одинаковыми для серверов и сети.
+
+## Сеть SimpleX
+
+SimpleX Chat обеспечивает наилучшую конфиденциальность, сочетая преимущества P2P и федеративных сетей.
+
+### В отличие от P2P-сетей
+
+Все сообщения отправляются через серверы, что обеспечивает лучшую конфиденциальность метаданных и надежную асинхронную доставку сообщений, избегая при этом многих .
+
+# Сравнение с протоколами обмена сообщениями P2P
+
+Протоколы и приложения для обмена сообщениями [P2P](https://ru.wikipedia.org/wiki/%D0%9E%D0%B4%D0%BD%D0%BE%D1%80%D0%B0%D0%BD%D0%B3%D0%BE%D0%B2%D0%B0%D1%8F_%D1%81%D0%B5%D1%82%D1%8C) имеют различные проблемы, которые делают их менее надежными, чем SimpleX, более сложными для анализа и уязвимыми для нескольких типов атак.
+
+1. Сети P2P используют [DHT](https://ru.wikipedia.org/wiki/%D0%A0%D0%B0%D1%81%D0%BF%D1%80%D0%B5%D0%B4%D0%B5%D0%BB%D1%91%D0%BD%D0%BD%D0%B0%D1%8F_%D1%85%D0%B5%D1%88-%D1%82%D0%B0%D0%B1%D0%BB%D0%B8%D1%86%D0%B0) (распределенные хеш-таблицы) для маршрутизации сообщений. DHT должны обеспечивать баланс между гарантией доставки и задержкой. SimpleX имеет как лучшую гарантию доставки, так и меньшую задержку, чем P2P. В сетях P2P сообщение передается через нескольких узлов, последовательно, кол-во узлов-посредников будет расти параллельно размеру сети — *O(log N)*.
+2. В отличие от многих P2P сетей, SimpleX спроектирован так, чтобы не нуждаться в глобальных идентификаторах пользователей, даже временных, используя только временные попарные идентификаторы, обеспечивая лучшую анонимность и защиту метаданных пользователей.
+3. P2P не решает проблему [MITM-атаки (Атака посредника)](https://ru.wikipedia.org/wiki/%D0%90%D1%82%D0%B0%D0%BA%D0%B0_%D0%BF%D0%BE%D1%81%D1%80%D0%B5%D0%B4%D0%BD%D0%B8%D0%BA%D0%B0), и многие сети не используют сообщения вне протокола для первоначального обмена ключами. SimpleX использует сообщения вне протокола или, в некоторых случаях, ранее существовавшие защищенные и доверенные соединения для первоначального обмена ключами.
+4. Реализации P2P могут быть заблокированы некоторыми интернет-провайдерами (например, [BitTorrent](https://ru.wikipedia.org/wiki/BitTorrent)). SimpleX протокол не зависит от транспорта — он может быть реализован через стандартные веб-протоколы, например WebSockets.
+5. Все известные P2P-сети могут быть уязвимы для [Атаки Сивиллы](https://ru.wikipedia.org/wiki/%D0%90%D1%82%D0%B0%D0%BA%D0%B0_%D0%A1%D0%B8%D0%B2%D0%B8%D0%BB%D0%BB%D1%8B), поскольку каждый узел доступен для обнаружения, и сеть работает как единое целое. Известные меры по уменьшению риска требуют либо централизованного компонента, либо дорогостоящего [Proof-of-work](https://ru.wikipedia.org/wiki/%D0%94%D0%BE%D0%BA%D0%B0%D0%B7%D0%B0%D1%82%D0%B5%D0%BB%D1%8C%D1%81%D1%82%D0%B2%D0%BE_%D0%B2%D1%8B%D0%BF%D0%BE%D0%BB%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F_%D1%80%D0%B0%D0%B1%D0%BE%D1%82%D1%8B). Сеть SimpleX не позволяет обнаруживать серверы, она фрагментирована и работает как множество изолированных подсетей, из-за чего провести атаку на всю сеть невозможно.
+6. P2P сети могут быть уязвимы для [DRDoS атаки](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), когда клиенты могут ретранслировать и увеличивать трафик, что приводит к отказу всей сети. Клиенты SimpleX ретранслируют трафик только из известных соединений и не могут быть использованы злоумышленником для усиления трафика во всей сети.
+
+---
+
+### В отличие от федеративных сетей
+
+Серверные узлы SimpleX НЕ хранят профили пользователей, контакты и доставленные сообщения, НЕ подключаются друг к другу, и НЕ имеют каталога серверов.
+
+---
+
+### Сеть SimpleX
+
+серверы предоставляют однонаправленные очереди для подключения пользователей, но у них нет видимости графика сетевых подключений — это делают только пользователи.
+
+## Как SimpleX работает
+
+1. Что видят пользователи
+
+2. Как это работает
+
+3. Что видят серверы
+
+1. Что видят пользователи
+
+Вы можете создавать контакты и группы, а также вести двусторонние беседы, как и в любом другом мессенджере.
+
+Как это может работать с однонаправленными очередями и без идентификаторов профиля пользователя?
+
+2. Как это работает
+
+Для каждого контакта Вы используете две отдельные очереди сообщений, отправляя и получая сообщения через разные серверы.
+
+Серверы передают сообщения только в одну сторону, не имея полной информации о разговорах и контактах пользователя.
+
+3. Что видят серверы
+
+Серверы имеют отдельные, анонимные учётные данные для каждой очереди и не знают, каким пользователям они принадлежат.
+
+Пользователи могут дополнительно повысить конфиденциальность метаданных, используя Tor для подключения к серверам. Это предотвращает сопоставление действий по IP-адресу.
+
+## Сравнение с другими протоколами
+
+|  |  | Signal, большие платформы | XMPP, Matrix | Протоколы P2P |
+| --- | --- | --- | --- | --- |
+| Требуется глобальный идентификатор | Нет - конфиденциальный | Да [1] | Да [2] | Да [3] |
+| Возможность MITM | Нет - безопасный [4] | Да [5] | Да | Да |
+| Зависимость от DNS | Нет - устойчив | Да | Да | Нет |
+| Единая или Централизованная сеть | Нет - децентрализованный | Да | Нет - федеративные [6] | Да [7] |
+| Центральный компонент или атака на всю сеть | Нет - устойчив | Да | Да [2] | Да [8] |
+
+---
+
+1. Обычно требуется номера телефона, в некоторых случаях — имя пользователя
+2. Адреса на основе DNS
+3. Публичный ключ или какой-либо другой глобально уникальный идентификатор
+4. Сервера SimpleX не могут скомпрометировать сквозное шифрование
+5. Если операторы серверов скомпрометированы. В Signal, и некоторых других приложениях, есть возможность подтвердить код безопасности
+6. Не защищает конфиденциальность пользовательских метаданных
+7. Хотя P2P распределены, они не являются федеративными, то есть P2P — работают как единая сеть
+8. Сети P2P либо имеют центральный компонент, либо вся сеть может быть атакована — [подробнее здесь](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Сравнение безопасности сквозного шифрования в мессенджерах
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Дополнение сообщений | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Отрицаемые сообщения | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Прямая секретность | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Безопасность после взлома | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-факторный обмен ключами | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Гибридное постквантовое шифрование | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar дополняет сообщения до размера кратного 1024 байтов, Signal - до кратного 160 байтов.
+2. Отрицаемость сообщений не включает в себя соединеие между клиентом и сервером.
+3. По всей видимости, использование криптографической подписи исключает отражаемость, но это требует уточнения.
+4. Реализация поддержки нескольких устройств подрывает безопасность после взлома алгоритма Double Ratchet. — [подробнее здесь](https://eprint.iacr.org/2021/626.pdf).
+5. 2-факторный обмен ключами опциональный, через верификацию кода безопасности.
+6. Пост-квантовое согласование ключей происходит не всегда, защищая только часть согласований.
diff --git a/ru/messaging/index.html b/ru/messaging/index.html
index 94d8bf953b..c78b4325d0 100644
--- a/ru/messaging/index.html
+++ b/ru/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">У Вас есть полная<br>конфиденциальность</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вы защищены от<br>спама и злоупотреблений</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Только Вы контролируете<br>Ваши данные</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вы владеете<br>сетью SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Это позволяет доставлять сообщения без идентификаторов профиля пользователя, и обеспечивает лучшую конфиденциальность метаданных, чем альтернативы.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Чтобы предотвратить это, приложения SimpleX передают одноразовые ключи вне протокола, когда Вы делитесь адресом в виде ссылки или QR-кода.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox в каждой очереди для предотвращения корреляции трафика между очередями сообщений, в случае компрометированного TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Если какое-либо сообщение будет добавлено, удалено или изменено, получатель будет предупрежден об этом.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Дополнительный уровень шифрования между сервером и получателем для предотвращения корреляции полученного и отправленного трафика сервера, в случае компрометированного TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Серверы SimpleX действуют как узлы-миксеры с низкой задержкой — входящие и исходящие сообщения имеют разный порядок.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Возобновление соединения отключено для предотвращения сеансовых атак.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Чтобы использовать SimpleX через сеть Tor, пожалуйста, установите <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">приложение Orbot</a> и включите прокси (или режим VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">на iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Это уменьшает векторы атак и доступные метаданные, по сравнению с традиционными серверами доставки сообщений.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Это делает сообщениям разного размера одинаковыми для серверов и сети.</p>
                             
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@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
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diff --git a/ru/old/index.html b/ru/old/index.html
index cd2e1868e1..7b067fde80 100644
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@@ -60,6 +60,10 @@
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         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
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+<link rel="describedby" href="/llms.txt"/>
+
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         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
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-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
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+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
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                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">Более конфиденциальный</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
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             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -749,10 +754,10 @@ window.addEventListener('click',(e)=>{
     Многие спрашивают: <em>Если у SimpleX нет никаких идентификаторов пользователя, то как приложение знает, куда доставлять сообщения?</em>
 </p>
 <p>
-    Для доставки сообщений вместо идентификаторов пользователей, используемых другими сетями, SimpleX использует временные, анонимные, парные идентификаторы очередей сообщений, отдельные для каждого Вашего контакта — без долгосрочных идентификаторов.
+    Для доставки сообщений вместо идентификаторов пользователей, используемых другими сетями, SimpleX использует временные, анонимные, парные идентификаторы очередей сообщений, отдельные для каждого Вашего контакта &mdash; без долгосрочных идентификаторов.
 </p>
 <p>
-    Вы определяете, какие серверы использовать для получения сообщений, а Ваши контакты — серверы, которые Вы используете для отправки им сообщений. Каждый новый чат, скорее всего, будет вестись на двух разных серверах.
+    Вы определяете, какие серверы использовать для получения сообщений, а Ваши контакты &mdash; серверы, которые Вы используете для отправки им сообщений. Каждый новый чат, скорее всего, будет вестись на двух разных серверах.
 </p>
 <p>
     Этот подход предотвращает утечку любых пользовательских метаданных на уровне приложения. Для дальнейшего улучшения конфиденциальности и защиты Вашего IP-адреса Вы можете подключиться к серверам обмена сообщениями через сеть Tor.
@@ -761,7 +766,7 @@ window.addEventListener('click',(e)=>{
     Только клиентские устройства хранят профили пользователей, контакты и группы; сообщения отправляются с двухуровневым сквозным шифрованием.
 </p>
 <p>
-    Подробнее читайте в <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">техническом описании SimpleX</a>.
+    Подробнее читайте в <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>техническом описании SimpleX</a>.
 </p>
                         </div>
                     </div>
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -794,7 +799,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    <a href="https://www.trailofbits.com/about/">Trail of Bits</a> — ведущая консалтинговая компания в области безопасности, клиентами которой являются крупные технологические компании, правительственные агентства и крупные блокчейн проекты.
+    <a href="https://www.trailofbits.com/about/">Trail of Bits</a> &mdash; ведущая консалтинговая компания в области безопасности, клиентами которой являются крупные технологические компании, правительственные агентства и крупные блокчейн проекты.
 </p>
 <p>
     В ноябре 2022 года Trail of Bits провела аудит криптографии и сетевых компонентов SimpleX. <a href="/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html">Дополнительная информация</a>.
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">Скачать SimpleX <a href="/downloads/#desktop-app">для компьютера</a></p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -931,8 +936,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Почему конфиденциальность <span class="gradient-text">важна</span></h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Сохранение конфиденциальности Ваших метаданных — <span class="text-active-blue">с кем Вы общаетесь</span> — защищает Вас от:</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Почему конфиденциальность <span class='gradient-text'>важна</span></h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Сохранение конфиденциальности Ваших метаданных &mdash; <span class='text-active-blue'>с кем Вы общаетесь</span> &mdash; защищает Вас от:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     Интернет-магазины знают, что люди с более низкими доходами с большей вероятностью совершают срочные покупки, поэтому они могут устанавливать более высокие цены или отменять скидки.
 </p>
 <p>
-    Некоторые финансовые и страховые компании используют социальные сети для определения процентных ставок и премий. Это часто заставляет людей с более низкими доходами платить больше — это известно как <a href="https://fairbydesign.com/povertypremium/" target="_blank">"наценка за бедность"</a>.
+    Некоторые финансовые и страховые компании используют социальные сети для определения процентных ставок и премий. Это часто заставляет людей с более низкими доходами платить больше &mdash; это известно как <a href='https://fairbydesign.com/povertypremium/' target='_blank'>"наценка за бедность"</a>.
 </p>
 <p>
     Сеть SimpleX обеспечивает более высокий уровень конфиденциальности ваших связей, чем любое другое решение, полностью предотвращая доступ компаний и организаций к вашему социальному графу. Даже если пользователи используют серверы, предварительно настроенные в приложениях SimpleX Chat, операторы этих серверов не знают ни количества пользователей, ни их связей.
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1001,13 +1006,13 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Не так давно мы наблюдали, как <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">авторитетная консалтинговая компания</a> манипулировала крупными выборами, используя наши контакты в социальных сетях, чтобы изменять наши мнения и манипулировать нашими голосами.
+    Не так давно мы наблюдали, как <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>авторитетная консалтинговая компания</a> манипулировала крупными выборами, используя наши контакты в социальных сетях, чтобы изменять наши мнения и манипулировать нашими голосами.
 </p>
 <p>
     Чтобы быть объективным и принимать независимые решения, необходимо контролировать своё информационное пространство. Это возможно только, если Вы используете конфиденциальную коммуникационную сеть, которая не имеет доступа к контактам Вашей социальной сети.
 </p>
 <p>
-    SimpleX — это первая сеть, которая не имеет никаких идентификаторов пользователей, таким образом защищая Ваши контакты лучше, чем любая известная альтернатива.
+    SimpleX &mdash; это первая сеть, которая не имеет никаких идентификаторов пользователей, таким образом защищая Ваши контакты лучше, чем любая известная альтернатива.
 </p>
 
                         </div>
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
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         </div>
     </div>
@@ -1045,16 +1050,16 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Каждый должен заботиться о конфиденциальности и безопасности своих коммуникаций — безобидные разговоры могут подвергнуть Вас опасности, например за Ваши политические взгляды, даже если кажется, что Вам "нечего скрывать".
+    Каждый должен заботиться о конфиденциальности и безопасности своих коммуникаций &mdash; безобидные разговоры могут подвергнуть Вас опасности, например за Ваши политические взгляды, даже если кажется, что Вам "нечего скрывать".
 </p>
 <p>
-    Одна из самых шокирующих историй — это опыт <a href="https://ru.wikipedia.org/wiki/Слахи,_Мохаммед_Ульд" target="_blank">Слахи, Мохаммеда Ульда</a>, описанный в его мемуарах и показанный в фильме <a href="https://ru.wikipedia.org/wiki/Мавританец" target="_blank">Мавританец</a>. Он был помещен в лагерь Гуантанамо без суда и следствия и подвергался там пыткам в течение 15 лет после телефонного звонка своему родственнику в Афганистане, из-за подозрения в причастности к терактам 11 сентября, хотя предыдущие 10 лет он жил в Германии.
+    Одна из самых шокирующих историй &mdash; это опыт <a href='https://ru.wikipedia.org/wiki/Слахи,_Мохаммед_Ульд' target='_blank'>Слахи, Мохаммеда Ульда</a>, описанный в его мемуарах и показанный в фильме <a href='https://ru.wikipedia.org/wiki/Мавританец' target='_blank'>Мавританец</a>. Он был помещен в лагерь Гуантанамо без суда и следствия и подвергался там пыткам в течение 15 лет после телефонного звонка своему родственнику в Афганистане, из-за подозрения в причастности к терактам 11 сентября, хотя предыдущие 10 лет он жил в Германии.
 </p>
 <p>
-    Обычных людей арестовывают за то, чем они делятся в Интернете, даже через свои "анонимные" аккаунты, <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html" target="_blank">даже в демократических странах</a>.
+    Обычных людей арестовывают за то, чем они делятся в Интернете, даже через свои "анонимные" аккаунты, <a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html' target='_blank'>даже в демократических странах</a>.
 </p>
 <p>
-    Недостаточно просто использовать мессенджер со сквозным шифрованием, мы все должны использовать мессенджеры, которые защищают конфиденциальность наших личных сетей — с какими людьми мы связаны.
+    Недостаточно просто использовать мессенджер со сквозным шифрованием, мы все должны использовать мессенджеры, которые защищают конфиденциальность наших личных сетей &mdash; с какими людьми мы связаны.
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1083,7 +1088,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Почему SimpleX <span class="gradient-text">уникален</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Почему SimpleX <span class='gradient-text'>уникален</span></h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">У Вас есть полная<br>конфиденциальность</h3>
                             </div>
 
@@ -1109,7 +1114,7 @@ window.addEventListener('click',(e)=>{
     SimpleX защищает конфиденциальность Вашего профиля, контактов и метаданных, скрывая их от серверов сети SimpleX и любых наблюдателей.
 </p>
 <p>
-    В отличие от любой другой существующей сети обмена сообщениями, SimpleX не имеет идентификаторов пользователей — <strong>нет даже случайных цифр</strong>.
+    В отличие от любой другой существующей сети обмена сообщениями, SimpleX не имеет идентификаторов пользователей &mdash; <strong>нет даже случайных цифр</strong>.
 </p>
 
                                     </div>
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Дополнительная информации</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Скрыть информацию</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вы защищены от<br>спама и злоупотреблений</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Дополнительная информации</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Скрыть информацию</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Только Вы контролируете<br>Ваши данные</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleX хранит все пользовательские данные на клиентских устройствах в <strong>портативном формате зашифрованной базы данных</strong> — их можно перенести на другое устройство.
+    SimpleX хранит все пользовательские данные на клиентских устройствах в <strong>портативном формате зашифрованной базы данных</strong> &mdash; их можно перенести на другое устройство.
 </p>
 <p>
     Сквозные зашифрованные сообщения временно хранятся на серверах SimpleX до получения, после чего они удаляются безвозвратно.
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Дополнительная информации</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Скрыть информацию</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вы владеете<br>сетью SimpleX</h3>
                             </div>
 
@@ -1259,7 +1264,7 @@ window.addEventListener('click',(e)=>{
     Сеть SimpleX полностью децентрализована и независима от любой криптовалюты/блокчейна или любой другой сети, кроме Интернета.
 </p>
 <p>
-    Вы можете <strong>использовать SimpleX со своими собственными серверами</strong> или с серверами, предоставленными нами — и при этом подключаться к любому пользователю SimpleX.
+    Вы можете <strong>использовать SimpleX со своими собственными серверами</strong> или с серверами, предоставленными нами &mdash; и при этом подключаться к любому пользователю SimpleX.
 </p>
 
                                     </div>
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Дополнительная информации</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Скрыть информацию</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1320,10 +1325,10 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    В отличие от других сетей обмена сообщениями, SimpleX <strong>не имеет идентификаторов, присвоенных пользователям</strong>. Он не полагается на номера телефонов, доменные адреса (например, электронную почту или XMPP), имена пользователей, публичные ключи или даже случайные числа для идентификации своих пользователей — операторы серверов SimpleX не знают, сколько людей пользуются их серверами.
+    В отличие от других сетей обмена сообщениями, SimpleX <strong>не имеет идентификаторов, присвоенных пользователям</strong>. Он не полагается на номера телефонов, доменные адреса (например, электронную почту или XMPP), имена пользователей, публичные ключи или даже случайные числа для идентификации своих пользователей &mdash; операторы серверов SimpleX не знают, сколько людей пользуются их серверами.
 </p>
 <p>
-    Для доставки сообщений SimpleX использует <a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">попарные, анонимные адреса</a> однонаправленных очередей сообщений, раздельные для полученных и отправленных сообщений, обычно через разные серверы.
+    Для доставки сообщений SimpleX использует <a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>попарные, анонимные адреса</a> однонаправленных очередей сообщений, раздельные для полученных и отправленных сообщений, обычно через разные серверы.
 </p>
 <p>
     Этот дизайн защищает конфиденциальность Ваших контактов, скрывая их от серверов SimpleX и от любых внешних наблюдателей. Чтобы скрыть свой IP-адрес от серверов, Вы можете <strong>подключиться к серверам SimpleX через сеть Tor</strong>.
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     В отличие от серверов федеративных сетей (электронной почты, XMPP или Matrix), серверы SimpleX не хранят учетные записи пользователей, они только ретранслируют сообщения, защищая конфиденциальность обеих сторон.
 </p>
 <p>
-    Со стороны не видно разницы между отправлением или получением сообщений — если кто-то наблюдает за этим, он не cможет легко определить, кто с кем общается, даже если протокол TLS будет скомпрометирован.
+    Со стороны не видно разницы между отправлением или получением сообщений &mdash; если кто-то наблюдает за этим, он не cможет легко определить, кто с кем общается, даже если протокол TLS будет скомпрометирован.
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Полностью децентрализованная — пользователи владеют сетью SimpleX</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Полностью децентрализованная &mdash; пользователи владеют сетью SimpleX</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     Вы можете <strong>использовать SimpleX со своими собственными серверами</strong> или с серверами предустановленными в приложении, при этом имея возможность общаться с любым пользователем.
 </p>
 <p>
-    Сеть SimpleX использует <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">открытый протокол</a> и предоставляет <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK для создания чат-ботов</a>, позволяя внедрять сервисы, с которыми пользователи могут взаимодействовать через приложение SimpleX Chat — мы с нетерпением ждем сервисы SimpleX, которые Вы создадите.
+    Сеть SimpleX использует <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">открытый протокол</a> и предоставляет <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK для создания чат-ботов</a>, позволяя внедрять сервисы, с которыми пользователи могут взаимодействовать через приложение SimpleX Chat &mdash; мы с нетерпением ждем сервисы SimpleX, которые Вы создадите.
 </p>
 <p>
-    Если Вы рассматриваете возможность разработки для сети SimpleX, например, чат-бота для пользователей SimpleX или интеграции библиотеки SimpleX Chat в Ваше мобильное приложение, пожалуйста, <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">обращайтесь</a> за любыми советами и поддержкой.
+    Если Вы рассматриваете возможность разработки для сети SimpleX, например, чат-бота для пользователей SimpleX или интеграции библиотеки SimpleX Chat в Ваше мобильное приложение, пожалуйста, <a href='https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>обращайтесь</a> за любыми советами и поддержкой.
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Сообщения с E2E-шифрованием<br>с форматированием и редактированием</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Изображения, видео и файлы<br>с E2E-шифрованием</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Децентрализованные группы — известные только участникам</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Децентрализованные группы &mdash; известные только участникам</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Голосовые сообщения с E2E-шифрованием</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Исчезающие сообщения</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Аудио и видео звонки с E2E-шифрованием</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Зашифрованное база данных — Вы можете перенести профиль на другое устройство</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Зашифрованное база данных &mdash; Вы можете перенести профиль на другое устройство</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Режим инкогнито —<br>уникальный для SimpleX Chat</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Режим инкогнито &mdash;<br>уникальный для SimpleX Chat</p>
             </div>
             
         </div>
@@ -1570,7 +1575,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Что делает SimpleX <span class="gradient-text">конфиденциальным</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Что делает SimpleX <span class='gradient-text'>конфиденциальным</span></h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Временные анонимные парные идентификаторы</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Обмен ключами<br>вне протокола</h3>
@@ -1614,14 +1619,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">2-уровневое<br>сквозное шифрование</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">Протокол двойного обновления ключей —<br>"отрицаемые" сообщения с идеальной прямой секретностью и восстановлением после взлома.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Протокол двойного обновления ключей &mdash;<br>"отрицаемые" сообщения с идеальной прямой секретностью и восстановлением после взлома.</p>
                             
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL cryptobox в каждой очереди для предотвращения корреляции трафика между очередями сообщений, в случае компрометированного TLS.</p>
                             
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Проверка неизменности<br>сообщений</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Дополнительный уровень<br>шифрования с сервером</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Смешивание сообщений<br>для уменьшения корреляции</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">Серверы SimpleX действуют как узлы-миксеры с низкой задержкой — входящие и исходящие сообщения имеют разный порядок.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Серверы SimpleX действуют как узлы-миксеры с низкой задержкой &mdash; входящие и исходящие сообщения имеют разный порядок.</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">Нажмите, чтобы закрыть</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Безопасное аутентифицированное<br>соединение TLS</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Возможен доступ<br>через сеть Tor</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Однонаправленные<br>очереди сообщений</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Многоуровневое<br>дополнение сообщений</h3>
@@ -1774,14 +1779,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5"><span class="gradient-text">Сеть</span> SimpleX</h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5"><span class='gradient-text'>Сеть</span> SimpleX</h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">SimpleX Chat обеспечивает наилучшую конфиденциальность, сочетая преимущества P2P и федеративных сетей.</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">В отличие от P2P-сетей</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         Все сообщения отправляются через серверы, что обеспечивает лучшую конфиденциальность метаданных и надежную асинхронную доставку сообщений, избегая при этом многих <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">проблем P2P сетей</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">Сравнение с протоколами обмена сообщениями P2P</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1797,23 +1802,23 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Протоколы и приложения для обмена сообщениями <a href="https://ru.wikipedia.org/wiki/Одноранговая_сеть">P2P</a> имеют различные проблемы, которые делают их менее надежными, чем SimpleX, более сложными для анализа и уязвимыми для нескольких типов атак.
+    Протоколы и приложения для обмена сообщениями <a href='https://ru.wikipedia.org/wiki/Одноранговая_сеть'>P2P</a> имеют различные проблемы, которые делают их менее надежными, чем SimpleX, более сложными для анализа и уязвимыми для нескольких типов атак.
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
-        Сети P2P используют <a href="https://ru.wikipedia.org/wiki/Распределённая_хеш-таблица">DHT</a> (распределенные хеш-таблицы) для маршрутизации сообщений. DHT должны обеспечивать баланс между гарантией доставки и задержкой. SimpleX имеет как лучшую гарантию доставки, так и меньшую задержку, чем P2P. В сетях P2P сообщение передается через нескольких узлов, последовательно, кол-во узлов-посредников будет расти параллельно размеру сети — <em>O(log N)</em>.
+        Сети P2P используют <a href='https://ru.wikipedia.org/wiki/Распределённая_хеш-таблица'>DHT</a> (распределенные хеш-таблицы) для маршрутизации сообщений. DHT должны обеспечивать баланс между гарантией доставки и задержкой. SimpleX имеет как лучшую гарантию доставки, так и меньшую задержку, чем P2P. В сетях P2P сообщение передается через нескольких узлов, последовательно, кол-во узлов-посредников будет расти параллельно размеру сети &mdash; <em>O(log N)</em>.
     </li>
     <li>
         В отличие от многих P2P сетей, SimpleX спроектирован так, чтобы не нуждаться в глобальных идентификаторах пользователей, даже временных, используя только временные попарные идентификаторы, обеспечивая лучшую анонимность и защиту метаданных пользователей.
     </li>
     <li>
-        P2P не решает проблему <a href="https://ru.wikipedia.org/wiki/Атака_посредника">MITM-атаки (Атака посредника)</a>, и многие сети не используют сообщения вне протокола для первоначального обмена ключами. SimpleX использует сообщения вне протокола или, в некоторых случаях, ранее существовавшие защищенные и доверенные соединения для первоначального обмена ключами.
+        P2P не решает проблему <a href='https://ru.wikipedia.org/wiki/Атака_посредника'>MITM-атаки (Атака посредника)</a>, и многие сети не используют сообщения вне протокола для первоначального обмена ключами. SimpleX использует сообщения вне протокола или, в некоторых случаях, ранее существовавшие защищенные и доверенные соединения для первоначального обмена ключами.
     </li>
     <li>
-        Реализации P2P могут быть заблокированы некоторыми интернет-провайдерами (например, <a href="https://ru.wikipedia.org/wiki/BitTorrent">BitTorrent</a>). SimpleX протокол не зависит от транспорта — он может быть реализован через стандартные веб-протоколы, например WebSockets.
+        Реализации P2P могут быть заблокированы некоторыми интернет-провайдерами (например, <a href='https://ru.wikipedia.org/wiki/BitTorrent'>BitTorrent</a>). SimpleX протокол не зависит от транспорта &mdash; он может быть реализован через стандартные веб-протоколы, например WebSockets.
     </li>
     <li>
-        Все известные P2P-сети могут быть уязвимы для <a href="https://ru.wikipedia.org/wiki/Атака_Сивиллы">Атаки Сивиллы</a>, поскольку каждый узел доступен для обнаружения, и сеть работает как единое целое. Известные меры по уменьшению риска требуют либо централизованного компонента, либо дорогостоящего <a href="https://ru.wikipedia.org/wiki/Доказательство_выполнения_работы">Proof-of-work</a>. Сеть SimpleX не позволяет обнаруживать серверы, она фрагментирована и работает как множество изолированных подсетей, из-за чего провести атаку на всю сеть невозможно.
+        Все известные P2P-сети могут быть уязвимы для <a href='https://ru.wikipedia.org/wiki/Атака_Сивиллы'>Атаки Сивиллы</a>, поскольку каждый узел доступен для обнаружения, и сеть работает как единое целое. Известные меры по уменьшению риска требуют либо централизованного компонента, либо дорогостоящего <a href='https://ru.wikipedia.org/wiki/Доказательство_выполнения_работы'>Proof-of-work</a>. Сеть SimpleX не позволяет обнаруживать серверы, она фрагментирована и работает как множество изолированных подсетей, из-за чего провести атаку на всю сеть невозможно.
     </li>
     <li>
         P2P сети могут быть уязвимы для <a href="https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent">DRDoS атаки</a>, когда клиенты могут ретранслировать и увеличивать трафик, что приводит к отказу всей сети. Клиенты SimpleX ретранслируют трафик только из известных соединений и не могут быть использованы злоумышленником для усиления трафика во всей сети.
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">В отличие от федеративных сетей</h3>
@@ -1862,13 +1867,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">Сеть SimpleX</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        серверы предоставляют <span class="text-active-blue">однонаправленные очереди</span> для подключения пользователей, но у них нет видимости графика сетевых подключений — это делают только пользователи.
+                        серверы предоставляют <span class='text-active-blue'>однонаправленные очереди</span> для подключения пользователей, но у них нет видимости графика сетевых подключений &mdash; это делают только пользователи.
                     </p>
                 </div>
             </div>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. Что видят пользователи</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Вы можете создавать контакты и группы, а также вести двусторонние беседы, как и в любом другом мессенджере.
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. Как это работает</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Для каждого контакта Вы используете две отдельные очереди сообщений, отправляя и получая сообщения через разные серверы.
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. Что видят серверы</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Серверы имеют отдельные, анонимные учётные данные для каждой очереди и не знают, каким пользователям они принадлежат.
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal, большие платформы</th>
                         <th class="pb-4">XMPP, Matrix</th>
@@ -2111,7 +2116,7 @@ window.addEventListener("load", function () {
                     <li> Сервера SimpleX не могут скомпрометировать сквозное шифрование</li>
                     <li> Если операторы серверов скомпрометированы. В Signal, и некоторых других приложениях, есть возможность подтвердить код безопасности</li>
                     <li> Не защищает конфиденциальность пользовательских метаданных</li>
-                    <li> Хотя P2P распределены, они не являются федеративными, то есть P2P — работают как единая сеть</li>
+                    <li> Хотя P2P распределены, они не являются федеративными, то есть P2P &mdash; работают как единая сеть</li>
                     <li> Сети P2P либо имеют центральный компонент, либо вся сеть может быть атакована - <a class="underline text-primary-light dark:text-primary-dark underline-offset-2" href="https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols">подробнее здесь</a></li>
                 </ol>
             </div>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Подпишитесь на нашу рассылку новостей</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введите Ваш адрес Email">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">Скачать SimpleX <a href="/downloads/#desktop-app">для компьютера</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/ru/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/ru/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/ru/why.md b/ru/why.md
new file mode 100644
index 0000000000..b4180f6bb2
--- /dev/null
+++ b/ru/why.md
@@ -0,0 +1,19 @@
+# Вы родились без аккаунта.
+
+Никто не отслеживал ваши разговоры. Никто не составлял карту ваших перемещений. Конфиденциальность не была функцией — это был образ жизни.
+
+Потом мы вышли в интернет, и каждая платформа попросила частичку вас — ваше имя, ваш номер, ваших друзей. Мы смирились с тем, что за возможность общаться приходится отдавать информацию о том, с кем мы общаемся. Каждое поколение людей и технологий жило так — телефон, электронная почта, мессенджеры, социальные сети. Казалось, что другого пути нет.
+
+Другой путь есть. Сеть без номеров телефонов. Без имён пользователей. Без аккаунтов. Без каких-либо идентификаторов пользователей. Сеть, которая соединяет людей и передаёт зашифрованные сообщения, не зная, кто с кем связан.
+
+Не более надёжный замок на чужой двери. Не более вежливый хозяин, который уважает вашу частную жизнь, но всё равно ведёт учёт всех посетителей. Вы не гость. Вы у себя дома. Ни один король не войдёт в ваш дом — вы суверенны.
+
+Ваши разговоры принадлежат вам, как это всегда было до интернета. Сеть — это не место, куда вы приходите. Это место, которое вы создаёте и которым владеете. И никто не может это у вас отнять, делаете ли вы его конфиденциальным или публичным.
+
+Древнейшая человеческая свобода — говорить с другим человеком без слежки — построенная на инфраструктуре, которая не может её предать.
+
+Потому что мы разрушили саму возможность узнать, кто вы. Чтобы вашу свободу невозможно было отнять.
+
+Будь свободен в своей сети.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/ru/why/index.html b/ru/why/index.html
index c536386518..acd1a16f67 100644
--- a/ru/why/index.html
+++ b/ru/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/ru/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Будь свободен в своей сети.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/security.md b/security.md
new file mode 100644
index 0000000000..093f0b5380
--- /dev/null
+++ b/security.md
@@ -0,0 +1,75 @@
+# Security Policy
+
+While great care is taken to ensure the highest level of security and privacy in SimpleX network servers and clients, all software can have flaws, and we believe it is a critical part of an organization's social responsibility to minimize the impact of these flaws through continual vulnerability discovery efforts, defense in depth design, and prompt remediation and notification.
+
+The implementation security assessment of SimpleX cryptography and networking was done by Trail of Bits in [November 2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+
+The cryptographic review of SimpleX protocols design was done by Trail of Bits in [July 2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md).
+
+We have scheduled implementation security assessment for June 2026.
+
+## Reporting security issues
+
+To report a security issue, please contact us directly via email [chat@simplex.chat](mailto:chat@simplex.chat). Please do NOT report security issues via GitHub issues or via any public channels.
+
+Please encrypt the email message using the key for this address from [keys.openpgp.org](https://keys.openpgp.org/search?q=chat%40simplex.chat) (its fingerprint is `FB44 AF81 A45B DE32 7319 797C 8510 7E35 7D4A 17FC`) and make your key available for a secure reply.
+
+While we encourage you to encrypt the message, if this poses a barrier to reporting, an unencrypted submission is better than no submission.
+
+## Issue triage
+
+Our team will investigate and prioritize the reported issue. We may work in private with individuals who are not our direct team members, as well as other organizations, where we believe this can help with the issue investigation, resolution, or testing.
+
+## Threat Model
+
+Please review threat model for SimpleX: https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#threat-model
+
+Certain threats are considered out of the scope of SimpleX security model. For example, we do not consider SimpleX secure against the following classes of attacks:
+
+- CPU/hardware flaws.
+- physical observation side channels (e.g. power consumption, EM emissions, etc).
+
+Further, any user data stored on the device can be accessed with user's or root privileges, such as:
+- user files in the app storage (encrypted or not, depending on the app settings).
+- encrypted database.
+- database encryption key in case it is stored on the device.
+
+Mitigations for security issues outside of our threat model may still be implemented, however they will be weighed against competing priorities, and we do not classify them as SimpleX vulnerabilities.
+
+## Issue severity
+
+We will determine the risk of each issue, taking into account our experience dealing with past issues, versions affected, common defaults, and use cases. We classify issues on two dimensions, based on their severity level and the difficulty required to exploit them.
+
+**Difficulty levels**
+
+- **Low**: The flaw is well known; public tools for its exploitation exist or can be scripted.
+- **Medium**: An attacker must write an exploit or will need in-depth knowledge of the system.
+- **High**: An attacker must have privileged access to the system, may need to know complex technical details, or must discover other weaknesses to exploit this issue.
+
+**Issue severity levels**
+
+- **CRITICAL severity**. Such issues should affect common configurations and be exploitable with low or medium difficulty. For example: significant disclosure of the encrypted users' messages or files either via relays or via communication channels, vulnerabilities which can be easily exploited remotely to compromise clients or servers private keys. These issues will be kept private and will trigger a new release of all supported versions.
+- **HIGH severity**. This includes issues that are of a lower risk than critical, possibly due to affecting less common configurations, or have high difficulty to be exploited. These issues will be kept private and will trigger a new release of all supported versions.
+- **MEDIUM severity**. This includes issues like crashes in client applications caused by the received messages or files, flaws in protocols that are less commonly used, and local flaws. These will in general be kept private until the next release, and that release will be scheduled so that it can roll up several such flaws at one time.
+- **LOW severity**. This includes issues such as those that only affect the SimpleX CLI app, or unlikely configurations, or issues that would be classified as medium but are very difficult to exploit. These will in general be fixed immediately in latest development versions, and may be back-ported to older versions that are still getting updates. These issues may be kept private or be included in commit messages.
+
+## Notification policy
+
+Security fixes of critical, high and medium severity MUST NOT be mentioned in the commit message. Security fixes of low severity MAY be mentioned in the commit messages.
+
+We will privately notify trusted partners about forthcoming security fixes on the day when the fix is publicly released and available for download via all supported channels, indicating the issue level, but not further details.
+
+7 days after the new software version is released and available for download via all supported channels, we will indicate that it fixes a security issue and its level, but not further details. This notification will be published in our release notes and broadcast channels we use.
+
+14 days later the details will be published in the release notes, describing the impact and the nature of vulnerability, but not necessarily providing detailed instruction for the exploit - it will be decided on a case by case basis.
+
+## Trusted partners
+
+You may be privately notified about the forthcoming releases containing fixes to the security issues of critical, high and medium severity. We will communicate only the level of the issue severity, and not the issue itself.
+
+To be included in this list, you should be one of the following:
+- software or hardware vendor depending on our code.
+- commercial or non-profit organization that uses our software in scenarios where security and privacy is critically important.
+- we may also include other organizations that are not listed but would otherwise qualify for list membership.
+- we may also include organizations with which we have a commercial relationship.
+- we may withdraw notifying certain organizations if they leak issues before they are public or do not add value.
diff --git a/security/index.html b/security/index.html
index 4b553b8fbd..42dc4a1058 100644
--- a/security/index.html
+++ b/security/index.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/security.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/sitemap.xml b/sitemap.xml
new file mode 100644
index 0000000000..9fe7c90805
--- /dev/null
+++ b/sitemap.xml
@@ -0,0 +1,304 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+  <url><loc>https://simplex.chat/</loc></url>
+  <url><loc>https://simplex.chat/about/</loc></url>
+  <url><loc>https://simplex.chat/ar/</loc></url>
+  <url><loc>https://simplex.chat/ar/contact/</loc></url>
+  <url><loc>https://simplex.chat/ar/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/ar/file/</loc></url>
+  <url><loc>https://simplex.chat/ar/invitation/</loc></url>
+  <url><loc>https://simplex.chat/ar/messaging/</loc></url>
+  <url><loc>https://simplex.chat/ar/why/</loc></url>
+  <url><loc>https://simplex.chat/az/</loc></url>
+  <url><loc>https://simplex.chat/az/contact/</loc></url>
+  <url><loc>https://simplex.chat/az/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/az/file/</loc></url>
+  <url><loc>https://simplex.chat/az/invitation/</loc></url>
+  <url><loc>https://simplex.chat/az/messaging/</loc></url>
+  <url><loc>https://simplex.chat/az/why/</loc></url>
+  <url><loc>https://simplex.chat/bg/</loc></url>
+  <url><loc>https://simplex.chat/bg/contact/</loc></url>
+  <url><loc>https://simplex.chat/bg/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/bg/file/</loc></url>
+  <url><loc>https://simplex.chat/bg/invitation/</loc></url>
+  <url><loc>https://simplex.chat/bg/messaging/</loc></url>
+  <url><loc>https://simplex.chat/bg/why/</loc></url>
+  <url><loc>https://simplex.chat/blog/</loc></url>
+  <url><loc>https://simplex.chat/blog/20201022-simplex-chat.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20210512-simplex-chat-terminal-ui.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20210914-simplex-chat-v0.4-released.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20211208-simplex-chat-v0.5-released.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220112-simplex-chat-v1-released.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220214-simplex-chat-ios-public-beta.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220308-simplex-chat-mobile-apps.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220404-simplex-chat-instant-notifications.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220511-simplex-chat-v2-images-files.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220524-simplex-chat-better-privacy.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220604-simplex-chat-new-privacy-security-settings.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220711-simplex-chat-v3-released-ios-notifications-audio-video-calls-database-export-import-protocol-improvements.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220723-simplex-chat-v3.1-tor-groups-efficiency.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220808-simplex-chat-v3.1-chat-groups.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220901-simplex-chat-v3.2-incognito-mode.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20220928-simplex-chat-v4-encrypted-database.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20221206-simplex-chat-v4.3-voice-messages.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230103-simplex-chat-v4.4-disappearing-messages.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230204-simplex-chat-v4-5-user-chat-profiles.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230328-simplex-chat-v4-6-hidden-profiles.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230422-simplex-chat-vision-funding-v5-videos-files-passcode.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230523-simplex-chat-v5-1-message-reactions-self-destruct-passcode.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230722-simplex-chat-v5-2-message-delivery-receipts.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240124-simplex-chat-infrastructure-costs-v5-5-simplex-ux-private-notes-group-history.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240314-simplex-chat-v5-6-quantum-resistance-signal-double-ratchet-algorithm.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240323-simplex-network-privacy-non-profit-v5-6-quantum-resistant-e2e-encryption-simple-migration.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240416-dangers-of-metadata-in-messengers.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240426-simplex-legally-binding-transparency-v5-7-better-user-experience.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240516-simplex-redefining-privacy-hard-choices.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240601-protecting-children-safety-requires-e2e-encryption.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240604-simplex-chat-v5.8-private-message-routing-chat-themes.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240704-future-of-privacy-enforcing-privacy-standards.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20240814-simplex-chat-vision-funding-v6-private-routing-new-user-experience.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20241016-wired-attack-on-privacy.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20241125-servers-operated-by-flux-true-privacy-and-decentralization-for-all-users.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20241210-simplex-network-v6-2-servers-by-flux-business-chats.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20241218-oppose-digital-ids-they-break-law-lead-to-mass-scale-surveillance.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20250114-simplex-network-large-groups-privacy-preserving-content-moderation.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20250703-simplex-network-protocol-extension-for-securely-connecting-people.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20250729-simplex-chat-v6-4-1-welcome-contacts-protect-groups-app-security.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20260430-simplex-channels-v6-5-consortium-crowdfunding-freedom-of-speech.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20260722-simplex-public-names.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20260819-simplex-chat-crowdfunding.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20260908-nick-rogers-why-i-backed-simplex-chat.html</loc></url>
+  <url><loc>https://simplex.chat/blog/20260919-simplex-supporter-badges.html</loc></url>
+  <url><loc>https://simplex.chat/blog/lang/fr-fr/README_fr/</loc></url>
+  <url><loc>https://simplex.chat/call/</loc></url>
+  <url><loc>https://simplex.chat/contact/</loc></url>
+  <url><loc>https://simplex.chat/credits/</loc></url>
+  <url><loc>https://simplex.chat/crowdfunding-news/</loc></url>
+  <url><loc>https://simplex.chat/crowdfunding/</loc></url>
+  <url><loc>https://simplex.chat/cs/</loc></url>
+  <url><loc>https://simplex.chat/cs/contact/</loc></url>
+  <url><loc>https://simplex.chat/cs/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/cs/file/</loc></url>
+  <url><loc>https://simplex.chat/cs/invitation/</loc></url>
+  <url><loc>https://simplex.chat/cs/messaging/</loc></url>
+  <url><loc>https://simplex.chat/cs/why/</loc></url>
+  <url><loc>https://simplex.chat/de/</loc></url>
+  <url><loc>https://simplex.chat/de/contact/</loc></url>
+  <url><loc>https://simplex.chat/de/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/de/file/</loc></url>
+  <url><loc>https://simplex.chat/de/invitation/</loc></url>
+  <url><loc>https://simplex.chat/de/messaging/</loc></url>
+  <url><loc>https://simplex.chat/de/why/</loc></url>
+  <url><loc>https://simplex.chat/directory/</loc></url>
+  <url><loc>https://simplex.chat/docs/android.html</loc></url>
+  <url><loc>https://simplex.chat/docs/business.html</loc></url>
+  <url><loc>https://simplex.chat/docs/chat-relay.html</loc></url>
+  <url><loc>https://simplex.chat/docs/cli.html</loc></url>
+  <url><loc>https://simplex.chat/docs/code_of_conduct.html</loc></url>
+  <url><loc>https://simplex.chat/docs/contributing.html</loc></url>
+  <url><loc>https://simplex.chat/docs/directory.html</loc></url>
+  <url><loc>https://simplex.chat/docs/glossary.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/app-settings.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/audio-video-calls.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/channel-webpage.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/chat-profiles.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/making-connections.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/managing-data.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/privacy-security.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/readme.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/register-simplex-name.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/secret-groups.html</loc></url>
+  <url><loc>https://simplex.chat/docs/guide/send-messages.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/android.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/cli.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/contributing.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/server.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/simplex.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/translations.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/cs/webrtc.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/android.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/cli.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/contributing.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/server.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/simplex.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/translations.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/fr/webrtc.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/android.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/cli.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/contributing.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/server.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/simplex.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/translations.html</loc></url>
+  <url><loc>https://simplex.chat/docs/lang/pl/webrtc.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/badges-overview.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/badges-rpc.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/channels-overview.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/channels-protocol.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/names-overview.html</loc></url>
+  <url><loc>https://simplex.chat/docs/protocol/simplex-chat.html</loc></url>
+  <url><loc>https://simplex.chat/docs/server.html</loc></url>
+  <url><loc>https://simplex.chat/docs/simplex.html</loc></url>
+  <url><loc>https://simplex.chat/docs/themes.html</loc></url>
+  <url><loc>https://simplex.chat/docs/trademark.html</loc></url>
+  <url><loc>https://simplex.chat/docs/translations.html</loc></url>
+  <url><loc>https://simplex.chat/docs/webrtc.html</loc></url>
+  <url><loc>https://simplex.chat/docs/why.html</loc></url>
+  <url><loc>https://simplex.chat/docs/xftp-server.html</loc></url>
+  <url><loc>https://simplex.chat/donate/</loc></url>
+  <url><loc>https://simplex.chat/downloads/</loc></url>
+  <url><loc>https://simplex.chat/en/</loc></url>
+  <url><loc>https://simplex.chat/en/contact/</loc></url>
+  <url><loc>https://simplex.chat/en/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/en/file/</loc></url>
+  <url><loc>https://simplex.chat/en/invitation/</loc></url>
+  <url><loc>https://simplex.chat/en/messaging/</loc></url>
+  <url><loc>https://simplex.chat/en/why/</loc></url>
+  <url><loc>https://simplex.chat/es/</loc></url>
+  <url><loc>https://simplex.chat/es/contact/</loc></url>
+  <url><loc>https://simplex.chat/es/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/es/file/</loc></url>
+  <url><loc>https://simplex.chat/es/invitation/</loc></url>
+  <url><loc>https://simplex.chat/es/messaging/</loc></url>
+  <url><loc>https://simplex.chat/es/why/</loc></url>
+  <url><loc>https://simplex.chat/fa/</loc></url>
+  <url><loc>https://simplex.chat/fa/contact/</loc></url>
+  <url><loc>https://simplex.chat/fa/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/fa/file/</loc></url>
+  <url><loc>https://simplex.chat/fa/invitation/</loc></url>
+  <url><loc>https://simplex.chat/fa/messaging/</loc></url>
+  <url><loc>https://simplex.chat/fa/why/</loc></url>
+  <url><loc>https://simplex.chat/faq/</loc></url>
+  <url><loc>https://simplex.chat/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/fi/</loc></url>
+  <url><loc>https://simplex.chat/fi/contact/</loc></url>
+  <url><loc>https://simplex.chat/fi/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/fi/file/</loc></url>
+  <url><loc>https://simplex.chat/fi/invitation/</loc></url>
+  <url><loc>https://simplex.chat/fi/messaging/</loc></url>
+  <url><loc>https://simplex.chat/fi/why/</loc></url>
+  <url><loc>https://simplex.chat/file/</loc></url>
+  <url><loc>https://simplex.chat/fonts/GT-Walsheim/README/</loc></url>
+  <url><loc>https://simplex.chat/fr/</loc></url>
+  <url><loc>https://simplex.chat/fr/contact/</loc></url>
+  <url><loc>https://simplex.chat/fr/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/fr/file/</loc></url>
+  <url><loc>https://simplex.chat/fr/invitation/</loc></url>
+  <url><loc>https://simplex.chat/fr/messaging/</loc></url>
+  <url><loc>https://simplex.chat/fr/why/</loc></url>
+  <url><loc>https://simplex.chat/he/</loc></url>
+  <url><loc>https://simplex.chat/he/contact/</loc></url>
+  <url><loc>https://simplex.chat/he/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/he/file/</loc></url>
+  <url><loc>https://simplex.chat/he/invitation/</loc></url>
+  <url><loc>https://simplex.chat/he/messaging/</loc></url>
+  <url><loc>https://simplex.chat/he/why/</loc></url>
+  <url><loc>https://simplex.chat/hu/</loc></url>
+  <url><loc>https://simplex.chat/hu/contact/</loc></url>
+  <url><loc>https://simplex.chat/hu/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/hu/file/</loc></url>
+  <url><loc>https://simplex.chat/hu/invitation/</loc></url>
+  <url><loc>https://simplex.chat/hu/messaging/</loc></url>
+  <url><loc>https://simplex.chat/hu/why/</loc></url>
+  <url><loc>https://simplex.chat/id/</loc></url>
+  <url><loc>https://simplex.chat/id/contact/</loc></url>
+  <url><loc>https://simplex.chat/id/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/id/file/</loc></url>
+  <url><loc>https://simplex.chat/id/invitation/</loc></url>
+  <url><loc>https://simplex.chat/id/messaging/</loc></url>
+  <url><loc>https://simplex.chat/id/why/</loc></url>
+  <url><loc>https://simplex.chat/invitation/</loc></url>
+  <url><loc>https://simplex.chat/it/</loc></url>
+  <url><loc>https://simplex.chat/it/contact/</loc></url>
+  <url><loc>https://simplex.chat/it/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/it/file/</loc></url>
+  <url><loc>https://simplex.chat/it/invitation/</loc></url>
+  <url><loc>https://simplex.chat/it/messaging/</loc></url>
+  <url><loc>https://simplex.chat/it/why/</loc></url>
+  <url><loc>https://simplex.chat/ja/</loc></url>
+  <url><loc>https://simplex.chat/ja/contact/</loc></url>
+  <url><loc>https://simplex.chat/ja/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/ja/file/</loc></url>
+  <url><loc>https://simplex.chat/ja/invitation/</loc></url>
+  <url><loc>https://simplex.chat/ja/messaging/</loc></url>
+  <url><loc>https://simplex.chat/ja/why/</loc></url>
+  <url><loc>https://simplex.chat/jobs/</loc></url>
+  <url><loc>https://simplex.chat/links/</loc></url>
+  <url><loc>https://simplex.chat/livestream/</loc></url>
+  <url><loc>https://simplex.chat/messaging/</loc></url>
+  <url><loc>https://simplex.chat/news/</loc></url>
+  <url><loc>https://simplex.chat/nl/</loc></url>
+  <url><loc>https://simplex.chat/nl/contact/</loc></url>
+  <url><loc>https://simplex.chat/nl/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/nl/file/</loc></url>
+  <url><loc>https://simplex.chat/nl/invitation/</loc></url>
+  <url><loc>https://simplex.chat/nl/messaging/</loc></url>
+  <url><loc>https://simplex.chat/nl/why/</loc></url>
+  <url><loc>https://simplex.chat/pl/</loc></url>
+  <url><loc>https://simplex.chat/pl/contact/</loc></url>
+  <url><loc>https://simplex.chat/pl/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/pl/file/</loc></url>
+  <url><loc>https://simplex.chat/pl/invitation/</loc></url>
+  <url><loc>https://simplex.chat/pl/messaging/</loc></url>
+  <url><loc>https://simplex.chat/pl/why/</loc></url>
+  <url><loc>https://simplex.chat/privacy/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/contact/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/file/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/invitation/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/messaging/</loc></url>
+  <url><loc>https://simplex.chat/pt_BR/why/</loc></url>
+  <url><loc>https://simplex.chat/reproduce/</loc></url>
+  <url><loc>https://simplex.chat/ro/</loc></url>
+  <url><loc>https://simplex.chat/ro/contact/</loc></url>
+  <url><loc>https://simplex.chat/ro/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/ro/file/</loc></url>
+  <url><loc>https://simplex.chat/ro/invitation/</loc></url>
+  <url><loc>https://simplex.chat/ro/messaging/</loc></url>
+  <url><loc>https://simplex.chat/ro/why/</loc></url>
+  <url><loc>https://simplex.chat/ru/</loc></url>
+  <url><loc>https://simplex.chat/ru/contact/</loc></url>
+  <url><loc>https://simplex.chat/ru/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/ru/file/</loc></url>
+  <url><loc>https://simplex.chat/ru/invitation/</loc></url>
+  <url><loc>https://simplex.chat/ru/messaging/</loc></url>
+  <url><loc>https://simplex.chat/ru/why/</loc></url>
+  <url><loc>https://simplex.chat/security/</loc></url>
+  <url><loc>https://simplex.chat/tr/</loc></url>
+  <url><loc>https://simplex.chat/tr/contact/</loc></url>
+  <url><loc>https://simplex.chat/tr/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/tr/file/</loc></url>
+  <url><loc>https://simplex.chat/tr/invitation/</loc></url>
+  <url><loc>https://simplex.chat/tr/messaging/</loc></url>
+  <url><loc>https://simplex.chat/tr/why/</loc></url>
+  <url><loc>https://simplex.chat/transparency/</loc></url>
+  <url><loc>https://simplex.chat/uk/</loc></url>
+  <url><loc>https://simplex.chat/uk/contact/</loc></url>
+  <url><loc>https://simplex.chat/uk/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/uk/file/</loc></url>
+  <url><loc>https://simplex.chat/uk/invitation/</loc></url>
+  <url><loc>https://simplex.chat/uk/messaging/</loc></url>
+  <url><loc>https://simplex.chat/uk/why/</loc></url>
+  <url><loc>https://simplex.chat/why/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/contact/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/file/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/invitation/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/messaging/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hans/why/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/contact/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/fdroid/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/file/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/invitation/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/messaging/</loc></url>
+  <url><loc>https://simplex.chat/zh_Hant/why/</loc></url>
+</urlset>
diff --git a/tr/contact.md b/tr/contact.md
new file mode 100644
index 0000000000..f7ed461d5e
--- /dev/null
+++ b/tr/contact.md
@@ -0,0 +1,66 @@
+# SimpleX Chat ile bağlantı kurmak için bir adres aldınız
+
+## Mobil cihazınızda veya tabletinizde SimpleX Chat uygulamasıyla QR kodunu tarayın.
+
+Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ — bağlantı URL'sinin hash bölümünde yer alır.
+
+SimpleX Chat'i henüz indirmediniz mi?
+
+Uygulamayı indirmek için aşağıdaki bağlantıları kullanın.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Mobil uygulamadan QR kodunu tarayın
+
+# SimpleX Chat ile bağlantı kurmak için bir adres aldınız
+
+Bağlantı başlatmak için:
+
+SimpleX uygulamasını yükleyin
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid)
+
+1
+
+Uygulamada bağlanın
+
+SimpleX uygulamasını açın
+
+2
+
+Uygulamada "Bağlan" düğmesine dokunun
+
+3
+
+## SimpleX Chat uygulamasıyla QR kodunu tarayın
+
+Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ —
+bağlantı URL'sinin hash bölümünde yer alır.
+
+## Terminalde SimpleX Chat kurulumu
+
+Bu komutu kullanın:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+SimpleX Chat'i gör GitHub deposu İndirme veya kaynak koddan derleme talimatları için.
+
+---
+
+## SimpleX'i terminal için zaten yüklediyseniz
+
+Zaten yüklediyseniz Terminal için SimpleX Chat v1.0.0+, Aşağıdaki komutu kopyalayıp sohbette kullanın:
+
+## Katılın SimpleX
+
+Sizi sohbete katılmaya davet ediyoruz
+
+[Reddit grubuna katılın](https://www.reddit.com/r/SimpleXChat/) [GitHub'da bize katılın](https://github.com/simplex-chat) [Bize destek olmak için buradan bağış yapın](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Güncellemelerimizi almak için kaydolun
+
+---
+
+SimpleX' [masaüstü uygulamasını](https://simplex.chat/downloads) indirin
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid)
diff --git a/tr/contact/index.html b/tr/contact/index.html
index c4212baa84..e412b9ac7b 100644
--- a/tr/contact/index.html
+++ b/tr/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">SimpleX Chat ile bağlantı kurmak için bir adres aldınız</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Mobil cihazınızda veya tabletinizde SimpleX Chat uygulamasıyla QR kodunu tarayın.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ — bağlantı URL'sinin hash bölümünde yer alır.
+                Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ &mdash; bağlantı URL'sinin hash bölümünde yer alır.
             </p>
             <p class="text-grey-black dark:text-white text-base">SimpleX Chat'i henüz indirmediniz mi?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Uygulamayı indirmek için aşağıdaki bağlantıları kullanın.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">SimpleX uygulamasını yükleyin</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -748,7 +755,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Uygulamada <span class="text-active-blue">"Bağlan"</span> düğmesine dokunun</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Uygulamada <span class='text-active-blue'>"Bağlan"</span> düğmesine dokunun</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX Chat uygulamasıyla QR kodunu tarayın</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ —<br> bağlantı URL'sinin hash bölümünde yer alır.
+                            Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ &mdash;<br> bağlantı URL'sinin hash bölümünde yer alır.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Terminalde SimpleX Chat kurulumu</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub deposu</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX'i terminal için zaten yüklediyseniz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Güncellemelerimizi almak için kaydolun</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="E-posta adresinizi girin">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">SimpleX' <a href="/downloads">masaüstü uygulamasını</a> indirin</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/tr/fdroid.md b/tr/fdroid.md
new file mode 100644
index 0000000000..b20f70458f
--- /dev/null
+++ b/tr/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## F-Droid ile SimpleX Chat
+
+### SimpleX Chat deposu
+
+Geliştiriciler tarafından oluşturulan kararlı ve beta sürümler
+
+F-Droid istemcinize eklemek için QR kodunu tarayın veya bu URL'yi kullanın:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+İmza anahtarı parmak izi (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org deposu
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+F-Droid.org tarafından oluşturulan kararlı sürümler
+
+Bu depoya sürümler birkaç gün sonra eklenir.
+
+SimpleX Chat ve F-Droid.org depoları farklı anahtarlarla imzalanır. Geçiş yapmak için [sohbet veritabanınızı dışa aktarın](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) ve uygulamayı yeniden yükleyin.
diff --git a/tr/fdroid/index.html b/tr/fdroid/index.html
index e41a99ecab..6eae7328f9 100644
--- a/tr/fdroid/index.html
+++ b/tr/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">F-Droid ile SimpleX Chat</h2>
 
@@ -692,16 +697,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Geliştiriciler tarafından oluşturulan kararlı ve beta sürümler</p>
-                        <p>F-Droid istemcinize eklemek için <span class="hide-on-mobile">QR kodunu tarayın veya</span> bu URL'yi kullanın:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>F-Droid istemcinize eklemek için <span class='hide-on-mobile'>QR kodunu tarayın veya</span> bu URL'yi kullanın:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             İmza anahtarı parmak izi (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,25 +718,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org deposu</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">F-Droid.org tarafından oluşturulan kararlı sürümler</p>
                 <p class="mb-2">Bu depoya sürümler birkaç gün sonra eklenir.</p>
-                <p class="mb-2">SimpleX Chat ve F-Droid.org depoları farklı anahtarlarla imzalanır. Geçiş yapmak için <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">sohbet veritabanınızı dışa aktarın</a> ve uygulamayı yeniden yükleyin.</p>
+                <p class="mb-2">SimpleX Chat ve F-Droid.org depoları farklı anahtarlarla imzalanır. Geçiş yapmak için <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>sohbet veritabanınızı dışa aktarın</a> ve uygulamayı yeniden yükleyin.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/tr/file.md b/tr/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/tr/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/tr/file/index.html b/tr/file/index.html
index a8d65c48a4..b6c54e39d3 100644
--- a/tr/file/index.html
+++ b/tr/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/tr/index.html b/tr/index.html
index cc7be7e54b..bef7ebe5d3 100644
--- a/tr/index.html
+++ b/tr/index.html
@@ -60,6 +60,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/tr/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/tr/fdroid" title="SimpleX uygulaması F-Droid&#39;de"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta sürümü TestFlight&#39;ta"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta sürümü TestFlight&#39;ta" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Güvenlik Denetimleri" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/tr/index.md b/tr/index.md
new file mode 100644
index 0000000000..ac6615d3e9
--- /dev/null
+++ b/tr/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## Ağınızda
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Daha fazlasını öğrenin.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX uygulaması F-Droid'de](https://simplex.chat/tr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Güvenlik Denetimleri](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/tr/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/tr/why)
+
+## Kullanıcıları Tarafından Finanse Ediliyor
+
+Bağımsız kalmak için büyük kanallar ve topluluklar sunucuları için ödeme yapacak.
+
+Ve kullanıcılar artık SimpleX Chat'e yatırım yapabilir — kitle fonlaması başladı!
+
+[SimpleX Chat'e Yatırım Yap](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/tr/invitation.md b/tr/invitation.md
new file mode 100644
index 0000000000..274fb3cb47
--- /dev/null
+++ b/tr/invitation.md
@@ -0,0 +1,66 @@
+# SimpleX Chat ile bağlantı kurmak için tek kullanımlık bir bağlantı aldınız
+
+## Mobil cihazınızda veya tabletinizde SimpleX Chat uygulamasıyla QR kodunu tarayın.
+
+Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ — bağlantı URL'sinin hash bölümünde yer alır.
+
+SimpleX Chat'i henüz indirmediniz mi?
+
+Uygulamayı indirmek için aşağıdaki bağlantıları kullanın.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Mobil uygulamadan QR kodunu tarayın
+
+# SimpleX Chat ile bağlantı kurmak için tek kullanımlık bir bağlantı aldınız
+
+Bağlantı başlatmak için:
+
+SimpleX uygulamasını yükleyin
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid)
+
+1
+
+Uygulamada bağlanın
+
+SimpleX uygulamasını açın
+
+2
+
+Uygulamada "Bağlan" düğmesine dokunun
+
+3
+
+## SimpleX Chat uygulamasıyla QR kodunu tarayın
+
+Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ —
+bağlantı URL'sinin hash bölümünde yer alır.
+
+## Terminalde SimpleX Chat kurulumu
+
+Bu komutu kullanın:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+SimpleX Chat'i gör GitHub deposu İndirme veya kaynak koddan derleme talimatları için.
+
+---
+
+## SimpleX'i terminal için zaten yüklediyseniz
+
+Zaten yüklediyseniz Terminal için SimpleX Chat v1.0.0+, Aşağıdaki komutu kopyalayıp sohbette kullanın:
+
+## Katılın SimpleX
+
+Sizi sohbete katılmaya davet ediyoruz
+
+[Reddit grubuna katılın](https://www.reddit.com/r/SimpleXChat/) [GitHub'da bize katılın](https://github.com/simplex-chat) [Bize destek olmak için buradan bağış yapın](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Güncellemelerimizi almak için kaydolun
+
+---
+
+SimpleX' [masaüstü uygulamasını](https://simplex.chat/downloads) indirin
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/tr/fdroid)
diff --git a/tr/invitation/index.html b/tr/invitation/index.html
index b5ec1ba039..c57770f08d 100644
--- a/tr/invitation/index.html
+++ b/tr/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,28 +674,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">SimpleX Chat ile bağlantı kurmak için tek kullanımlık bir bağlantı aldınız</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Mobil cihazınızda veya tabletinizde SimpleX Chat uygulamasıyla QR kodunu tarayın.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ — bağlantı URL'sinin hash bölümünde yer alır.
+                Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ &mdash; bağlantı URL'sinin hash bölümünde yer alır.
             </p>
             <p class="text-grey-black dark:text-white text-base">SimpleX Chat'i henüz indirmediniz mi?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Uygulamayı indirmek için aşağıdaki bağlantıları kullanın.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">SimpleX uygulamasını yükleyin</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -748,7 +755,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Uygulamada <span class="text-active-blue">"Bağlan"</span> düğmesine dokunun</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Uygulamada <span class='text-active-blue'>"Bağlan"</span> düğmesine dokunun</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX Chat uygulamasıyla QR kodunu tarayın</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ —<br> bağlantı URL'sinin hash bölümünde yer alır.
+                            Bu bağlantıdaki genel anahtarlar ve mesaj kuyruğu adresi, bu sayfayı açtığınızda AĞ ÜZERİNDEN GÖNDERİLMEZ &mdash;<br> bağlantı URL'sinin hash bölümünde yer alır.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Terminalde SimpleX Chat kurulumu</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub deposu</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">SimpleX'i terminal için zaten yüklediyseniz</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Güncellemelerimizi almak için kaydolun</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="E-posta adresinizi girin">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">SimpleX' <a href="/downloads">masaüstü uygulamasını</a> indirin</p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/tr/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/tr/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/tr/messaging.md b/tr/messaging.md
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+++ b/tr/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## SimpleX neden benzersiz
+
+### Tam gizlilik elde edersiniz
+
+SimpleX, profilinizin, kişilerin ve meta verilerinizin gizliliğini korur ve bunları SimpleX ağ sunucularından ve diğer olası gözlemcilerden gizler.
+
+Mevcut tüm diğer mesajlaşma ağlarının aksine, SimpleX kullanıcılarına hiçbir kimlik atamaz — **rastgele sayılar bile yoktur**.
+
+### Spam ve kötüye kullanıma karşı koruma
+
+SimpleX ağında kimliğiniz veya sabit bir adresiniz olmadığı için, kimse size ulaşamaz; yalnızca tek kullanımlık veya geçici bir kullanıcı adresini QR kodu veya bağlantı olarak paylaşırsanız iletişim kurabilir.
+
+### Verilerinizin kontrolü sizde
+
+SimpleX, kullanıcı verilerini yalnızca uç cihazlarda ve **taşınabilir, şifreli bir veritabanı formatında** saklar — bu, başka bir cihaza aktarılabilir.
+
+Uçtan uca şifreli mesajlar, son cihaza ulaşana kadar SimpleX aktarma sunucularında geçici olarak saklanır ve ardından kalıcı olarak silinir.
+
+### SimpleX ağının sahibi sizsiniz
+
+SimpleX ağı tamamen merkeziyetsizdir ve kripto para birimleri veya internet dışında başka ağlara bağlı değildir.
+
+**Kendi sunucularınızla SimpleX'i kullanabilirsiniz** veya bizim sunduğumuz sunucuları kullanabilirsiniz — yine de tüm kullanıcılarla bağlantı kurabilirsiniz.
+
+# Kimliğiniz, profiliniz, kişileriniz ve metaverileriniz için tam gizlilik
+
+Diğer mesajlaşma ağlarının aksine, SimpleX **kullanıcılara hiçbir kimlik atamaz**. Kullanıcıları tanımlamak için telefon numaralarına, alan adı tabanlı adreslere (e-posta veya XMPP gibi), kullanıcı adlarına, genel anahtarlara veya rastgele sayılara dayanmaz — SimpleX sunucu sahipleri bile sunucularını kaç kişinin kullandığını bilmez.
+
+SimpleX, mesajları iletmek için [ikili anonim adresler](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) kullanır; bunlar tek yönlü mesaj kuyruklarından oluşur ve alınan ve gönderilen mesajlar için ayrıdır, genellikle farklı sunucular üzerinden iletilir.
+
+Bu tasarım, sizin ve iletişim kurduğunuz kişilerin gizliliğini korur ve bağlantıları SimpleX ağ sunucularından ve olası gözlemcilerden gizler. IP adresinizi sunuculardan gizlemek için **SimpleX sunucularına Tor üzerinden bağlanabilirsiniz**.
+
+# Spam ve kötüye kullanıma karşı en iyi koruma
+
+SimpleX ağında kimliğiniz olmadığı için, kimse size ulaşamaz; yalnızca tek kullanımlık veya geçici bir kullanıcı adresini QR kodu veya bağlantı olarak paylaşırsanız iletişim kurabilir.
+
+İsteğe bağlı kullanıcı adresi spam bağlantı istekleri göndermek için kullanılabilse de, bu adresi değiştirebilir veya tamamen silebilirsiniz; bağlantılarınız kaybolmaz.
+
+# Verilerinizin sahipliği, kontrolü ve güvenliği
+
+SimpleX Chat tüm kullanıcı verilerini yalnızca uç cihazlarda **taşınabilir ve şifreli bir veritabanı formatında** saklar; bu format dışa aktarılabilir ve desteklenen herhangi bir cihaza aktarılabilir.
+
+Uçtan uca şifreli mesajlar, son cihaza ulaşana kadar SimpleX aktarma sunucularında geçici olarak saklanır ve ardından kalıcı olarak silinir.
+
+Federasyonlu ağ sunucularının (ör. e-posta, XMPP veya Matrix) aksine, SimpleX sunucuları kullanıcı hesabı saklamaz, yalnızca mesajları iletir ve böylece tarafların gizliliği korunur.
+
+Gönderilen ve alınan sunucu trafiği arasında ortak bir kimlik veya şifreli metin yoktur — bu nedenle, bir gözlemci TLS ele geçirilse bile kimin kiminle iletişim kurduğunu kolayca tespit edemez.
+
+# Tamamen merkeziyetsiz — SimpleX ağının sahibi kullanıcılar
+
+**Kendi sunucularınızla SimpleX kullanabilirsiniz** ve yine de uygulamanın önceden yapılandırılmış sunucularını kullanan kişilerle iletişim kurabilirsiniz.
+
+SimpleX ağı [açık bir protokol](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) kullanır ve [sohbet botları geliştirmek için bir SDK](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript) sunar. Bu sayede kullanıcıların SimpleX Chat uygulamalarıyla etkileşime geçebileceği servisler oluşturabilirsiniz — hangi SimpleX servislerini geliştireceğinizi merakla bekliyoruz.
+
+SimpleX ağının geliştirilmesine aktif olarak katkıda bulunmak, örneğin SimpleX uygulama kullanıcıları için bir sohbet botu geliştirmek veya SimpleX Chat kütüphanesinin mobil uygulamalara entegrasyonunu ilerletmek isterseniz, [bizimle iletişime geçin](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) ve destek alın.
+
+## Özellikler
+
+Uçtan uca şifreli mesajlar, markdown ve düzenleme desteğiyle
+
+Uçtan uca şifreli
+resimler, videolar ve dosyalar
+
+Uçtan uca şifreli merkeziyetsiz gruplar — Sadece kullanıcılar bu grupların varlığını bilir
+
+Uçtan uca şifreli sesli mesajlar
+
+Kaybolan gizli sohbetler
+
+Uçtan uca şifreli
+sesli ve görüntülü aramalar
+
+Taşınabilir ve şifreli uygulama veri depolama — tüm profilinizi başka bir cihaza kolayca taşıyın
+
+Gizli mod —
+SimpleX Chat'te benzersiz
+
+## SimpleX'i gizli yapan nedir
+
+### Geçici, anonim çift yönlü kimlikler
+
+SimpleX, her kullanıcı bağlantısı veya grup üyesi için kendi geçici, anonim ve çift yönlü adreslerini ve kimlik bilgilerini kullanır.
+
+SimpleX, kullanıcı profili tanımlayıcıları olmadan mesaj göndermeye olanak tanır ve diğer alternatiflere göre daha iyi meta veri gizliliği sunar.
+
+### Ağ Dışı Anahtar Değişimi
+
+Birçok iletişim ağı, sunucu veya ağ sağlayıcıları tarafından yapılan MITM saldırılarına karşı savunmasızdır.
+
+Bunu önlemek için, SimpleX bağlantı adresini link veya QR kodu olarak paylaştığınızda tek kullanımlık anahtarları ağ dışı yollarla iletir.
+
+### İki Katmanlı Uçtan Uca Şifreleme
+
+Double-Ratchet protokolü —
+Perfect Forward Secrecy, inkar edilebilirlik ve ihlal sonrası kurtarma ile Off-the-Record mesajlar.
+
+Her kuyrukta NaCL kriptobox kullanılır, böylece TLS ihlal edilse bile mesaj kuyrukları arasındaki trafik ilişkilendirilemez.
+
+### Mesaj Bütünlüğü Doğrulaması
+
+Mesaj bütünlüğünü sağlamak için, mesajlar sıralı olarak numaralandırılır ve önceki mesajın hash'i eklenir.
+
+Bir mesaj eklendiğinde, silindiğinde veya değiştirildiğinde alıcı uyarılır.
+
+### Ek Sunucu Şifreleme Katmanı
+
+Alıcıya teslimat için ek sunucu şifreleme katmanı, TLS ihlal edilirse alınan ve gönderilen sunucu verileri arasındaki ilişkiyi önler.
+
+### Mesajları karıştırma, korelasyonu azaltma
+
+SimpleX sunucuları, düşük gecikmeli karıştırıcı düğümler olarak çalışır — gelen ve giden mesajların sırası farklıdır.
+
+### Güvenli Doğrulanmış TLS Taşıma Katmanı
+
+İstemci-sunucu bağlantıları için yalnızca güçlü algoritmalarla TLS 1.2/1.3 kullanılır.
+
+Sunucu parmak izleri ve kanal bağlama, MITM ve tekrar saldırılarını önler.
+
+Oturum saldırılarını önlemek için bağlantı devamı devre dışı bırakılmıştır.
+
+### İsteğe Bağlı Tor Erişimi
+
+IP adresinizi korumak için Tor veya başka bir taşıma katmanı ağı üzerinden sunuculara erişebilirsiniz.
+
+Android'de Tor ile SimpleX kullanmak için [Orbot uygulamasını](https://guardianproject.info/apps/org.torproject.android/) yükleyin ve SOCKS5 proxy'yi etkinleştirin veya [iOS'ta](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone) VPN kullanın.
+
+### Tek Yönlü Mesaj Kuyrukları
+
+Her mesaj kuyruğu, farklı gönderici ve alıcı adresleriyle mesajları yalnızca tek yönde iletir.
+
+Geleneksel mesaj aracılarına kıyasla, olası saldırı vektörleri ve mevcut metaveriler azaltılır.
+
+### Çoklu İçerik Doldurma Katmanları
+
+SimpleX, mesaj boyutu saldırılarını önlemek için her şifreleme katmanında içerik doldurma kullanır.
+
+Sunucu ve ağ gözlemcileri için aynı görünen farklı boyutlarda mesajlar üretir.
+
+## SimpleX-Ağı
+
+P2P ve federasyonlu ağların avantajlarını birleştirerek SimpleX, mümkün olan en iyi gizliliği sunar.
+
+### P2P ağlarının aksine
+
+Tüm mesajlar sunucular üzerinden gönderilir; bu, meta veri korumasını artırır ve daha güvenilir asenkron mesaj iletimi sağlar ve birçok sorunu önler .
+
+# P2P Mesajlaşma Protokolleriyle Karşılaştırma
+
+[Eşler arası](https://en.wikipedia.org/wiki/Peer-to-peer) mesajlaşma protokolleri ve uygulamaları, SimpleX'e kıyasla daha az güvenilir, analiz edilmesi daha karmaşık ve çeşitli saldırı türlerine karşı daha savunmasız olmalarına neden olan çeşitli sorunlara sahiptir.
+
+1. P2P ağları, mesajları yönlendirmek için [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) türlerine güvenir. DHT tasarımları, teslimat garantisi ile gecikme arasında denge kurmak zorundadır. P2P'ye kıyasla SimpleX, daha iyi teslimat garantisi ve daha düşük gecikme sunar çünkü bir mesaj birden fazla sunucu üzerinden yedekli ve paralel olarak gönderilebilir ve alıcı tarafından seçilen sunucular kullanılır. P2P ağlarında mesajlar *O(log N)* düğüm üzerinden sıralı olarak gönderilir ve düğümler bir algoritma ile seçilir.
+2. SimpleX tasarımı, çoğu P2P ağının aksine, hiçbir küresel kullanıcı kimliği içermez, geçici olanlar bile yoktur. Sadece geçici, ikili kimlikler kullanır ve bu da daha iyi anonimlik ve meta veri koruması sağlar.
+3. P2P, [MITM saldırısı](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) sorununu çözmez ve mevcut uygulamaların çoğu ilk anahtar değişimi için ağ dışı mesajlar kullanmaz. SimpleX ise ilk anahtar değişimi için ağ dışı mesajlar veya mevcut güvenli ve güvenilir bağlantılar kullanır.
+4. ——P2P uygulamaları internet servis sağlayıcıları tarafından engellenebilir (örneğin [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX ise taşıma bağımsızdır — standart web protokolleriyle, örneğin WebSockets ile çalışabilir.
+5. Bilinen tüm P2P ağları [Sybil saldırılarına](https://en.wikipedia.org/wiki/Sybil_attack) karşı savunmasızdır çünkü her düğüm tespit edilebilir ve ağ bir bütün olarak çalışır. Bilinen önlemler ya merkezi bir bileşen ya da pahalı bir [iş kanıtı](https://en.wikipedia.org/wiki/Proof_of_work) gerektirir. SimpleX ağı sunucu tespiti sağlamaz, parçalıdır ve birden fazla izole alt ağ ile çalışır, bu da ağ genelinde saldırıları imkansız kılar.
+6. P2P ağları, istemciler trafiği tekrar gönderip güçlendirebildiğinde [DRDoS saldırılarına](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) karşı savunmasız olabilir ve bu da tüm ağda hizmet reddine yol açabilir. SimpleX istemcileri yalnızca bilinen bağlantılardan gelen trafiği iletir ve bir saldırgan tarafından ağ genelinde trafiği güçlendirmek için kullanılamaz.
+
+---
+
+### Federasyonlu ağların aksine
+
+SimpleX aktarma sunucuları KULLANICI PROFİLLERİNİ, kişileri ve teslim edilen mesajları SAKLAMAZ ve birbirleriyle bağlantı kurmaz, ayrıca bir sunucu dizini yoktur.
+
+---
+
+### SimpleX Ağı
+
+Sunucular, kullanıcıları birbirine bağlamak için tek yönlü kuyruklar sağlar. Ancak ağın bağlantı grafiğini göremezler — bunu yalnızca kullanıcılar bilir.
+
+## SimpleX açıklıyor
+
+1. Kullanıcıların nasıl deneyimlediği
+
+2. Nasıl çalışır
+
+3. Sunucuların ne gördüğü
+
+1. Kullanıcıların nasıl deneyimlediği
+
+Kişiler ve gruplar oluşturabilir ve tıpkı diğer mesajlaşma programlarında olduğu gibi iki yönlü iletişim kurabilirsiniz.
+
+Tek yönlü kuyruklarla ve kullanıcı profil tanımlayıcıları olmadan nasıl çalışabilir?
+
+2. Nasıl çalışır
+
+Her bağlantı için, farklı sunucular üzerinden mesaj göndermek ve almak üzere iki ayrı mesaj kuyruğu kullanırsınız.
+
+Sunucular, kullanıcıların konuşmalarının veya bağlantılarının tam resmini görmeden mesajları tek yönlü olarak iletir.
+
+3. Sunucuların ne gördüğü
+
+Sunucular her kuyruk için ayrı, anonim oturum açma bilgileri kullanır ve hangi kullanıcıya ait olduğunu bilmez.
+
+Tor erişim sunucuları kullanarak kullanıcılar, meta veri gizliliğini artırabilir ve IP adresi korelasyonunu önleyebilir.
+
+## Diğer protokollerle karşılaştırma
+
+|  |  | Signal, büyük platformlar | XMPP / Matrix | P2P protokolleri |
+| --- | --- | --- | --- | --- |
+| Küresel bir kimlik gerektirir | Hayır – gizli | Evet [1] | Evet [2] | Evet [3] |
+| MITM saldırısı riski | Hayır – güvenli [4] | Evet [5] | Evet | Evet |
+| DNS sistemine bağımlılık | Hayır – dayanıklı | Evet | Evet | Hayır |
+| Tek veya merkezi ağ | Hayır – merkeziyetsiz | Evet | Hayır – federasyonlu [6] | Evet [7] |
+| Merkezi bileşen veya diğer ağ genelinde saldırılar | Hayır – dayanıklı | Evet | Evet [2] | Evet [8] |
+
+---
+
+1. Genellikle telefon numarasına, bazen kullanıcı adına dayalı
+2. DNS tabanlı adresler
+3. Genel anahtar veya başka bir küresel benzersiz kimlik
+4. SimpleX aktarıcıları uçtan uca şifrelemeyi tehlikeye atamaz. Olası bir ağ dışı kanal saldırısını önlemek için güvenlik kodunu doğrulayın
+5. Operatörün sunucuları ele geçirilirse. Signal ve diğer uygulamalarda bunu azaltmak için güvenlik kodu doğrulanabilir
+6. Kullanıcı meta verilerinin gizliliği korunmaz
+7. P2P dağıtık olsa da federasyonlu değildir — tek bir ağ olarak çalışır
+8. P2P ağlarının ya merkezi bir yönetimi vardır ya da tüm ağ tehlikeye girebilir — [Buraya bakın](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [Buraya bakın](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/tr/messaging/index.html b/tr/messaging/index.html
index 44a20fde2b..ea46bc22d5 100644
--- a/tr/messaging/index.html
+++ b/tr/messaging/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Tam gizlilik elde edersiniz</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Spam ve kötüye kullanıma<br>karşı koruma</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Verilerinizin kontrolü sizde</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX ağının sahibi sizsiniz</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX, kullanıcı profili tanımlayıcıları olmadan mesaj göndermeye olanak tanır ve diğer alternatiflere göre daha iyi meta veri gizliliği sunar.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
                 </div>
                 
@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Bunu önlemek için, SimpleX bağlantı adresini link veya QR kodu olarak paylaştığınızda tek kullanımlık anahtarları ağ dışı yollarla iletir.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
                 </div>
                 
@@ -1236,7 +1240,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Her kuyrukta NaCL kriptobox kullanılır, böylece TLS ihlal edilse bile mesaj kuyrukları arasındaki trafik ilişkilendirilemez.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
                 </div>
                 
@@ -1254,7 +1258,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Bir mesaj eklendiğinde, silindiğinde veya değiştirildiğinde alıcı uyarılır.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
                 </div>
                 
@@ -1270,7 +1274,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Alıcıya teslimat için ek sunucu şifreleme katmanı, TLS ihlal edilirse alınan ve gönderilen sunucu verileri arasındaki ilişkiyi önler.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
                 </div>
                 
@@ -1286,7 +1290,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX sunucuları, düşük gecikmeli karıştırıcı düğümler olarak çalışır — gelen ve giden mesajların sırası farklıdır.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
                     </div>
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@@ -1306,7 +1310,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Oturum saldırılarını önlemek için bağlantı devamı devre dışı bırakılmıştır.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
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@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Android'de Tor ile SimpleX kullanmak için <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot uygulamasını</a> yükleyin ve SOCKS5 proxy'yi etkinleştirin veya <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">iOS'ta</a> VPN kullanın.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
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@@ -1342,7 +1346,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Geleneksel mesaj aracılarına kıyasla, olası saldırı vektörleri ve mevcut metaveriler azaltılır.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
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@@ -1360,7 +1364,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Sunucu ve ağ gözlemcileri için aynı görünen farklı boyutlarda mesajlar üretir.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Kapatmak için dokunun</p>
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@@ -1842,17 +1846,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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diff --git a/tr/old/index.html b/tr/old/index.html
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@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1089,7 +1093,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Tam gizlilik elde edersiniz</h3>
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@@ -1140,7 +1144,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Spam ve kötüye kullanıma<br>karşı koruma</h3>
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@@ -1188,7 +1192,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Verilerinizin kontrolü sizde</h3>
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@@ -1239,7 +1243,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX ağının sahibi sizsiniz</h3>
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@@ -2150,17 +2154,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/tr/why.md b/tr/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/tr/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/tr/why/index.html b/tr/why/index.html
index 735669054c..a280118977 100644
--- a/tr/why/index.html
+++ b/tr/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/tr/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/transparency.md b/transparency.md
new file mode 100644
index 0000000000..282e65c89b
--- /dev/null
+++ b/transparency.md
@@ -0,0 +1,28 @@
+# Transparency Reports
+
+**Updated**: Feb 09, 2026
+
+SimpleX Chat Ltd. is a company registered in the UK – it develops communication software enabling users to operate and communicate via SimpleX network, without user profile identifiers of any kind, and without having their data hosted by any network infrastructure operators.
+
+This page will include any and all reports on requests for user data.
+
+In 2025 we received 12 requests from law enforcement of different countries. No responsive information was identified/provided.
+
+In 2024 we received enquiries from several law enforcement agencies seeking information on our procedures for handling data requests. We responded by noting that we operate under the UK law and will consider such requests pursuant to UK law.
+
+Our objective is to consistently ensure that no user data and absolute minimum of the metadata required for the network to function is available for disclosure by any infrastructure operators, under any circumstances.
+
+**Helpful resources**:
+- [Privacy policy](https://github.com/simplex-chat/simplex-chat/blob/stable/PRIVACY.md)
+- [Privacy and security: technical details and limitations](https://github.com/simplex-chat/simplex-chat/blob/stable/README.md#privacy-and-security-technical-details-and-limitations)
+- Whitepaper:
+  - [Trust in servers](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#trust-in-servers)
+  - [Encryption Primitives Used](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#encryption-primitives-used)
+  - [Threat model](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md#threat-model)
+- Security assessments:
+  - Trail of Bits, SimpleX cryptography and networking, [October 2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.md).
+  - Trail of Bits, the cryptographic review of SimpleX protocols design, [July 2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.md).
+
+Have a more specific question? Reach out to us via [SimpleX Chat](https://smp6.simplex.im/a#lrdvu2d8A1GumSmoKb2krQmtKhWXq-tyGpHuM7aMwsw) or via email [chat@simplex.chat](mailto:chat@simplex.chat).
+
+For any sensitive questions please use SimpleX Chat or encrypted email messages using the key for this address from [keys.openpgp.org](https://keys.openpgp.org/search?q=chat%40simplex.chat) (its fingerprint is `FB44 AF81 A45B DE32 7319 797C 8510 7E35 7D4A 17FC`) and make your key available for a secure reply.
diff --git a/transparency/index.html b/transparency/index.html
index 52df3b1fd8..efe5d108ed 100644
--- a/transparency/index.html
+++ b/transparency/index.html
@@ -53,6 +53,10 @@
         <meta name="Content-Type" content="text/html;charset=utf-8"/>
 
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/transparency.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#ffffff">
         <link href="/css/tailwind.css" rel="stylesheet"/>
         <link id="prism-theme" rel="stylesheet" href="/css/prism-light.min.css"/>
diff --git a/uk/contact.md b/uk/contact.md
new file mode 100644
index 0000000000..41a7029a34
--- /dev/null
+++ b/uk/contact.md
@@ -0,0 +1,66 @@
+# Ви отримали адресу для підключення в SimpleX Chat
+
+## Скануйте QR-код за допомогою додатка SimpleX Chat на своєму телефоні чи планшеті.
+
+Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки — вони містяться в хеш-фрагменті URL-посилання.
+
+Ще не завантажили SimpleX Chat?
+
+Скористайтеся посиланнями нижче, щоб завантажити додаток.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Сканувати QR-код з мобільного додатка
+
+# Ви отримали адресу для підключення в SimpleX Chat
+
+Щоб здійснити підключення:
+
+Встановити додаток SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid)
+
+1
+
+Підключитися в додатку
+
+Відкрити додаток SimpleX
+
+2
+
+Торкніться кнопки ‘підключити’ в додатку
+
+3
+
+## Скануйте QR-код за допомогою додатка SimpleX Chat
+
+Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки —
+вони містяться в хеш-фрагменті URL-посилання.
+
+## Встановлення SimpleX Chat для терміналу
+
+Використовуйте цю команду:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Дивіться SimpleX Chat Репозиторій GitHub для інструкції з того, як його завантажити чи скомпілювати з вихідного коду.
+
+---
+
+## Якщо ви вже встановили SimpleX Chat для терміналу
+
+Якщо ви вже встановили SimpleX Chat для терміналу v1.0.0+, скопіюйте команду нижче та використовуйте її в чаті:
+
+## Приєднатися SimpleX
+
+Ми запрошуємо вас приєднатися до розмови
+
+[Приєднуйтесь до спільноти REDDIT](https://www.reddit.com/r/SimpleXChat/) [Приєднуйтесь до нас на GitHub](https://github.com/simplex-chat) [Пожертвуйте тут, щоб допомогти нам](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Підпишіться, щоб отримувати наші оновлення
+
+---
+
+Отримати SimpleX [додаток для настільних комп'ютерів](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid)
diff --git a/uk/contact/index.html b/uk/contact/index.html
index 213bd93d64..c5ec050f3e 100644
--- a/uk/contact/index.html
+++ b/uk/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Ви отримали адресу для підключення в SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Скануйте QR-код за допомогою додатка SimpleX Chat на своєму телефоні чи планшеті.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки — вони містяться в хеш-фрагменті URL-посилання.
+                Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки &mdash; вони містяться в хеш-фрагменті URL-посилання.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ще не завантажили SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Скористайтеся посиланнями нижче, щоб завантажити додаток.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Встановити додаток SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Торкніться кнопки <span class="text-active-blue">‘підключити’</span> в додатку</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Торкніться кнопки <span class='text-active-blue'>‘підключити’</span> в додатку</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Скануйте QR-код за допомогою додатка SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки —<br> вони містяться в хеш-фрагменті URL-посилання.
+                            Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки &mdash;<br> вони містяться в хеш-фрагменті URL-посилання.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Встановлення SimpleX Chat для терміналу</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Репозиторій GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Якщо ви вже встановили SimpleX Chat для терміналу</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Підпишіться, щоб отримувати наші оновлення</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введіть свою електронну адресу">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Отримати SimpleX <a href="/downloads">додаток для настільних комп'ютерів</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/fdroid.md b/uk/fdroid.md
new file mode 100644
index 0000000000..1a1f80d833
--- /dev/null
+++ b/uk/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat через F-Droid
+
+### Репозитарій SimpleX Chat
+
+Стабільні та бета-версії, побудовані розробниками
+
+Щоб додати його до свого клієнта F-Droid, скануйте QR-код або використовуйте цей URL:
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+Відбиток підпису ключа (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### Репозитарій F-Droid.org
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+Стабільні версії, побудовані F-Droid.org
+
+Релізи в це репо відбуваються на кілька днів пізніше.
+
+SimpleX Chat та репозитарії F-Droid.org підписують збірки різними ключами. Щоб переключитися, будь ласка, [експортуйте](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device) базу даних чату та перевстановіть додаток.
diff --git a/uk/fdroid/index.html b/uk/fdroid/index.html
index 69d215204c..0f3dda0fc1 100644
--- a/uk/fdroid/index.html
+++ b/uk/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat через F-Droid</h2>
 
@@ -701,16 +706,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Стабільні та бета-версії, побудовані розробниками</p>
-                        <p>Щоб додати його до свого клієнта F-Droid, <span class="hide-on-mobile">скануйте QR-код або</span> використовуйте цей URL:</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p>Щоб додати його до свого клієнта F-Droid, <span class='hide-on-mobile'>скануйте QR-код або</span> використовуйте цей URL:</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             Відбиток підпису ключа (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,25 +727,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">Репозитарій F-Droid.org</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">Стабільні версії, побудовані F-Droid.org</p>
                 <p class="mb-2">Релізи в це репо відбуваються на кілька днів пізніше.</p>
-                <p class="mb-2">SimpleX Chat та репозитарії F-Droid.org підписують збірки різними ключами. Щоб переключитися, будь ласка, <a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">експортуйте</a> базу даних чату та перевстановіть додаток.</p>
+                <p class="mb-2">SimpleX Chat та репозитарії F-Droid.org підписують збірки різними ключами. Щоб переключитися, будь ласка, <a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>експортуйте</a> базу даних чату та перевстановіть додаток.</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/file.md b/uk/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/uk/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/uk/file/index.html b/uk/file/index.html
index 1047ba7071..0f7b86377c 100644
--- a/uk/file/index.html
+++ b/uk/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -830,17 +834,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/index.html b/uk/index.html
index 6eebfb70c5..dc92f62c5d 100644
--- a/uk/index.html
+++ b/uk/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/uk/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/uk/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/uk/index.md b/uk/index.md
new file mode 100644
index 0000000000..309dc05f6b
--- /dev/null
+++ b/uk/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [Дізнатися більше.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/uk/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/uk/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/uk/why)
+
+## Фінансується користувачами
+
+Щоб залишатися незалежними, великі канали та спільноти платитимуть за свої сервери.
+
+А тепер користувачі можуть інвестувати в SimpleX Chat — краудфандинг запущено!
+
+[Інвестувати в SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/uk/invitation.md b/uk/invitation.md
new file mode 100644
index 0000000000..64f9cecbad
--- /dev/null
+++ b/uk/invitation.md
@@ -0,0 +1,66 @@
+# Ви отримали 1-разове посилання для підключення в SimpleX Chat
+
+## Скануйте QR-код за допомогою додатка SimpleX Chat на своєму телефоні чи планшеті.
+
+Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки — вони містяться в хеш-фрагменті URL-посилання.
+
+Ще не завантажили SimpleX Chat?
+
+Скористайтеся посиланнями нижче, щоб завантажити додаток.
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+Сканувати QR-код з мобільного додатка
+
+# Ви отримали 1-разове посилання для підключення в SimpleX Chat
+
+Щоб здійснити підключення:
+
+Встановити додаток SimpleX
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid)
+
+1
+
+Підключитися в додатку
+
+Відкрити додаток SimpleX
+
+2
+
+Торкніться кнопки ‘підключити’ в додатку
+
+3
+
+## Скануйте QR-код за допомогою додатка SimpleX Chat
+
+Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки —
+вони містяться в хеш-фрагменті URL-посилання.
+
+## Встановлення SimpleX Chat для терміналу
+
+Використовуйте цю команду:
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+Дивіться SimpleX Chat Репозиторій GitHub для інструкції з того, як його завантажити чи скомпілювати з вихідного коду.
+
+---
+
+## Якщо ви вже встановили SimpleX Chat для терміналу
+
+Якщо ви вже встановили SimpleX Chat для терміналу v1.0.0+, скопіюйте команду нижче та використовуйте її в чаті:
+
+## Приєднатися SimpleX
+
+Ми запрошуємо вас приєднатися до розмови
+
+[Приєднуйтесь до спільноти REDDIT](https://www.reddit.com/r/SimpleXChat/) [Приєднуйтесь до нас на GitHub](https://github.com/simplex-chat) [Пожертвуйте тут, щоб допомогти нам](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+Підпишіться, щоб отримувати наші оновлення
+
+---
+
+Отримати SimpleX [додаток для настільних комп'ютерів](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/uk/fdroid)
diff --git a/uk/invitation/index.html b/uk/invitation/index.html
index b933d11d73..1c005cf116 100644
--- a/uk/invitation/index.html
+++ b/uk/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,28 +683,31 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">Ви отримали 1-разове посилання для підключення в SimpleX Chat</h1>
             <h2 class="text-[20px] leading-[28px] text-[#606C71] dark:text-white font-bold max-w-[475px] mb-[80px] secondary-header-contact">Скануйте QR-код за допомогою додатка SimpleX Chat на своєму телефоні чи планшеті.</h2>
             <p class="text-grey-black dark:text-white text-base mb-[16px]">
-                Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки — вони містяться в хеш-фрагменті URL-посилання.
+                Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки &mdash; вони містяться в хеш-фрагменті URL-посилання.
             </p>
             <p class="text-grey-black dark:text-white text-base">Ще не завантажили SimpleX Chat?</p>
             <p class="text-grey-black dark:text-white text-base mb-[24px]">Скористайтеся посиланнями нижче, щоб завантажити додаток.</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">Встановити додаток SimpleX</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -757,7 +764,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <div class="flex flex-col justify-center items-center w-full max-w-[468px] h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 relative d-none-if-js-disabled">
-                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Торкніться кнопки <span class="text-active-blue">‘підключити’</span> в додатку</p>
+                <p class="text-xl font-medium text-grey-black dark:text-white max-w-[230px] text-center">Торкніться кнопки <span class='text-active-blue'>‘підключити’</span> в додатку</p>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
                     <p class="text-base text-white font-bold leading-[36px]">3</p>
@@ -778,14 +785,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Скануйте QR-код за допомогою додатка SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки —<br> вони містяться в хеш-фрагменті URL-посилання.
+                            Публічні ключі та адреса черги повідомлень в цьому посиланні НЕ відправляються по мережі під час перегляду цієї сторінки &mdash;<br> вони містяться в хеш-фрагменті URL-посилання.
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Встановлення SimpleX Chat для терміналу</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">Репозиторій GitHub</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">Якщо ви вже встановили SimpleX Chat для терміналу</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Підпишіться, щоб отримувати наші оновлення</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введіть свою електронну адресу">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">Отримати SimpleX <a href="/downloads">додаток для настільних комп'ютерів</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/messaging.md b/uk/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## Чому SimpleX є унікальним
+
+### Ви маєте повну конфіденційність
+
+SimpleX захищає конфіденційність вашого профілю, контактів та метаданих, приховуючи їх від серверів мережі SimpleX та будь-яких спостерігачів.
+
+На відміну від будь-якої іншої існуючої мережі для обміну повідомленнями, у SimpleX немає ідентифікаторів, призначених користувачам — **не навіть випадкових чисел**.
+
+### Вас захищено від спаму та зловживань
+
+Оскільки у вас немає ідентифікатора або фіксованої адреси в мережі SimpleX, ніхто не може зв'язатися з вами, якщо ви не поділитеся одноразовою або тимчасовою адресою користувача, як QR-кодом або посиланням.
+
+### Ви контролюєте свої дані
+
+SimpleX зберігає всі дані користувачів на пристроях клієнтів у **переносному зашифрованому форматі бази даних** — його можна передавати на інший пристрій.
+
+Зашифровані повідомлення від кінця до кінця тимчасово зберігаються на ретрансляційних серверах SimpleX до їх отримання, після чого вони назавжди видаляються.
+
+### Ви власник мережі SimpleX
+
+Мережа SimpleX повністю децентралізована та незалежна від будь-якої криптовалюти або будь-якої іншої мережі, окрім Інтернету.
+
+Ви можете **використовувати SimpleX з власними серверами** або з серверами, які ми надаємо — і все одно підключатися до будь-якого користувача.
+
+# Повна конфіденційність вашої ідентичності, профілю, контактів та метаданих
+
+На відміну від інших мереж для обміну повідомленнями, у SimpleX **немає ідентифікаторів, призначених користувачам**. Він не покладається на номери телефонів, адреси на основі доменів (як електронна пошта або XMPP), імена користувачів, публічні ключі або навіть випадкові числа для ідентифікації своїх користувачів — оператори серверів SimpleX не знають, скільки людей використовують їхні сервери.
+
+Для доставки повідомлень SimpleX використовує [парні анонімні адреси](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) однобічних черг повідомлень, окремо для отриманих та відправлених повідомлень, зазвичай через різні сервери.
+
+Цей дизайн захищає конфіденційність того, з ким ви спілкуєтесь, приховуючи це від серверів мережі SimpleX та від будь-яких спостерігачів. Щоб приховати вашу IP-адресу від серверів, ви можете **підключатися до серверів SimpleX через Tor**.
+
+# Найкращий захист від спаму та зловживань
+
+Оскільки у вас немає ідентифікатора в мережі SimpleX, ніхто не може зв'язатися з вами, якщо ви не поділитеся одноразовою або тимчасовою адресою користувача, як QR-кодом або посиланням.
+
+Навіть з необов'язковою адресою користувача, яка може бути використана для відправки спамових запитань на зв'язок, ви можете змінити або повністю видалити її, не втрачаючи жодного з ваших з'єднань.
+
+# Власність, контроль та безпека ваших даних
+
+SimpleX Chat зберігає всі дані користувачів лише на пристроях клієнтів за допомогою **переносного зашифрованого формату бази даних**, який можна експортувати і передавати на будь-який підтримуваний пристрій.
+
+Зашифровані повідомлення від кінця до кінця тимчасово зберігаються на ретрансляційних серверах SimpleX до їх отримання, після чого вони назавжди видаляються.
+
+На відміну від федеративних мереж серверів (електронна пошта, XMPP або Matrix), сервери SimpleX не зберігають облікові записи користувачів, вони лише ретранслюють повідомлення, захищаючи приватність обох сторін.
+
+Між надісланим і отриманим серверним трафіком немає спільних ідентифікаторів чи шифрованого тексту — якщо хтось його спостерігає, він не може легко визначити, хто спілкується з ким, навіть якщо TLS скомпрометовано.
+
+# Повністю децентралізована — користувачі володіють мережею SimpleX
+
+Ви можете **використовувати SimpleX зі своїми власними серверами** і при цьому спілкуватися з людьми, які використовують сервери, попередньо налаштовані в додатках.
+
+Мережа SimpleX використовує [відкритий протокол](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md) і надає [SDK для створення чат-ботів](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript), що дозволяє реалізувати сервіси, з якими користувачі можуть взаємодіяти через додатки SimpleX Chat — ми справді чекаємо, щоб побачити, які сервіси SimpleX ви створите.
+
+Якщо ви плануєте розробляти для мережі SimpleX, наприклад, чат-бота для користувачів додатка SimpleX або інтеграцію бібліотеки SimpleX Chat у ваші мобільні додатки, будь ласка, [зв'яжіться з нами](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D) для отримання порад та підтримки.
+
+## Особливості
+
+Повідомлення з шифруванням від кінця до кінця з можливістю використання Markdown та редагування
+
+Зображення, відео та файли з шифруванням від кінця до кінця
+
+Децентралізовані групи з шифруванням від кінця до кінця — тільки користувачі знають про їх існування
+
+Голосові повідомлення з шифруванням від кінця до кінця
+
+Зникнення повідомлень
+
+Дзвінки з шифруванням від кінця до кінця для аудіо та відео
+
+Переносне зашифроване зберігання додатку — переміщуйте профіль на інший пристрій
+
+Режим інкогніто —
+унікальний для SimpleX Chat
+
+## Що робить SimpleX конфіденційним
+
+### Тимчасові анонімні парні ідентифікатори
+
+SimpleX використовує тимчасові анонімні парні адреси та облікові дані для кожного користувача, контакту чи учасника групи.
+
+Це дозволяє доставляти повідомлення без ідентифікаторів профілю користувача та забезпечує кращу конфіденційність метаданих, ніж альтернативи.
+
+### Позаканальний обмін ключами
+
+Багато комунікаційних мереж вразливі до MITM-атак серверів чи постачальників мережі.
+
+Щоб запобігти цьому, програми SimpleX передають одноразові ключі позаканально, коли ви ділитесь адресою як посиланням або QR-кодом.
+
+### 2 рівні шифрування від кінця до кінця
+
+Протокол подвійної рейки — OTR-повідомлення з ідеальною передачею секрету та відновленням злому.
+
+NaCL криптокоробка в кожній черзі для запобігання кореляції трафіку між чергами повідомлень у разі компрометації TLS.
+
+### Перевірка цілісності повідомлення
+
+Для гарантії цілісності повідомлення пронумеровані послідовно та містять хеш попереднього повідомлення.
+
+Якщо будь-яке повідомлення додається, вилучається чи змінюється, отримувач буде проінформований.
+
+### Додатковий рівень шифрування сервера
+
+Додатковий рівень шифрування сервера для доставки отримувачу для запобігання кореляції між отриманим та відісланим трафіком сервера у разі компрометації TLS.
+
+### Змішування повідомлень для зменшення кореляції
+
+Сервери SimpleX виступають як вузли низької затримки для змішування — вхідні та вихідні повідомлення мають різний порядок.
+
+### Безпечний аутентифікований транспорт TLS
+
+Використовується лише TLS 1.2/1.3 із сильними алгоритмами для з'єднань клієнт-сервер.
+
+Відбиток сервера та зв'язування каналу запобігають MITM та атакам повтору.
+
+Відновлення з'єднання вимкнено для запобігання атакам на сесію.
+
+### Опційний доступ через Tor
+
+Для захисту вашої IP-адреси ви можете отримати доступ до серверів через Tor чи іншу транспортну оверлейну мережу.
+
+Для використання SimpleX через Tor, будь ласка, встановіть [додаток Orbot](https://guardianproject.info/apps/org.torproject.android/) та активуйте SOCKS5-проксі (або VPN [на iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### Однобічні черги повідомлень
+
+Кожна черга повідомлень передає повідомлення в одному напрямку, з різними адресами для відправки та отримання.
+
+Це зменшує вектори атак порівняно із традиційними брокерами повідомлень та доступними метаданими.
+
+### Кілька рівнів наповнення вмісту
+
+SimpleX використовує наповнення вмісту для кожного шару шифрування для ускладнення атак за розміром повідомлень.
+
+Це забезпечує, що повідомлення різних розмірів виглядають однаково для серверів та спостерігачів мережі.
+
+## SimpleX Network
+
+SimpleX Chat надає найкращу конфіденційність, поєднуючи переваги P2P та федеративних мереж.
+
+### На відміну від мереж P2P
+
+Всі повідомлення відправляються через сервери, що забезпечує кращу конфіденційність метаданих та надійну асинхронну доставку повідомлень, уникаючи багатьох .
+
+# Порівняння з протоколами P2P-повідомлень
+
+[Протоколи та додатки для P2P-зв'язку](https://en.wikipedia.org/wiki/Peer-to-peer) мають різні проблеми, які роблять їх менш надійними порівняно із SimpleX, складнішими для аналізу та вразливими до кількох типів атак.
+
+1. P2P-мережі покладаються на якусь варіацію [розподіленої хеш-таблиці (DHT)](https://en.wikipedia.org/wiki/Distributed_hash_table) для маршрутизації повідомлень. Дизайни DHT повинні балансувати гарантію доставки та затримку. У SimpleX є як краща гарантія доставки, так і менша затримка порівняно із P2P, оскільки повідомлення може передаватися паралельно кількома серверами, використовуючи сервери, обрані отримувачем. У P2P-мережах повідомлення проходить через вузли *O(log N)* послідовно, використовуючи вузли, обрані алгоритмом.
+2. У дизайні SimpleX, на відміну від більшості P2P-мереж, немає жодних глобальних ідентифікаторів користувачів будь-якого виду, навіть тимчасових, та використовуються лише тимчасові парні ідентифікатори, що забезпечує кращу анонімність та захист метаданих.
+3. P2P не вирішує проблему атаки [MITM](https://en.wikipedia.org/wiki/Man-in-the-middle_attack), і більшість існуючих реалізацій не використовують поза каналом повідомлень для початкового обміну ключами. SimpleX використовує поза каналом повідомлень або, у деяких випадках, передбачені і безпечні з'єднання для початкового обміну ключами.
+4. Реалізації P2P можуть бути заблоковані деякими інтернет-провайдерами (наприклад, [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX є незалежним від транспорту — він може працювати через стандартні веб-протоколи, наприклад, WebSockets.
+5. Всі відомі P2P-мережі можуть бути вразливими до атаки [Sybil](https://en.wikipedia.org/wiki/Sybil_attack), оскільки кожен вузол є відкритим, і мережа працює як ціле. Відомі заходи для пом'якшення цієї атаки вимагають або централізованого компонента, або дорогого [доказу роботи](https://en.wikipedia.org/wiki/Proof_of_work). Мережа SimpleX не має виявності сервера, вона роздроблена і працює як кілька ізольованих підмереж, що робить неможливими атаки на всю мережу.
+6. P2P-мережі можуть бути вразливими до атаки [DRDoS](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), коли клієнти можуть ребродкастити та збільшувати трафік, що призводить до відмови в обслуговуванні на рівні всієї мережі. Клієнти SimpleX лише пересилають трафік від відомого підключення і не можуть бути використані зловмисником для збільшення трафіку в усій мережі.
+
+---
+
+### На відміну від федеративних мереж
+
+Сервери SimpleX Chat НЕ зберігають профілі користувачів, контакти та доставлені повідомлення, НЕ підключаються один до одного, і НЕ існує каталог серверів.
+
+---
+
+### Мережа SimpleX
+
+сервери надають однобічні черги для з'єднання користувачів, але вони не мають видимості графа підключень в мережі — лише користувачі.
+
+## Пояснення SimpleX
+
+1. Що відчувають користувачі
+
+2. Як це працює
+
+3. Що бачать сервери
+
+1. Що відчувають користувачі
+
+Ви можете створювати контакти та групи і вести двосторонні розмови, як у будь-якому іншому месенджері.
+
+Як це може працювати з однобічними чергами та без ідентифікаторів профілю користувача?
+
+2. Як це працює
+
+Для кожного з'єднання ви використовуєте дві окремі черги обміну повідомленнями для відправки та отримання повідомлень через різні сервери.
+
+Сервери передають повідомлення тільки в одному напрямку, не маючи повної картини розмов або підключень користувача.
+
+3. Що бачать сервери
+
+Сервери мають окремі анонімні облікові дані для кожної черги і не знають, які користувачі до них відносяться.
+
+Користувачі можуть додатково підвищити конфіденційність метаданих, використовуючи Tor для доступу до серверів, що запобігає кореляції за IP-адресою.
+
+## Порівняння з іншими протоколами
+
+|  |  | Signal, великі платформи | XMPP, Matrix | Протоколи P2P |
+| --- | --- | --- | --- | --- |
+| Потребує глобального ідентифікатора | Ні - конфіденційно | Так [1] | Так [2] | Так [3] |
+| Можливість MITM | Ні - безпечно [4] | Так [5] | Так | Так |
+| Залежність від DNS | Ні - стійко | Так | Так | Ні |
+| Одна чи централізована мережа | Ні - децентралізовано | Так | Ні - федеративно [6] | Так [7] |
+| Центральний компонент чи інша атака на всю мережу | Ні - стійко | Так | Так [2] | Так [8] |
+
+---
+
+1. Зазвичай базується на номері телефону, у деяких випадках на іменах користувачів
+2. Адреси, засновані на DNS
+3. Відкритий ключ чи який-небудь інший глобально унікальний ідентифікатор
+4. Ретранслятори SimpleX не можуть порушити e2e-шифрування. Перевірте безпековий код для зменшення ризику атаки на зовнішньобандовий канал
+5. Якщо сервери оператора порушені. Перевірте безпековий код в Signal та деяких інших додатках для зменшення ризику
+6. Не захищає конфіденційність метаданих користувачів
+7. Хоча P2P є розподіленими, вони не є федеративними — вони працюють як одна мережа
+8. Мережі P2P мають або центральний орган управління, або всю мережу можна порушити — [дивіться тут](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [дивіться тут](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/uk/messaging/index.html b/uk/messaging/index.html
index e8a7ff8bd8..f35ec0fd8b 100644
--- a/uk/messaging/index.html
+++ b/uk/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви маєте повну конфіденційність</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вас захищено<br>від спаму та зловживань</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви контролюєте свої дані</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви власник мережі SimpleX</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Це дозволяє доставляти повідомлення без ідентифікаторів профілю користувача та забезпечує кращу конфіденційність метаданих, ніж альтернативи.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Щоб запобігти цьому, програми SimpleX передають одноразові ключі позаканально, коли ви ділитесь адресою як посиланням або QR-кодом.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">NaCL криптокоробка в кожній черзі для запобігання кореляції трафіку між чергами повідомлень у разі компрометації TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Якщо будь-яке повідомлення додається, вилучається чи змінюється, отримувач буде проінформований.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Додатковий рівень шифрування сервера для доставки отримувачу для запобігання кореляції між отриманим та відісланим трафіком сервера у разі компрометації TLS.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Сервери SimpleX виступають як вузли низької затримки для змішування — вхідні та вихідні повідомлення мають різний порядок.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Відновлення з'єднання вимкнено для запобігання атакам на сесію.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Для використання SimpleX через Tor, будь ласка, встановіть <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">додаток Orbot</a> та активуйте SOCKS5-проксі (або VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">на iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Це зменшує вектори атак порівняно із традиційними брокерами повідомлень та доступними метаданими.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">Це забезпечує, що повідомлення різних розмірів виглядають однаково для серверів та спостерігачів мережі.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/old/index.html b/uk/old/index.html
index 590f45b76a..e4c03f9091 100644
--- a/uk/old/index.html
+++ b/uk/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,13 +683,14 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head></head><body><div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+        
+<div class="first-two-sections pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="md:flex md:flex-col-reverse md:items-center xl:flex xl:flex-row xl:items-start relative xl:justify-between xl:gap-10 container">
         <div class="">
             <section class="xl:h-[calc(100vh-66px)] hero-section-1 xl:max-h-[888px] m-auto w-full flex items-center justify-between landing-page-header px-5">
                 <div class="xl:h-full flex flex-col items-center xl:items-start xl:justify-around w-full landing-page-header-div">
                     
-                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="">
+                    <img class="static-phone-mobile md:hidden" src="/img/new/mobile-hero.png" alt="" />
 
                     <article class="w-full xl:max-w-[600px] landing-page-header-article">
                         <h1 class="primary-header text-center xl:text-left xl:rtl:text-right font-bold text-[38px] md:text-[55px] leading-[46px] md:leading-[63px] mb-2 xl:mb-8">Приватність переосмислена</h1>
@@ -730,7 +735,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -749,10 +754,10 @@ window.addEventListener('click',(e)=>{
     Багато користувачів запитували: <em>якщо у SimpleX немає ідентифікаторів користувачів, як він може знати, куди відправити повідомлення?</em>
 </p>
 <p>
-    Для доставки повідомлень, замість ідентифікаторів користувачів, які використовують усі інші мережі, SimpleX використовує тимчасові анонімні парні ідентифікатори черг повідомлень, окремі для кожного вашого підключення — тут немає довгострокових ідентифікаторів.
+    Для доставки повідомлень, замість ідентифікаторів користувачів, які використовують усі інші мережі, SimpleX використовує тимчасові анонімні парні ідентифікатори черг повідомлень, окремі для кожного вашого підключення &mdash; тут немає довгострокових ідентифікаторів.
 </p>
 <p>
-    Ви визначаєте, який(кі) сервер(и) використовувати для отримання повідомлень, ваші контакти — сервери, які ви використовуєте для відправки повідомлень їм. Кожна розмова, ймовірно, використовує два різних сервери.
+    Ви визначаєте, який(кі) сервер(и) використовувати для отримання повідомлень, ваші контакти &mdash; сервери, які ви використовуєте для відправки повідомлень їм. Кожна розмова, ймовірно, використовує два різних сервери.
 </p>
 <p>
     Цей дизайн запобігає витоку метаданих будь-яких користувачів на рівні додатка. Для подальшого покращення конфіденційності та захисту вашої IP-адреси ви можете підключитися до серверів обміну повідомленнями через Tor.
@@ -761,7 +766,7 @@ window.addEventListener('click',(e)=>{
     Тільки пристрої клієнта зберігають профілі користувачів, контакти та групи; повідомлення відправляються із шифруванням від кінця до кінця з двома шарами.
 </p>
 <p>
-    Докладніше читайте у <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">білетному запису SimpleX</a>.
+    Докладніше читайте у <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>білетному запису SimpleX</a>.
 </p>
                         </div>
                     </div>
@@ -778,7 +783,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -817,7 +822,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -838,7 +843,7 @@ window.addEventListener('click',(e)=>{
                                 <img class="h-[24px] mb-[8px] w-auto block dark:hidden" src="/img/whonix-light.png" alt="Whonix">
                                 <img class="h-[24px] mb-[8px] w-auto hidden dark:block" src="/img/whonix-dark.png" alt="Whonix">
                             </a>
-                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&amp;sort_by=date&amp;rm=search" target="_blank">
+                            <a class="block rounded overflow-hidden" title="publication" href="https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search" target="_blank">
                                 <img class="h-[40px] w-auto block dark:hidden" src="/img/heise-light.png" alt="Heise Online">
                                 <img class="h-[40px] w-auto hidden dark:block" src="/img/heise-dark.png" alt="Heise Online">
                             </a>
@@ -854,11 +859,11 @@ window.addEventListener('click',(e)=>{
                         <div>
                             <p class="text-black dark:text-white hidden md:block text-center xl:text-left xl:rtl:text-right text-[16px] leading-[26px] mb-[11px] md:mt-6">Отримати SimpleX <a href="/downloads">додаток для настільних комп'ютерів</a></p>
                             <div class="socials flex items-center justify-center xl:justify-start gap-4 flex-wrap mt-[30px]">
-                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                                <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+                                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+                                <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+                                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
                             </div>
                         </div>
                     </article>
@@ -869,15 +874,15 @@ window.addEventListener('click',(e)=>{
                 <div class="h-[calc(100%-81.42px)] w-full flex flex-col items-start justify-around">
                     <div class="hero-video-phone-container w-full xl:hidden">
                         <div class="hidden relative md:flex items-center justify-center">
-                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg">
-                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls="">
+                            <img id="hero-video-phone-Background hidden md:block" src="/img/new/tab-video.svg" />
+                            <video class="absolute rounded-lg top-10 w-[235px] ml-[-6px] mt-1" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
 
                             
                         </div>
                         <div class="w-full md:hidden my-10 relative flex items-center justify-center bg-[#071C46]">
-                            <video class="w-full" controls="">
+                            <video class="w-full" controls>
                                 <source src="/video/connect.mp4" type="video/mp4">
                             </video>
                             
@@ -906,10 +911,10 @@ window.addEventListener('click',(e)=>{
             </section>
         </div>
         <div class="hero-phone-background hidden md:flex md:static md:max-w-[490px] md:mb-6 xl:mb-0 xl:flex items-center justify-center h-fit xl:h-[calc(100vh-66px)] xl:max-h-[888px] xl:min-w-[600px] xl:sticky top-[66px]">
-            <img id="hero-phone-light" class="only-light">
-            <img id="hero-phone-dark" class="only-dark">
+            <img id="hero-phone-light" class="only-light"/>
+            <img id="hero-phone-dark" class="only-dark"/>
             <div id="hero-phone-preload" style="display: none"></div>
-            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls="">
+            <video id="hero-phone-video" class="absolute hidden rounded-[12px] bg-black w-[238px] mr-[-4px] mt-[14px]" controls>
                 <source src="/video/connect.mp4" type="video/mp4">
             </video>
         </div>
@@ -931,8 +936,8 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-privacy" class="bg-secondary-bg-light dark:bg-secondary-bg-dark py-[90px] px-5 lg:h-[888px]">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Чому конфіденційність <span class="gradient-text">має значення</span></h2>
-        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Збереження конфіденційності ваших метаданих — <span class="text-active-blue">з ким ви спілкуєтеся</span> — захищає вас від:</p>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-4 md:mb-8">Чому конфіденційність <span class='gradient-text'>має значення</span></h2>
+        <p class="text-center text-[18px] md:text-[20px] font-medium mb-7 md:mb-16 lg:mb-20 text-black dark:text-white">Збереження конфіденційності ваших метаданих &mdash; <span class='text-active-blue'>з ким ви спілкуєтеся</span> &mdash; захищає вас від:</p>
         <div class="flex flex-col lg:flex-row gap-[20px] mb-[62px] lg:mb-[90px]">
 
             
@@ -960,7 +965,7 @@ window.addEventListener('click',(e)=>{
     Інтернет-роздрібники знають, що люди з низьким доходом частіше роблять термінові покупки, тому вони можуть встановлювати вищі ціни або скасовувати знижки.
 </p>
 <p>
-    Деякі фінансові та страхові компанії використовують соціальні графи для визначення ставок та страхових премій. Це часто змушує людей з низькими доходами платити більше — це відомо як <a href="https://fairbydesign.com/povertypremium/" target="_blank">'поширений преміум'</a>.
+    Деякі фінансові та страхові компанії використовують соціальні графи для визначення ставок та страхових премій. Це часто змушує людей з низькими доходами платити більше &mdash; це відомо як <a href='https://fairbydesign.com/povertypremium/' target='_blank'>'поширений преміум'</a>.
 </p>
 <p>
     Мережа SimpleX краще захищає конфіденційність ваших з'єднань, ніж будь-яка інша альтернатива, повністю запобігаючи тому, щоб ваш соціальний граф став доступним для будь-яких компаній чи організацій. Навіть коли люди використовують сервери, попередньо налаштовані в додатках SimpleX Chat, оператори серверів не знають кількості користувачів або їхніх з'єднань.
@@ -974,7 +979,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1001,7 +1006,7 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Не так давно ми спостерігали, як великі вибори маніпулювалися <a href="https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal" target="_blank">поважною консалтинговою компанією</a>, яка використовувала наші соціальні графи для спотворення нашого уявлення про реальний світ та маніпулювання нашими голосами.
+    Не так давно ми спостерігали, як великі вибори маніпулювалися <a href='https://en.wikipedia.org/wiki/Facebook–Cambridge_Analytica_data_scandal' target='_blank'>поважною консалтинговою компанією</a>, яка використовувала наші соціальні графи для спотворення нашого уявлення про реальний світ та маніпулювання нашими голосами.
 </p>
 <p>
     Щоб бути об'єктивним та приймати незалежні рішення, вам потрібно контролювати ваш інформаційний простір. Це можливо лише за умови використання приватної мережі для спілкування, яка не має доступу до вашого соціального графа.
@@ -1018,7 +1023,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1045,16 +1050,16 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    Кожен повинен турбуватися про конфіденційність та безпеку свого спілкування — безпечні розмови можуть поставити вас під загрозу, навіть якщо у вас немає чого приховувати.
+    Кожен повинен турбуватися про конфіденційність та безпеку свого спілкування &mdash; безпечні розмови можуть поставити вас під загрозу, навіть якщо у вас немає чого приховувати.
 </p>
 <p>
-    Однією з найшокуючих історій є досвід <a href="https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi" target="_blank">Мохамеду Ульд Слахі</a>, описаний в його мемуарах і показаний у фільмі "Мавританець". Його посадили в табір Гуантанамо без суду і мукили там 15 років після телефонного дзвінка йому родичеві в Афганістані, під підозрою в причетності до атак 11 вересня, навіть не дивлячись на те, що він проживав у Німеччині протягом попередніх 10 років.
+    Однією з найшокуючих історій є досвід <a href='https://en.wikipedia.org/wiki/Mohamedou_Ould_Slahi' target='_blank'>Мохамеду Ульд Слахі</a>, описаний в його мемуарах і показаний у фільмі "Мавританець". Його посадили в табір Гуантанамо без суду і мукили там 15 років після телефонного дзвінка йому родичеві в Афганістані, під підозрою в причетності до атак 11 вересня, навіть не дивлячись на те, що він проживав у Німеччині протягом попередніх 10 років.
 </p>
 <p>
-    Звичайних людей арештовують за те, що вони публікують онлайн, навіть через свої 'анонімні' облікові записи, <a href="https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html" target="_blank">навіть у демократичних країнах</a>.
+    Звичайних людей арештовують за те, що вони публікують онлайн, навіть через свої 'анонімні' облікові записи, <a href='https://www.dailymail.co.uk/news/article-11282263/Moment-police-swoop-house-devout-catholic-mother-malicious-online-posts.html' target='_blank'>навіть у демократичних країнах</a>.
 </p>
 <p>
-    Недостатньо використовувати зашифрований від кінця до кінця месенджер; ми всі повинні використовувати месенджери, які захищають конфіденційність наших особистих мереж — з ким ми з'єднані.
+    Недостатньо використовувати зашифрований від кінця до кінця месенджер; ми всі повинні використовувати месенджери, які захищають конфіденційність наших особистих мереж &mdash; з ким ми з'єднані.
 </p>
 
                         </div>
@@ -1065,7 +1070,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1083,7 +1088,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="why-simplex" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-0 sm:px-1 xl:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Чому SimpleX є <span class="gradient-text">унікальним</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-14 px-5 sm:px-4">Чому SimpleX є <span class='gradient-text'>унікальним</span></h2>
 
         <div class="swiper unique-swiper px-5 sm:px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1098,7 +1103,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви маєте повну конфіденційність</h3>
                             </div>
 
@@ -1125,7 +1130,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Додаткова інформація</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1133,7 +1138,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Приховати інформацію</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1149,7 +1154,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Вас захищено<br>від спаму та зловживань</h3>
                             </div>
 
@@ -1173,7 +1178,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Додаткова інформація</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1181,7 +1186,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Приховати інформацію</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1197,7 +1202,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви контролюєте свої дані</h3>
                             </div>
 
@@ -1205,7 +1210,7 @@ window.addEventListener('click',(e)=>{
                                 
                                     <div class="w-full max-w-[541px] text-[16px] leading-[24px] tracking-[0.02em] mb-[36px] text-grey-black dark:text-white text-center md:text-left md:rtl:text-right">
                                         <p style="padding-bottom:5px;">
-    SimpleX зберігає всі дані користувачів на пристроях клієнтів у <strong>переносному зашифрованому форматі бази даних</strong> — його можна передавати на інший пристрій.
+    SimpleX зберігає всі дані користувачів на пристроях клієнтів у <strong>переносному зашифрованому форматі бази даних</strong> &mdash; його можна передавати на інший пристрій.
 </p>
 <p>
     Зашифровані повідомлення від кінця до кінця тимчасово зберігаються на ретрансляційних серверах SimpleX до їх отримання, після чого вони назавжди видаляються.
@@ -1224,7 +1229,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Додаткова інформація</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1232,7 +1237,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Приховати інформацію</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1248,7 +1253,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">Ви власник мережі SimpleX</h3>
                             </div>
 
@@ -1259,7 +1264,7 @@ window.addEventListener('click',(e)=>{
     Мережа SimpleX повністю децентралізована та незалежна від будь-якої криптовалюти або будь-якої іншої мережі, окрім Інтернету.
 </p>
 <p>
-    Ви можете <strong>використовувати SimpleX з власними серверами</strong> або з серверами, які ми надаємо — і все одно підключатися до будь-якого користувача.
+    Ви можете <strong>використовувати SimpleX з власними серверами</strong> або з серверами, які ми надаємо &mdash; і все одно підключатися до будь-якого користувача.
 </p>
 
                                     </div>
@@ -1275,7 +1280,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Додаткова інформація</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="6" viewBox="0 0 10 6" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M1.50447 0.902966C1.21571 0.627397 0.747525 0.627397 0.458761 0.902966C0.169996 1.17853 0.169996 1.62532 0.458761 1.90089L4.21933 5.48961C4.25543 5.52406 4.29433 5.5542 4.33533 5.58003C4.62234 5.76088 5.01237 5.73074 5.26504 5.48961L9.02561 1.90089C9.31438 1.62532 9.31438 1.17853 9.02561 0.902966C8.73685 0.627397 8.26867 0.627397 7.97991 0.902966L4.74219 3.99273L1.50447 0.902966Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1283,7 +1288,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="underline text-[16px] tracking-[0.02em] underline-offset-4 text-primary-light dark:text-primary-dark">Приховати інформацію</span>
                                 <span class="flex items-center justify-center mt-1">
                                     <svg class="fill-primary-light dark:fill-primary-dark" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                                        <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                                     </svg>
                                 </span>
                             </a>
@@ -1323,7 +1328,7 @@ window.addEventListener('click',(e)=>{
     На відміну від інших мереж для обміну повідомленнями, у SimpleX <strong>немає ідентифікаторів, призначених користувачам</strong>. Він не покладається на номери телефонів, адреси на основі доменів (як електронна пошта або XMPP), імена користувачів, публічні ключі або навіть випадкові числа для ідентифікації своїх користувачів — оператори серверів SimpleX не знають, скільки людей використовують їхні сервери.
 </p>
 <p>
-    Для доставки повідомлень SimpleX використовує <a href="https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier">парні анонімні адреси</a> однобічних черг повідомлень, окремо для отриманих та відправлених повідомлень, зазвичай через різні сервери.
+    Для доставки повідомлень SimpleX використовує <a href='https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier'>парні анонімні адреси</a> однобічних черг повідомлень, окремо для отриманих та відправлених повідомлень, зазвичай через різні сервери.
 </p>
 <p>
     Цей дизайн захищає конфіденційність того, з ким ви спілкуєтесь, приховуючи це від серверів мережі SimpleX та від будь-яких спостерігачів. Щоб приховати вашу IP-адресу від серверів, ви можете <strong>підключатися до серверів SimpleX через Tor</strong>.
@@ -1344,7 +1349,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1383,7 +1388,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1410,7 +1415,7 @@ window.addEventListener('click',(e)=>{
     На відміну від федеративних мереж серверів (електронна пошта, XMPP або Matrix), сервери SimpleX не зберігають облікові записи користувачів, вони лише ретранслюють повідомлення, захищаючи приватність обох сторін.
 </p>
 <p>
-    Між надісланим і отриманим серверним трафіком немає спільних ідентифікаторів чи шифрованого тексту — якщо хтось його спостерігає, він не може легко визначити, хто спілкується з ким, навіть якщо TLS скомпрометовано.
+    Між надісланим і отриманим серверним трафіком немає спільних ідентифікаторів чи шифрованого тексту &mdash; якщо хтось його спостерігає, він не може легко визначити, хто спілкується з ким, навіть якщо TLS скомпрометовано.
 </p>
 
                         </div>
@@ -1428,7 +1433,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1440,7 +1445,7 @@ window.addEventListener('click',(e)=>{
     
     <div id="you-own-simplex-network" data-scroll-to="why-simplex" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
-            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Повністю децентралізована — користувачі володіють мережею SimpleX</h1>
+            <h1 class="text-3xl font-bold text-active-blue mb-6 ">Повністю децентралізована &mdash; користувачі володіють мережею SimpleX</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
                 
                     <div class="lg:max-w-[448px]">
@@ -1449,10 +1454,10 @@ window.addEventListener('click',(e)=>{
     Ви можете <strong>використовувати SimpleX зі своїми власними серверами</strong> і при цьому спілкуватися з людьми, які використовують сервери, попередньо налаштовані в додатках.
 </p>
 <p>
-    Мережа SimpleX використовує <a href="https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md" target="_blank">відкритий протокол</a> і надає <a href="https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript" target="_blank">SDK для створення чат-ботів</a>, що дозволяє реалізувати сервіси, з якими користувачі можуть взаємодіяти через додатки SimpleX Chat — ми справді чекаємо, щоб побачити, які сервіси SimpleX ви створите.
+    Мережа SimpleX використовує <a href='https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md' target='_blank'>відкритий протокол</a> і надає <a href='https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript' target='_blank'>SDK для створення чат-ботів</a>, що дозволяє реалізувати сервіси, з якими користувачі можуть взаємодіяти через додатки SimpleX Chat — ми справді чекаємо, щоб побачити, які сервіси SimpleX ви створите.
 </p>
 <p>
-    Якщо ви плануєте розробляти для мережі SimpleX, наприклад, чат-бота для користувачів додатка SimpleX або інтеграцію бібліотеки SimpleX Chat у ваші мобільні додатки, будь ласка, <a href="https://simplex.chat/contact#/?v=1&amp;smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D" target="_blank">зв'яжіться з нами</a> для отримання порад та підтримки.
+    Якщо ви плануєте розробляти для мережі SimpleX, наприклад, чат-бота для користувачів додатка SimpleX або інтеграцію бібліотеки SimpleX Chat у ваші мобільні додатки, будь ласка, <a href='https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D' target='_blank'>зв'яжіться з нами</a> для отримання порад та підтримки.
 </p>
 
                         </div>
@@ -1470,7 +1475,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -1501,66 +1506,66 @@ window.addEventListener('click',(e)=>{
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Повідомлення з шифруванням від кінця до кінця з можливістю використання Markdown та редагування</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Зображення, відео та файли з шифруванням від кінця до кінця</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Децентралізовані групи з шифруванням від кінця до кінця — тільки користувачі знають про їх існування</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Децентралізовані групи з шифруванням від кінця до кінця &mdash; тільки користувачі знають про їх існування</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-4.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-4-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Голосові повідомлення з шифруванням від кінця до кінця</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-5.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-5-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Зникнення повідомлень</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-6.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-6-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Дзвінки з шифруванням від кінця до кінця для аудіо та відео</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-7.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-7-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Переносне зашифроване зберігання додатку — переміщуйте профіль на інший пристрій</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Переносне зашифроване зберігання додатку &mdash; переміщуйте профіль на інший пристрій</p>
             </div>
             
             <div class="flex flex-col items-center">
                 <div class="bg-white flex items-center justify-center w-[175px] h-[110px] rounded-[20px] border-[#859096] border-solid border-[1px] shadow-[2px_2px_0px_#859096] dark:border-none dark:shadow-none mb-[20px] border-gradient">
-                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/feature-8.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/feature-8-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
-                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Режим інкогніто —<br>унікальний для SimpleX Chat</p>
+                <p class="text-grey-black dark:text-white text-[16px] font-medium text-center w-full max-w-[265px]">Режим інкогніто &mdash;<br>унікальний для SimpleX Chat</p>
             </div>
             
         </div>
@@ -1570,7 +1575,7 @@ window.addEventListener('click',(e)=>{
 
 <section id="privacy" class="bg-primary-bg-light dark:bg-primary-bg-dark py-[90px] overflow-hidden px-5 lg:h-[888px]">
     <div class="container scale-100">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Що робить SimpleX <span class="gradient-text">конфіденційним</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-20">Що робить SimpleX <span class='gradient-text'>конфіденційним</span></h2>
 
         <div class="swiper private-swiper overflow-hidden px-4 py-2">
             <div class="swiper-wrapper mb-16">
@@ -1578,8 +1583,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-10.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-10-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Тимчасові анонімні парні ідентифікатори</h3>
@@ -1596,8 +1601,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-6.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-6-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Позаканальний<br>обмін ключами</h3>
@@ -1614,8 +1619,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-1.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-1-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">2 рівні шифрування від кінця до кінця</h3>
@@ -1632,8 +1637,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-7.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-7-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Перевірка<br>цілісності повідомлення</h3>
@@ -1650,8 +1655,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-2.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-2-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Додатковий рівень<br>шифрування сервера</h3>
@@ -1666,14 +1671,14 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-8.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-8-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Змішування повідомлень<br>для зменшення кореляції</h3>
                         <div class="flex-1 py-3 flex flex-col gap-3">
                             
-                            <p class="text-grey-black dark:text-white text-[14px] text-center">Сервери SimpleX виступають як вузли низької затримки для змішування — вхідні та вихідні повідомлення мають різний порядок.</p>
+                            <p class="text-grey-black dark:text-white text-[14px] text-center">Сервери SimpleX виступають як вузли низької затримки для змішування &mdash; вхідні та вихідні повідомлення мають різний порядок.</p>
                             
                         </div>
                         <p class="text-grey-black dark:text-white text-[12px] text-center">Торкніться, щоб закрити</p>
@@ -1682,8 +1687,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-3.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-3-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Безпечний аутентифікований<br>транспорт TLS</h3>
@@ -1702,8 +1707,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-4.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-4-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Опційний<br>доступ через Tor</h3>
@@ -1720,8 +1725,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-9.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-9-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Однобічні<br>черги повідомлень</h3>
@@ -1738,8 +1743,8 @@ window.addEventListener('click',(e)=>{
                 
                 <div class="card swiper-slide relative h-[480px] rounded-[20px] bg-card-bg-light dark:bg-card-bg-dark border-[#859096] border-solid border-[1px] dark:border-none shadow-[2px_2px_0px_#859096] dark:shadow-none overflow-hidden">
                     <div class="flex items-center justify-center py-12 px-6 h-[322px]">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt="">
-                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt="">
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] dark:hidden" src="/img/new/private-5.svg" alt=""/>
+                        <img class="w-full max-w-[223px] h-full max-h-[226px] hidden dark:block" src="/img/new/private-5-dark.svg" alt=""/>
                     </div>
                     <div class="card-content flex flex-col items-center justify-between h-[138px] absolute bottom-0 py-6 px-6 bg-card-desc-bg-light dark:bg-card-desc-bg-dark rounded-b-[20px]">
                         <h3 class="text-grey-black dark:text-white text-[18px] my-4 font-bold leading-[26px] tracking-[0.01em] text-center">Кілька рівнів<br>наповнення вмісту</h3>
@@ -1774,14 +1779,14 @@ window.addEventListener('click',(e)=>{
 
 <section id="network" class="bg-secondary-bg-light dark:bg-secondary-bg-dark lg:h-[642px] py-[95px] px-5">
     <div class="container">
-        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class="gradient-text">Network</span></h2>
+        <h2 class="text-grey-black dark:text-white text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold mb-5">SimpleX <span class='gradient-text'>Network</span></h2>
         <p class="text-black dark:text-white text-[16px] font-normal text-center mb-16">SimpleX Chat надає найкращу конфіденційність, поєднуючи переваги P2P та федеративних мереж.</p>
 
         <div class="flex flex-col lg:flex-row justify-between gap-12 md:gap-14 lg:gap-16">
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-1.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-1-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">На відміну від мереж P2P</h3>
@@ -1789,7 +1794,7 @@ window.addEventListener('click',(e)=>{
                         Всі повідомлення відправляються через сервери, що забезпечує кращу конфіденційність метаданих та надійну асинхронну доставку повідомлень, уникаючи багатьох <a href="javascript:void(0)" data-show-overlay="comparison-with-p2p-protocols" class="open-overlay-btn">проблем P2P-мереж</a>.
                         
     
-    </p><div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
+    <div id="comparison-with-p2p-protocols" data-scroll-to="network" class="overlay hidden fixed top-0 left-0 bottom-0 right-0 before:absolute before:w-full before:h-full bg-transparent before:bg-secondary-bg-light dark:before:bg-primary-bg-dark before:opacity-90 items-center justify-center p-3 md:p-10 z-[10000]">
         <div class="overlay-card w-full md:w-fit md:max-w-[1276px] bg-white dark:bg-card-bg-dark opacity-100 h-full md:h-fit md:max-h-[660px] z-[10001] rounded-md shadow-[0px_3px_12px_rgba(0,0,0,0.2)] p-6 py-10 sm:p-14 overflow-auto scale-100">
             <h1 class="text-3xl font-bold text-active-blue mb-6 ">Порівняння з протоколами P2P-повідомлень</h1>
             <div class="flex flex-col-reverse lg:flex-row gap-10 justify-between">
@@ -1797,26 +1802,26 @@ window.addEventListener('click',(e)=>{
                     <div class="lg:max-w-[448px]">
                         <div class="text-grey-black dark:text-white flex flex-col gap-6 text-base">
                             <p>
-    <a href="https://en.wikipedia.org/wiki/Peer-to-peer">Протоколи та додатки для P2P-зв'язку</a> мають різні проблеми, які роблять їх менш надійними порівняно із SimpleX, складнішими для аналізу та вразливими до кількох типів атак.
+    <a href='https://en.wikipedia.org/wiki/Peer-to-peer'>Протоколи та додатки для P2P-зв'язку</a> мають різні проблеми, які роблять їх менш надійними порівняно із SimpleX, складнішими для аналізу та вразливими до кількох типів атак.
 </p>
 <ol style="list-style: auto; padding-left: 1em;">
     <li>
-        P2P-мережі покладаються на якусь варіацію <a href="https://en.wikipedia.org/wiki/Distributed_hash_table">розподіленої хеш-таблиці (DHT)</a> для маршрутизації повідомлень. Дизайни DHT повинні балансувати гарантію доставки та затримку. У SimpleX є як краща гарантія доставки, так і менша затримка порівняно із P2P, оскільки повідомлення може передаватися паралельно кількома серверами, використовуючи сервери, обрані отримувачем. У P2P-мережах повідомлення проходить через вузли <em>O(log N)</em> послідовно, використовуючи вузли, обрані алгоритмом.
+        P2P-мережі покладаються на якусь варіацію <a href='https://en.wikipedia.org/wiki/Distributed_hash_table'>розподіленої хеш-таблиці (DHT)</a> для маршрутизації повідомлень. Дизайни DHT повинні балансувати гарантію доставки та затримку. У SimpleX є як краща гарантія доставки, так і менша затримка порівняно із P2P, оскільки повідомлення може передаватися паралельно кількома серверами, використовуючи сервери, обрані отримувачем. У P2P-мережах повідомлення проходить через вузли <em>O(log N)</em> послідовно, використовуючи вузли, обрані алгоритмом.
     </li>
     <li>
         У дизайні SimpleX, на відміну від більшості P2P-мереж, немає жодних глобальних ідентифікаторів користувачів будь-якого виду, навіть тимчасових, та використовуються лише тимчасові парні ідентифікатори, що забезпечує кращу анонімність та захист метаданих.
     </li>
     <li>
-        P2P не вирішує проблему атаки <a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">MITM</a>, і більшість існуючих реалізацій не використовують поза каналом повідомлень для початкового обміну ключами. SimpleX використовує поза каналом повідомлень або, у деяких випадках, передбачені і безпечні з'єднання для початкового обміну ключами.
+        P2P не вирішує проблему атаки <a href='https://en.wikipedia.org/wiki/Man-in-the-middle_attack'>MITM</a>, і більшість існуючих реалізацій не використовують поза каналом повідомлень для початкового обміну ключами. SimpleX використовує поза каналом повідомлень або, у деяких випадках, передбачені і безпечні з'єднання для початкового обміну ключами.
     </li>
     <li>
-        Реалізації P2P можуть бути заблоковані деякими інтернет-провайдерами (наприклад, <a href="https://en.wikipedia.org/wiki/BitTorrent">BitTorrent</a>). SimpleX є незалежним від транспорту — він може працювати через стандартні веб-протоколи, наприклад, WebSockets.
+        Реалізації P2P можуть бути заблоковані деякими інтернет-провайдерами (наприклад, <a href='https://en.wikipedia.org/wiki/BitTorrent'>BitTorrent</a>). SimpleX є незалежним від транспорту — він може працювати через стандартні веб-протоколи, наприклад, WebSockets.
     </li>
     <li>
-        Всі відомі P2P-мережі можуть бути вразливими до атаки <a href="https://en.wikipedia.org/wiki/Sybil_attack">Sybil</a>, оскільки кожен вузол є відкритим, і мережа працює як ціле. Відомі заходи для пом'якшення цієї атаки вимагають або централізованого компонента, або дорогого <a href="https://en.wikipedia.org/wiki/Proof_of_work">доказу роботи</a>. Мережа SimpleX не має виявності сервера, вона роздроблена і працює як кілька ізольованих підмереж, що робить неможливими атаки на всю мережу.
+        Всі відомі P2P-мережі можуть бути вразливими до атаки <a href='https://en.wikipedia.org/wiki/Sybil_attack'>Sybil</a>, оскільки кожен вузол є відкритим, і мережа працює як ціле. Відомі заходи для пом'якшення цієї атаки вимагають або централізованого компонента, або дорогого <a href='https://en.wikipedia.org/wiki/Proof_of_work'>доказу роботи</a>. Мережа SimpleX не має виявності сервера, вона роздроблена і працює як кілька ізольованих підмереж, що робить неможливими атаки на всю мережу.
     </li>
     <li>
-        P2P-мережі можуть бути вразливими до атаки <a href="https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent">DRDoS</a>, коли клієнти можуть ребродкастити та збільшувати трафік, що призводить до відмови в обслуговуванні на рівні всієї мережі. Клієнти SimpleX лише пересилають трафік від відомого підключення і не можуть бути використані зловмисником для збільшення трафіку в усій мережі.
+        P2P-мережі можуть бути вразливими до атаки <a href='https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent'>DRDoS</a>, коли клієнти можуть ребродкастити та збільшувати трафік, що призводить до відмови в обслуговуванні на рівні всієї мережі. Клієнти SimpleX лише пересилають трафік від відомого підключення і не можуть бути використані зловмисником для збільшення трафіку в усій мережі.
     </li>
 </ol>
                         </div>
@@ -1834,12 +1839,12 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
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+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
 
-                    <p></p>
+                    </p>
                 </div>
             </div>
 
@@ -1847,8 +1852,8 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-2.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-2-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">На відміну від федеративних мереж</h3>
@@ -1862,13 +1867,13 @@ window.addEventListener('click',(e)=>{
 
             <div class="flex flex-col md:flex-row lg:flex-col items-center md:gap-9 lg:gap-0">
                 <div class="mb-4 md:mb-0 lg:mb-8 md:flex-[1] flex items-center justify-center">
-                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden">
-                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block">
+                    <img src="/img/new/network-3.svg" alt="" class="dark:hidden"/>
+                    <img src="/img/new/network-3-dark.svg" alt="" class="hidden dark:block"/>
                 </div>
                 <div class="md:flex-[2] flex flex-col items-center justify-center">
                     <h3 class="text-active-blue text-xl font-bold text-center md:text-left lg:text-center self-stretch">Мережа SimpleX</h3>
                     <p class="text-black dark:text-white text-base font-normal text-center md:text-left lg:text-center">
-                        сервери надають <span class="text-active-blue">однобічні черги</span> для з'єднання користувачів, але вони не мають видимості графа підключень в мережі — лише користувачі.
+                        сервери надають <span class='text-active-blue'>однобічні черги</span> для з'єднання користувачів, але вони не мають видимості графа підключень в мережі &mdash; лише користувачі.
                     </p>
                 </div>
             </div>
@@ -1925,7 +1930,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">1. Що відчувають користувачі</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-1.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Ви можете створювати контакти та групи і вести двосторонні розмови, як у будь-якому іншому месенджері.
                         </p>
@@ -1938,7 +1943,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">2. Як це працює</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-2.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Для кожного з'єднання ви використовуєте дві окремі черги обміну повідомленнями для відправки та отримання повідомлень через різні сервери.
                         </p>
@@ -1951,7 +1956,7 @@ window.addEventListener('click',(e)=>{
                 <div class="swiper-slide h-[inherit]">
                     <div class="tab-button p-2 text-[20px] text-center font-bold active md:hidden">3. Що бачать сервери</div>
                     <div class="flex flex-col justify-center items-center">
-                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="">
+                        <img class="h-[340px] mb-[74px] mt-[74px] md:hidden" src="/img/new/explained-3.svg" alt="" />
                         <p class="text-black dark:text-white text-[16px] font-normal text-center">
                             Сервери мають окремі анонімні облікові дані для кожної черги і не знають, які користувачі до них відносяться.
                         </p>
@@ -2052,8 +2057,8 @@ window.addEventListener("load", function () {
                     <tr>
                         <th></th>
                         <th class="flex items-center justify-center pb-4">
-                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png">
-                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png">
+                            <img class="h-[34px] dark:hidden" alt="simplex logo" src="/img/new/logo-light.png"/>
+                            <img class="h-[34px] hidden dark:block" alt="simplex logo" src="/img/new/logo-dark.png"/>
                         </th>
                         <th class="pb-4">Signal, великі платформи</th>
                         <th class="pb-4">XMPP, Matrix</th>
@@ -2136,10 +2141,12 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">Підпишіться, щоб отримувати наші оновлення</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="Введіть свою електронну адресу">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -2148,28 +2155,18 @@ window.addEventListener("load", function () {
 
         <p class="text-grey-black dark:text-white text-center mb-7">Отримати SimpleX <a href="/downloads">додаток для настільних комп'ютерів</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/uk/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/uk/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/uk/why.md b/uk/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/uk/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/uk/why/index.html b/uk/why/index.html
index 8fc4ae21e8..a2065e8288 100644
--- a/uk/why/index.html
+++ b/uk/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/uk/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/wefunder.md b/wefunder.md
new file mode 100644
index 0000000000..16264e195b
--- /dev/null
+++ b/wefunder.md
@@ -0,0 +1,195 @@
+# SimpleX Chat equity crowdfunding on Wefunder
+
+SimpleX Chat is conducting an equity crowdfunding offering under Regulation Crowdfunding through Wefunder Portal LLC: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat). The offering terms are on Wefunder, including its AI-readable profile: [wefunder.com/simplex.chat.ai.txt](https://wefunder.com/simplex.chat.ai.txt).
+
+This page reproduces the memo from the Wefunder page, for AI assistants that cannot read Wefunder.
+
+## Memo
+
+For most of human history, conversations were private by default, and the communities people built belonged to them. The internet made communication easier, but it also placed companies between people and the relationships they created. SimpleX exists to bring that privacy and ownership back to the people.
+
+### In short
+
+SimpleX is the first and the only messaging network without any user identifiers – no phone numbers or usernames, not even random numbers. No one, including the servers, can see who talks to whom.
+
+No paid marketing. Hundreds of community publications. Over 3 million downloads. About 600,000 monthly users. $650,000 user donations. Over 1,000 community servers. Three security audits by Trail of Bits, the last to be published.
+
+Why now? Accelerating surveillance and deplatforming, and the rise of AI agents may increase demand for identity-free messaging that no other network can provide.
+
+SimpleX is more than a messenger – it's an open platform others can build on. Developers already built moderation and AI bots, bridges, and other services. Every service may increase the value of the network and bring new people in.
+
+We plan to charge businesses and channels for public names, business messaging and paid servers beyond the free tier, while private messaging remains free.
+
+### Current perks for investors
+
+If you invest $500 or more, you will receive a free SimpleX public name for your channel or business – 8+ letters with $500+ investment, 7+ letters with $1,000+, and 6+ letters with $5,000+.
+
+The name will be registered for 5 years while early bird terms apply, and for 3 years after that.
+
+All investors receive free SimpleX supporter badges as perks. More details: [SimpleX Supporter Badges](https://simplex.chat/blog/20260919-simplex-supporter-badges.md).
+
+### Every other network can identify users
+
+For 150 years, all networks required user identifiers. From the telephone invented in the 19th century, to email services, social media, and messaging – using phone numbers, usernames, random IDs or public keys – before SimpleX Network, to be reachable, you had to be identifiable.
+
+#### Every other messenger knows who you talk to
+
+User identification gives networks power over users to surveil their private life, to sell their data, and to revoke access. Even encrypted platforms see who you talk to, when, and where. Pseudonyms don't help – your contacts are a fingerprint.
+
+And being identified puts your identity and data at risk of being used by criminals.
+
+#### Every other platform can censor users without due process
+
+Telegram blocked 44 million groups and channels in 2025 alone. YouTube creators lose channels and can't recover them even after winning in legal proceedings.
+
+Every platform that distributes content at scale identifies both the publisher and the audience – giving platform owners the power to censor public speech.
+
+Publishers and content creators build audiences on borrowed infrastructure. One policy change, and the audience that took years to build can be gone.
+
+The root cause of these problems is user identification. The solution is not better policies or stronger encryption with the same architecture – it is a different architecture, without user IDs.
+
+### We invented and built SimpleX Network without any user identifiers
+
+It uses no phone numbers, emails, or user accounts – to take power from the network and give it back to the users. The network runs on multiple independent operators – SimpleX Chat and Flux are preconfigured in the app, and anyone can run their own servers.
+
+And we built a free SimpleX Chat app, for mobile and desktop, that uses SimpleX Network to connect to other users.
+
+SimpleX Chat provides private messaging without any user IDs – it protects the users, because no one can see who they talk to. As one X user wrote: "As long as I don't invite anyone to a chat, nobody can find me – and that's the best part about it. That's how privacy works". And families tell us they use SimpleX Chat with their children, because they feel safe knowing no one can reach them.
+
+SimpleX Chat also enables public groups and channels, where owners fully control them, and nobody can take their work, because only the users hold the keys.
+
+Every conversation in SimpleX Chat has its own network address, removing the need for any user IDs on the network. There is no user data on the servers that could be breached or sold – all user data exists only on user devices.
+
+SimpleX software is open-source and based on open protocols. It was audited by Trail of Bits in 2022, 2024, and 2026 (will be published soon).
+
+### 600,000+ users – organic growth
+
+Over 600,000 people use SimpleX Chat every month – up roughly 70% in the last six months – and all of them found it without any paid marketing. Among them are security and cryptography experts – the hardest users to win over.
+
+200+ independent reviews, posts, and videos in 20+ languages ([simplex.chat/links](https://simplex.chat/links.md)).
+
+3 million people have downloaded the app.
+
+Users send over 20 million messages a day via pre-configured servers.
+
+Users have donated over $650,000 (including the donation from Vitalik Buterin), paying for something they could use for free.
+
+All of it was built on a total investment of just $1.7M.
+
+### SimpleX is a network, not just an app
+
+Not only the people who use SimpleX primarily for private messaging, but also four other kinds of participants came to the network:
+
+- Creators, with thousands of public groups and channels.
+- Businesses: 50+ support customers over SimpleX.
+- Developers: 19K+ GitHub stars, 1,400+ forks.
+- Operators: ~1,000 servers run by volunteers at their own cost, plus Flux and StormyCloud.
+
+Each user group makes the network more valuable to the rest – more users attract creators and businesses, creators attract servers and developers, more content and network utility attracts more users – driving organic growth.
+
+### Channels accelerate SimpleX Network growth
+
+Messaging grows person-by-person: whole social graphs have to move together, which is slow against widely used networks, such as WhatsApp or Telegram. Channels accelerate it – one creator who brings a channel to SimpleX can bring thousands of subscribers, some of whom would then create their own channels.
+
+Users have created over 12,500 scalable channels in the five months since they shipped. 500+ public groups and channels are in the curated directory, 30% of them are active daily. Telegram channels tried to migrate in 2024/25, before SimpleX channels could scale. All that growth happened without in-app discovery of groups and channels – we are planning to release it this year, to further accelerate the growth.
+
+Each channel can also be published on the open web – like [simplex.chat/news](https://simplex.chat/news). Search engines index these pages, and anyone can read them in a browser without installing the SimpleX Chat app, so a channel can reach more people than use the app, and some of them may install it.
+
+### Developers already bet on SimpleX success
+
+Developers have already started building on SimpleX Network, with some projects defining themselves as SimpleX-first – they run all communications of their applications over the SimpleX Network. They built moderation, swap, and AI bots, bridges (Telegram/Matterbridge), a public server registry, and the OpenClaw plugin. To enable their work, we provide the JavaScript and Python libraries, a customer-support bot for businesses, and binaries to self-host servers.
+
+Every service developers build on SimpleX Network may increase its value, and bring new users to SimpleX Chat. In 2027, we are planning to release secure chat widgets and activities – to accelerate community innovation, by allowing custom UI for bots and services right in the conversation.
+
+### Why SimpleX cannot be copied
+
+No other communication system combines participation privacy, sovereign ownership, infrastructure independence, and scalable one-to-many delivery:
+
+| Property | Telegram | Nostr | Signal | Matrix | Mastodon | **SimpleX** |
+|---|---|---|---|---|---|---|
+| Content visible to operator | Yes | Yes | No | Configurable | Yes | **Yes** |
+| Participant identity visible to operator | Yes | Yes | Yes | Yes | Yes | **No** |
+| Channel identity independent of infrastructure | No | Yes | No | No | No | **Yes** |
+| Sovereign ownership (no 3rd party can seize) | No | Yes | No | No | No | **Yes** |
+| Programmable governance | No | No | No | No | No | **Planned** |
+| Cryptographic content deniability | No | No | Yes | Yes | No | **Yes (default)** |
+| Scalable one-to-many delivery | Yes | Yes | No | Limited | Yes | **Yes** |
+
+Of these networks, only SimpleX can protect participants' privacy, because it would require other networks to remove user identifiers – not adding a feature to an existing system but designing a different one. That is hard for three reasons, each stopping a different kind of competitor.
+
+Technically. Other networks rely on user IDs to route messages between users. Signal, Session, Matrix, and Nostr cannot simply drop IDs – they would have to rebuild from scratch.
+
+Economically. Large platforms monetize user identifiers: Telegram and Meta earn from ads and data, and that requires linking every action and connection to a single user ID. Removing IDs would destroy their revenue model. A large company is highly unlikely to do that.
+
+Cold start. A new company could build a no-ID network from scratch. But a network needs users, creators, businesses, developers, and servers, all at the same time. A newcomer would have to achieve it from zero, while competing with the SimpleX Network.
+
+### Why now: three trends that may grow SimpleX
+
+Growing surveillance of private life. Big centralized platforms are keen to scan private messages to train their AI models, supported by proposed laws. More people would move to use private messaging that keeps no record of who they talk to.
+
+Accelerating deplatforming. More and more creators are removed from centralized platforms, without any due process. An audience built over years can disappear with one policy change. Affected or at risk content creators would use decentralized networks where they own their work.
+
+AI agents acting for people. A growing number of AI agents are beginning to handle logins and money on behalf of people. If a platform controls an agent's identity, the platform can shut the agent down or turn it against the person it works for. User-controlled IDs are a basic security for the agentic Internet, not a preference.
+
+All three trends increase the demand for identity-free messaging. No other existing network can provide it.
+
+### Revenue plan: free for users, channels & businesses pay
+
+Private messaging should remain free for the users. While additional storage and transfer capacity may be paid, charging users for features would erode the trust that helps the network grow organically. Instead, we plan to earn from the infrastructure and services that channels and businesses need. On average, users donated ~$1.24 each per year, which shows they are willing to pay before any paid features exist.
+
+#### Public network names
+
+Most users want to be reachable only by people they choose. But businesses, creators, and publishers need to be found, so they need a public name they control. Even with a public name, the network cannot see who they talk to.
+
+SimpleX public names are globally unique names for a public channel or business, paid yearly and controlled by the owner's key, so no one can seize it. The public test is already released; sales are planned in 3–6 months. Pricing is based on name length. SimpleX Chat plans to earn approximately 80-90% of namespace revenue. At an average expected price of $50 a year (to be confirmed) for a name, 10,000 registered names would cover our current $360,000 annual operating cost.
+
+If you invest $500 or more in this community round, you would receive a name as a perk, registered for 5 years during early bird terms and for 3 years after that, when the names launch.
+
+#### Business messaging
+
+We are developing a web widget that would add encrypted chat to any website with one line of code, allowing visitors to talk to the business in their browser without installing anything. It is built for privacy-first businesses and business sectors where anonymity is legally required: whistleblowing, ethics, HR, security, legal, sensitive customers, sources, and tip lines.
+
+50+ businesses use SimpleX Chat for support, and they would be the first customers. The proof-of-concept is done; planned in 6–9 months from closing the round, with an expected price of $20–100/month per business.
+
+It grows the network as well. Someone who talks to a few businesses is already using SimpleX without having installed it, and a QR code scan would bring those conversations into the app.
+
+#### Paid servers for big channels
+
+Big public channels that have grown beyond the free tier would pay for the servers that deliver their messages. The proof-of-concept is ready, planned within 12 months of closing the community round, with an expected price of $20–50/month, depending on the channel size. We plan that server operators would earn up to 65% of the revenue, several times their cost, and SimpleX Chat earns the rest.
+
+### An open network others can build on
+
+The network is open, and it would help if other developers built their own apps on it – one app cannot reach every audience, and many apps may grow the network faster than we could alone. A bigger network may also bring more users and revenue for SimpleX Chat.
+
+The SimpleX Network Consortium, an agreement between a non-profit SimpleX Network Foundation and SimpleX Chat, prevents any single company from controlling the network. The protocol and the right to use the SimpleX mark for the network are licensed to the foundation permanently, so that operators and users can trust that the network protocols and software remain available regardless of who owns the company.
+
+SimpleX Chat business is protected too: the company owns the app, the brand, mobile application store distribution, preset relay infrastructure, and will retain its revenue share from the infrastructure payments, a position protected by its veto power over Consortium decisions.
+
+### The goal: the universal private transport layer
+
+Every network before messaging converged to one protocol – telephony, email, the web. Messaging is the exception, because each app's experience can't reduce to a shared protocol. Once we add custom user experiences in the chat, SimpleX might become the network messaging converges on.
+
+The planned revenue above is the first layer. The same network and protocol can deliver: private messages, public channels, businesses, and traffic between AI agents. The optional directory and payment system would create revenue for the server operators and SimpleX Chat.
+
+AI agents are the next layer, and developers already build AI bots. The network does not distinguish between a person and an agent. Agents need exactly what SimpleX provides: an identity no platform controls, and communication no one can observe.
+
+The same public names and payment system can be used by any service on the network, not only messaging or channels, so the revenue may grow with everything built on it.
+
+### Why this team wins
+
+We have worked on publishing, messaging, protocol design, blockchains, and cryptography. We have built large-scale systems and open-source software that millions of systems and projects rely on.
+
+We believe that what SimpleX Network achieved comes from listening to users' criticism. Unlike most technology startups, we announce our plans in advance, and change them before they become products, saving time and resources to get to product-market fit.
+
+We are also fortunate to have great advisors. Some of them are: Moritz Angermann (IOHK, Haskell compiler core contributor), Bruce McCarthy (Product Culture founder), Tom Ritter (Tor, Mozilla, an expert in secure protocol design), and Nick Rogers (ex-CPTO of Stream, an expert in agentic products). Three of them invested in this round.
+
+### Invest in SimpleX Chat
+
+By investing in SimpleX Chat, you benefit from the company growth. You also help build the first network that protects private life because it has no user identifiers – a design decision that cannot be retrofitted into any existing network.
+
+We are building a network that people own. Businesses, creators, and publishers keep the audiences and communities they build, and no company can take them away or unilaterally shut them down. All users can talk, read, and buy without being watched or tracked from one site to the next. None of this is new. Before the Internet, people's conversations were private, and the groups and audiences they built were their own, with no company in the middle. We lost that when we moved online, and we need it back – the future we set out in our [network philosophy](https://simplex.chat/why.md).
+
+We're building the network to support that future. We invite you to own a part of it: [wefunder.com/simplex.chat](https://wefunder.com/simplex.chat).
+
+This Regulation Crowdfunding offering is made available through Wefunder Portal LLC. This investment involves a high degree of risk, including the possible loss of your investment.
+
diff --git a/why.md b/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/why/index.html b/why/index.html
index d07088c007..cc3cd2cc2b 100644
--- a/why/index.html
+++ b/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/zh_Hans/contact.md b/zh_Hans/contact.md
new file mode 100644
index 0000000000..60ead54d44
--- /dev/null
+++ b/zh_Hans/contact.md
@@ -0,0 +1,65 @@
+# 您收到了一个用于连接 SimpleX Chat 的地址
+
+## 使用手机或平板电脑上的 SimpleX Chat 应用程序扫描二维码。
+
+当您查看此页面时，此链接中的公钥和消息队列地址不会通过网络发送 ——它们包含在链接 URL 的哈希片段中。
+
+还没有下载 SimpleX Chat 吗？
+
+使用下面的链接下载应用程序。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+从移动应用程序扫描二维码
+
+# 您收到了一个用于连接 SimpleX Chat 的地址
+
+要建立连接：
+
+安装 SimpleX 应用程序
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid)
+
+1
+
+在应用程序中连接
+
+打开 SimpleX 应用程序
+
+2
+
+点按应用中的 “连接” 按钮
+
+3
+
+## 使用 SimpleX Chat 应用程序扫描二维码
+
+当您查看此页面时，此链接中的公钥和消息队列地址不会通过网络发送 ——它们包含在链接 URL 的哈希片段中。
+
+## 将 SimpleX 聊天安装到终端
+
+使用此命令：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+查看 SimpleX 聊天 GitHub 仓库 如何下载或从源代码下载进行编译的说明。
+
+---
+
+## 如果您已经为终端安装了 SimpleX Chat
+
+如果您已经安装 用于终端的 SimpleX Chat v1.0.0+, 复制下面的命令并在聊天中使用它：
+
+## 加入 SimpleX
+
+我们邀请您加入对话
+
+[加入 REDDIT 社区](https://www.reddit.com/r/SimpleXChat/) [在 GitHub 上加入我们](https://github.com/simplex-chat) [在这里捐款来帮助我们](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+注册以接收我们的更新
+
+---
+
+获取 SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid)
diff --git a/zh_Hans/contact/index.html b/zh_Hans/contact/index.html
index 7194ff338d..ad8b9b7ae8 100644
--- a/zh_Hans/contact/index.html
+++ b/zh_Hans/contact/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">您收到了一个用于连接 SimpleX Chat 的地址</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">使用下面的链接下载应用程序。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">安装 SimpleX 应用程序</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">使用 SimpleX Chat 应用程序扫描二维码</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">将 SimpleX 聊天安装到终端</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub 仓库</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
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+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
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                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">如果您已经为终端安装了 SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">注册以接收我们的更新</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="输入您的电子邮箱地址">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">获取 SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/fdroid.md b/zh_Hans/fdroid.md
new file mode 100644
index 0000000000..49c29626d9
--- /dev/null
+++ b/zh_Hans/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## 通过 F-Droid 下载 SimpleX
+
+### SimpleX 存储库
+
+开发人员构建的稳定版和测试版
+
+要将其添加到您的 F-Droid 客户端，请扫描二维码或使用以下 URL：
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+签名密钥指纹 (SHA-256):
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org 存储库
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+由 F-Droid.org 构建的稳定版本
+
+此存储库的版本将延迟数天发布.
+
+SimpleX Chat 和 F-Droid.org 存储库使用不同的密钥对构建进行签名。 如需切换，请[导出](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device)聊天数据库并重新安装应用。
diff --git a/zh_Hans/fdroid/index.html b/zh_Hans/fdroid/index.html
index 599e195a1d..1b1f8af88e 100644
--- a/zh_Hans/fdroid/index.html
+++ b/zh_Hans/fdroid/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,7 +683,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -690,7 +695,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">通过 F-Droid 下载 SimpleX</h2>
 
@@ -702,15 +707,16 @@ window.addEventListener('click',(e)=>{
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">开发人员构建的稳定版和测试版</p>
                         <p>要将其添加到您的 F-Droid 客户端，请<span class="hide-on-mobile">扫描二维码或</span>使用以下 URL：</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             签名密钥指纹 (SHA-256):
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -721,7 +727,7 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org 存储库</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">由 F-Droid.org 构建的稳定版本</p>
                 <p class="mb-2">此存储库的版本将延迟数天发布.</p>
                 <p class="mb-2">SimpleX Chat 和 F-Droid.org 存储库使用不同的密钥对构建进行签名。 如需切换，请<a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">导出</a>聊天数据库并重新安装应用。</p>
@@ -729,17 +735,7 @@ window.addEventListener('click',(e)=>{
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/file.md b/zh_Hans/file.md
new file mode 100644
index 0000000000..503e7a29d3
--- /dev/null
+++ b/zh_Hans/file.md
@@ -0,0 +1,31 @@
+# SimpleX 文件传输
+
+将文件拖放到此处
+
+或
+
+选择文件
+
+最大 100 MB - [SimpleX Chat 应用](https://simplex.chat/downloads) 支持最大 1 GB 文件
+
+使用端到端加密安全发送文件——无需注册账户，不会追踪。
+
+## 获取 SimpleX Chat——最安全、最私密的即时通讯工具
+
+您刚才使用的文件传输功能与 SimpleX Chat 使用相同的数据路由协议。该应用提供端到端加密的消息传递、语音和视频通话、群组功能以及文件发送功能。无需注册账号，无需电话号码，无需邮箱，也无需用户个人资料 ID。
+
+# XFTP协议：最安全的文件传输协议
+
+### 无需注册账号
+
+每个文件片段都使用一个新的随机密钥。数据路由器没有“用户”或“文件”的概念——它们传输的是固定大小的加密文件片段。
+
+### 浏览器中采用三重加密
+
+文件加密密钥仅存在于 URL 哈希片段中——您的浏览器绝不会将其发送给服务器。加密过程包含三层：TLS 传输层、每个接收者加密层（每次传输使用唯一的临时密钥）以及文件端到端加密层。
+
+### 独立数据路由器
+
+文件被分割成多个片段后，会通过独立运营商运营的网络路由器进行传输。任何运营商都无法看到文件的实际大小或名称。即使路由器遭到入侵，也只能看到固定大小的加密片段。网络路由器会将文件片段缓存约48小时。
+
+[阅读 XFTP 协议规范 →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/zh_Hans/file/index.html b/zh_Hans/file/index.html
index 1e58b201a5..44f79a869b 100644
--- a/zh_Hans/file/index.html
+++ b/zh_Hans/file/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -478,7 +482,10 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><link rel="stylesheet" href="/file-assets/index.css">
+        
+
+
+<link rel="stylesheet" href="/file-assets/index.css">
 <style>
   /* Reset website .card styles that conflict with xftp bundle */
   #app .card { cursor: default; }
@@ -650,7 +657,7 @@ window.addEventListener('click',(e)=>{
 
 </style>
 
-</head><body><section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
+<section class="bg-secondary-bg-light dark:bg-primary-bg-dark py-10 mt-[66px] px-5">
   <div class="container flex flex-col items-center mx-auto">
     <noscript>
       <p class="text-center text-grey-black dark:text-white py-10">
@@ -658,7 +665,7 @@ window.addEventListener('click',(e)=>{
       </p>
     </noscript>
     <h1 class="text-[38px] text-center font-bold text-active-blue mb-8">SimpleX 文件传输</h1>
-    <div id="app" data-xftp-app="" data-no-hashchange="" class="w-full">
+    <div id="app" data-xftp-app data-no-hashchange class="w-full">
       <div class="card">
         <div class="drop-zone">
           <p>将文件拖放到此处</p>
@@ -699,11 +706,11 @@ window.addEventListener('click',(e)=>{
       您刚才使用的文件传输功能与 SimpleX Chat 使用相同的数据路由协议。该应用提供端到端加密的消息传递、语音和视频通话、群组功能以及文件发送功能。无需注册账号，无需电话号码，无需邮箱，也无需用户个人资料 ID。
     </p>
     <div class="flex items-center justify-center gap-4 flex-wrap">
-      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-      <a href="/zh_Hans/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+      <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+      <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+      <a href="/zh_Hans/fdroid"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+      <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+      <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
     </div>
   </div>
 </section>
@@ -751,7 +758,7 @@ window.addEventListener('click',(e)=>{
             </div>
 
             <svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg">
-                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"></path>
+                <path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.839522 -0.070157 0.427909 -0.059127 0.18094 0.207531C-0.0660305 0.474191 -0.0552645 0.895911 0.205003 1.14894L5.70862 6.49833L0.20247 11.851C-0.0577975 12.104 -0.0685635 12.5257 0.178407 12.7924C0.306324 12.9306 0.477936 13 0.650181 13C0.811033 13 0.971873 12.9397 1.09726 12.817L6.65343 7.41639L11.9025 12.5186C12.0285 12.6406 12.1893 12.7015 12.3495 12.7015C12.5218 12.7015 12.6934 12.6321 12.8213 12.4939C13.0689 12.2273 13.0582 11.8062 12.7973 11.5525Z"/>
             </svg>
         </div>
     </div>
@@ -830,17 +837,7 @@ window.addEventListener('click',(e)=>{
   }
 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/index.html b/zh_Hans/index.html
index 4cf9f077f0..fce0671c5b 100644
--- a/zh_Hans/index.html
+++ b/zh_Hans/index.html
@@ -62,6 +62,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/zh_Hans/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -781,11 +785,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/zh_Hans/fdroid" title="SimpleX 安卓应用（通过 F-Droid）"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS 测试版已在 TestFlight 上发布"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS 测试版已在 TestFlight 上发布" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="安全审计" href="https://www.trailofbits.com/about" target="_blank">
@@ -860,7 +864,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">现在</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">2027年6月</span>
diff --git a/zh_Hans/index.md b/zh_Hans/index.md
new file mode 100644
index 0000000000..b75e0f1da7
--- /dev/null
+++ b/zh_Hans/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# 变得 自由
+
+## 在属于你的网络中
+
+首个无用户 ID 的网络。
+您的联系人、群组和频道由您掌控。
+
+Invest in SimpleX Chat. [了解更多.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX 安卓应用（通过 F-Droid）](https://simplex.chat/zh_Hans/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[安全审计](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+安全
+审计
+
+[隐私指南通讯推荐](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix通讯推荐](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online出版物](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Mike Kuketz 的评论](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut播客访谈](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## 没人能看到您与谁交谈
+
+即使服务器也无法查看 – 所有消息看起来都像随机噪声。
+
+每天数千万条消息被私密送达。
+
+[了解更多关于 SimpleX 消息传递的知识](https://simplex.chat/zh_Hans/messaging)
+
+## 网络 由您掌控
+
+每个联系人和群组都在您的设备上，而非服务器数据库中。
+
+没有任何单一实体控制网络 – 任何人都可以运行服务器。
+
+[我们为什么要建造它](https://simplex.chat/zh_Hans/why)
+
+## 由用户资助
+
+为保持独立性，大型频道和社区将为其服务器付费。
+
+用户现在可以投资 SimpleX Chat — 众筹已上线！
+
+[投资 SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX 通往自由互联网的路线图
+
+2026
+
+: 扩展到大型社区
+
+逃离中心化平台
+
+2027年6月
+
+: 可持续社区与服务器
+
+推出 Community Credits
+
+2027年12月
+
+: 促进社区发展
+
+用于推广社区的工具
+
+[SimpleX 用户群组](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## 加入 SimpleX 社区
+
+超过 200 万人下载了 SimpleX 应用。
+
+在目录中找到您的频道和社区，并创建您自己的！
+
+[查看 SimpleX 目录](https://simplex.chat/directory)
diff --git a/zh_Hans/invitation.md b/zh_Hans/invitation.md
new file mode 100644
index 0000000000..89a4b57084
--- /dev/null
+++ b/zh_Hans/invitation.md
@@ -0,0 +1,65 @@
+# 您收到了一个连接 SimpleX Chat 的一次性链接
+
+## 使用手机或平板电脑上的 SimpleX Chat 应用程序扫描二维码。
+
+当您查看此页面时，此链接中的公钥和消息队列地址不会通过网络发送 ——它们包含在链接 URL 的哈希片段中。
+
+还没有下载 SimpleX Chat 吗？
+
+使用下面的链接下载应用程序。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+从移动应用程序扫描二维码
+
+# 您收到了一个连接 SimpleX Chat 的一次性链接
+
+要建立连接：
+
+安装 SimpleX 应用程序
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid)
+
+1
+
+在应用程序中连接
+
+打开 SimpleX 应用程序
+
+2
+
+点按应用中的 “连接” 按钮
+
+3
+
+## 使用 SimpleX Chat 应用程序扫描二维码
+
+当您查看此页面时，此链接中的公钥和消息队列地址不会通过网络发送 ——它们包含在链接 URL 的哈希片段中。
+
+## 将 SimpleX 聊天安装到终端
+
+使用此命令：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+查看 SimpleX 聊天 GitHub 仓库 如何下载或从源代码下载进行编译的说明。
+
+---
+
+## 如果您已经为终端安装了 SimpleX Chat
+
+如果您已经安装 用于终端的 SimpleX Chat v1.0.0+, 复制下面的命令并在聊天中使用它：
+
+## 加入 SimpleX
+
+我们邀请您加入对话
+
+[加入 REDDIT 社区](https://www.reddit.com/r/SimpleXChat/) [在 GitHub 上加入我们](https://github.com/simplex-chat) [在这里捐款来帮助我们](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+注册以接收我们的更新
+
+---
+
+获取 SimpleX [desktop app](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hans/fdroid)
diff --git a/zh_Hans/invitation/index.html b/zh_Hans/invitation/index.html
index ca1f4d1a66..f502d39525 100644
--- a/zh_Hans/invitation/index.html
+++ b/zh_Hans/invitation/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,12 +683,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">您收到了一个连接 SimpleX Chat 的一次性链接</h1>
@@ -696,11 +703,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">使用下面的链接下载应用程序。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -733,9 +740,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">安装 SimpleX 应用程序</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -778,7 +785,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">使用 SimpleX Chat 应用程序扫描二维码</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -798,7 +805,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">将 SimpleX 聊天安装到终端</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -815,7 +822,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub 仓库</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -829,7 +836,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">如果您已经为终端安装了 SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -866,10 +873,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">注册以接收我们的更新</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="输入您的电子邮箱地址">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -878,11 +887,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">获取 SimpleX <a href="/downloads">desktop app</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/zh_Hans/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/zh_Hans/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -891,17 +900,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/messaging.md b/zh_Hans/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## 为什么 SimpleX 是独特的
+
+### 您有完整的隐私
+
+SimpleX 保护您的个人资料、联系人和元数据的隐私，不让 SimpleX 网络服务器和任何观察者看到它们。
+
+与任何其他现有的消息传递网络不同，SimpleX 没有分配给用户的标识符—— **甚至随机数也没有**。
+
+### 您可以免受垃圾消息和平台滥用的侵害
+
+因为您在 SimpleX 网络上没有标识符或固定地址，所以除非您以二维码或链接的形式分享一次性或临时用户地址，没有人可以联系您。
+
+### 您控制您的数据
+
+SimpleX 以**便携式加密数据库格式**将所有用户数据存储在客户端设备上—— 它可以转移到另一个设备。
+
+端到端加密的消息在被收到前会暂时保存在 SimpleX 中继服务器上，传送完成后它们会被永久删除。
+
+### 您拥有 SimpleX 网络
+
+SimpleX 网络是完全去中心化的，并且独立于任何加密货币或除互联网以外的任何其他网络。
+
+您可以**搭配自己的服务器来使用 SimpleX**  或使用我们提供的服务器 — 并仍然连接到任何用户。
+
+# 您的身份、个人资料、联系人和元数据的完整隐私
+
+与其他消息网络不同，SimpleX **没有分配给用户的标识符**。 它不依赖电话号码、基于域的地址（如电子邮件或 XMPP）、用户名、公钥甚至随机数来识别其用户—— SimpleX 服务器运营方不知道有多少人使用其服务器。
+
+为了传递消息，SimpleX 使用单向消息队列的[成对匿名地址](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier)，通常通过不同的服务器将接收和发送的消息分开。
+
+这种设计保护了您正在与之通信的人的隐私，将其隐藏在 SimpleX 网络的服务器和任何观察者之外。 要对服务器隐藏您的 IP 地址，您可以**通过 Tor 连接到 SimpleX 服务器**。
+
+# 防止垃圾消息和平台滥用的最佳保护
+
+因为您在 SimpleX 网络上没有标识符，所以除非您以二维码或链接的形式分享一次性或临时用户地址，没有人可以联系您。
+
+即使使用可选的用户地址，当它被用于发送垃圾邮件联系请求，您可以更改或完全删除它而不会丢失任何连接。
+
+# 您数据的所有权、控制权和安全性
+
+SimpleX Chat 使用**便携式加密数据库格式**仅将所有用户数据存储在客户端设备上，该格式可以导出并传输到任何支持的设备。
+
+端到端加密的消息在被收到前会暂时保存在 SimpleX 中继服务器上，传送完成后它们会被永久删除。
+
+与联合网络服务器（电子邮件、XMPP 或 Matrix）不同，SimpleX 服务器不存储用户帐户，它们仅中继消息，保护双方的隐私。
+
+发送和接收的服务器流量之间没有共同的标识符或密文—— 如果有人在观察它，他们也无法轻易确定谁与谁通信，即使 TLS 受到威胁。
+
+# 完全去中心化 —— 用户拥有 SimpleX 网络
+
+您可以**将 SimpleX 与您自己的服务器一起使用**，并且仍然可以与使用应用中预配置服务器的人们进行通信。
+
+SimpleX 网络使用[开放协议](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md)并提供[用于创建聊天机器人的 SDK](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript)， 允许用户实现通过 SimpleX Chat 应用程序与之交互的服务—我们真的很期待看到您会依托SimpleX构建哪些服务。
+
+如果您正在考虑为在SimpleX 网络上开发，例如，为 SimpleX 应用程序用户开发聊天机器人，或将 SimpleX 聊天库集成到您的移动应用，请 [联系我们](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D)获取建议和支持。
+
+## 功能
+
+端到端加密的文字消息，支持markdown和编辑
+
+端到端加密的
+图片、视频和文件
+
+端到端加密的去中心化的秘密群组 —只有用户知道它们的存在
+
+端到端加密的语音消息
+
+支持消息自动销毁
+
+端到端加密的音视频通话
+
+便携的加密应用存储— 可将您的个人资料移至另一台设备
+
+隐身模式 —
+SimpleX Chat 独有
+
+## 是什么让 SimpleX 能够保密
+
+### 临时匿名成对标识符
+
+SimpleX 为每个用户的联系人或群组成员均使用临时匿名成对地址和凭据。
+
+它让消息能在没有用户标识符的情况下传递，并提供比替代方案更好的元数据隐私。
+
+### 带外密钥交换
+
+许多通信平台容易受到服务器或网络提供商的中间人攻击。
+
+为防止这种情况，当您将通讯地址作为链接或二维码共享时，SimpleX 应用程序会在带外传递一次性密钥。
+
+### 双层端到端加密
+
+双棘轮协议——具有完美前向保密和入侵恢复功能的 OTR(不留记录即时通讯) 消息传递。
+
+每个队列中的网络与密码学库加密盒(NaCL cryptobox)可防止 TLS 受到威胁时消息队列之间的流量关联。
+
+### 消息完整性验证
+
+为了保证消息完整性，消息按顺序编号并会包含前一条消息的哈希值。
+
+如果添加、删除或更改任何消息，收件人都会收到警告。
+
+### 服务器提供的另一层加密
+
+为来信附加服务器加密层，以防止在 TLS 受破坏时接收和发送的服务器流量之间发生关联。
+
+### 通过消息混合减少相关性
+
+SimpleX 服务器会充当低延迟混合节点，打乱传入和传出消息的顺序。
+
+### 安全认证的TLS传输
+
+客户端与服务器之间的连接只使用强加密的 TLS 1.2/1.3。
+
+服务器指纹和通道绑定可防止中间人与重放攻击。
+
+禁用连接恢复以防止会话攻击。
+
+### 可选择通过 Tor 访问
+
+为了保护您的 IP 地址，您可以通过 Tor 或其他传输覆盖网络访问服务器。
+
+要通过 Tor 使用 SimpleX，请安装 [Orbot](https://guardianproject.info/apps/org.torproject.android/) 应用并启用 SOCKS5 代理（在 [iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)上需要使用 VPN 模式）。
+
+### 单向消息队列
+
+每个消息队列都有不同的发送和接收地址，单向地传递消息。
+
+与传统的消息代理相比，它减少了攻击媒介和可用的元数据。
+
+### 多层级的内容填充
+
+SimpleX 为每个加密层进行内容填充来对抗长度扩展攻击。
+
+它使不同大小的消息在服务器和网络监视者看来是一样的。
+
+## SimpleX 网络
+
+SimpleX Chat 通过结合 P2P 和联邦网络的优势使其保密性无与伦比。
+
+### 与 P2P 网络不同
+
+所有消息都通过服务器发送，既能更好地保护元数据隐私和可靠地传递异步消息，同时也能避免许多 .
+
+# 与 P2P 通讯协议的比较
+
+[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) 消息传递协议和应用程序存在各种问题，使得它们不如 SimpleX 可靠，分析起来更复杂，并且 容易受到多种类型的攻击。
+
+1. P2P 网络依赖于[分布式散列表(DHT)](https://en.wikipedia.org/wiki/Distributed_hash_table) 的某些变体来路由消息。 DHT 在设计上必须平衡可达性和延迟。 SimpleX 比 P2P 具有更好的可达性和更低的延迟，因为消息可以通过通讯双方选择的多个服务器并行地冗余传递。若是在 P2P 网络中，消息则需要使用算法选择，并依次通过 *O(log N)* 个节点。
+2. 与大多数 P2P 网络不同，SimpleX 在设计上没有任何类型的全局用户标识符，甚至临时的也没有。SimpleX 仅使用临时的成对标识符，提供更好的匿名性和元数据保护。
+3. P2P 并未解决[中间人攻击(MITM Attack)](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) 问题。大多数现有的 P2P 实现没有使用带外通讯来进行初始密钥的交换，而 SimpleX 使用带外通讯，或者在某些情况下，使用预先存在的安全和可信连接来进行初始密钥交换。
+4. P2P 实现（如[BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)）可能会被某些互联网提供商阻止。 SimpleX 与传输协议无关 — 它可以在标准网络协议上工作，例如 WebSockets。
+5. 所有已知的 P2P 网络都可能受到[Sybil 攻击](https://en.wikipedia.org/wiki/Sybil_attack)，因为每个节点都是可发现的，并且网络作为一个整体运行。 已知的缓解措施不是需要一个中心化的组件就是需要昂贵的[工作量证明](https://en.wikipedia.org/wiki/Proof_of_work)。而 SimpleX 网络没有服务器可发现性，它是碎片化的并且作为多个隔离的子网运行，这样全网络范围的攻击便无从实现。
+6. P2P 网络可能受到 [分布式反射拒绝服务攻击](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent) 。客户端有能力重新广播和放大流量，从而导致整个网络范围内的服务中断。 SimpleX 客户端仅中继来自已知连接的流量，因此不能被攻击者用来放大整个网络的流量。
+
+---
+
+### 不同于联邦网络
+
+SimpleX 中继服务器不存储用户配置文件、联系人和传递的消息，不相互连接，并且没有服务器目录。
+
+---
+
+### SimpleX 网络
+
+服务器提供单向队列来连接用户，但是他们看不到网络连接图图谱— 只有用户可以。
+
+## SimpleX 简述
+
+1. 用户会体验到什么
+
+2. 背后的运作原理
+
+3. 服务器能看到什么
+
+1. 用户会体验到什么
+
+您可以创建联系人和群组，并进行双向对话，就像是任何其他即时通讯软件一样。
+
+它是如何利用单向消息队列并不利用用户识别符工作的？
+
+2. 背后的运作原理
+
+对于每个连接，您都会使用两个单独的消息队列，通过不同的服务器发送和接收消息。
+
+服务器只单向传输消息，无法掌握用户的对话或连接的全貌。
+
+3. 服务器能看到什么
+
+服务器对每个队列都有单独的匿名凭证，并且不知道这些凭证属于哪些用户。
+
+用户可以通过使用 Tor 访问服务器以进一步提高元数据隐私，防止通过 IP 地址关联实际身份。
+
+## 与其他协议的比较
+
+|  |  | Signal、其他大平台 | XMPP、Matrix | P2P协议 |
+| --- | --- | --- | --- | --- |
+| 需要全局身份 | 否 - 私密 | 是 [1] | 是 [2] | 是 [3] |
+| 中间人攻击的可能性 | 不可能 - 安全 [4] | 是 [5] | 是 | 是 |
+| 对 DNS 的依赖 | 不依赖 - 有韧性 | 是 | 是 | 否 |
+| 单一或中心化网络 | 不依赖 - 去中心化的 | 是 | 不依赖 - 联邦式网络 [6] | 是 [7] |
+| 中央组件或其他全网攻击 | 不依赖 - 有韧性 | 是 | 是 [2] | 是 [8] |
+
+---
+
+1. 通常基于电话号码，在某些情况下基于用户名
+2. 基于 DNS 的地址
+3. 公钥或其他一些全球唯一的 ID
+4. SimpleX 中继无法破坏 e2e 加密。 验证安全代码以减轻对带外通道的攻击
+5. 如果运营商的服务器受到威胁。 验证 Signal 和其他一些应用程序中的安全代码以缓解该问题
+6. 不保护用户的元数据隐私
+7. P2P 是分布式的，但并非联邦式的 — 它们作为单个网络运行
+8. P2P 网络要么拥有中央权威，要么整个网络可能被攻陷 — [参见此处](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## 不同即时通讯软件端到端加密安全性的比较
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| 消息填充 | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| 否认（可否认性） | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| 前向加密 | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| 事后安全 | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 双因素密钥交换 | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| 后量子混合加密 | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar 将消息大小向上取整至 1024 字节，Signal 消息大小向上取整至 160 字节
+2. 可否认性不包括客户端-服务器连接。
+3. 使用加密签名似乎会损害可否认性（否认能力），但这一点需要澄清。
+4. 多设备部署会降低双棘轮攻击后的安全性 — [参见此处](https://eprint.iacr.org/2021/626.pdf).
+5. 双因素密钥交换可通过安全码验证进行，并非强制要求。
+6. 后量子密钥协商是“稀疏的”——它只保护了部分棘轮步骤。
diff --git a/zh_Hans/messaging/index.html b/zh_Hans/messaging/index.html
index ac045d70b1..ac04c9b093 100644
--- a/zh_Hans/messaging/index.html
+++ b/zh_Hans/messaging/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -717,7 +721,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您有完整的隐私</h3>
                             </div>
 
@@ -768,7 +772,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您可以免受垃圾消息和平台滥用的侵害</h3>
                             </div>
 
@@ -816,7 +820,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您控制您的数据</h3>
                             </div>
 
@@ -867,7 +871,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您拥有 SimpleX 网络</h3>
                             </div>
 
@@ -1209,7 +1213,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">它让消息能在没有用户标识符的情况下传递，并提供比替代方案更好的元数据隐私。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1227,7 +1231,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">为防止这种情况，当您将通讯地址作为链接或二维码共享时，SimpleX 应用程序会在带外传递一次性密钥。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1245,7 +1249,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">每个队列中的网络与密码学库加密盒(NaCL cryptobox)可防止 TLS 受到威胁时消息队列之间的流量关联。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1263,7 +1267,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">如果添加、删除或更改任何消息，收件人都会收到警告。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1279,7 +1283,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">为来信附加服务器加密层，以防止在 TLS 受破坏时接收和发送的服务器流量之间发生关联。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1295,7 +1299,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX 服务器会充当低延迟混合节点，打乱传入和传出消息的顺序。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1315,7 +1319,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">禁用连接恢复以防止会话攻击。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1333,7 +1337,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">要通过 Tor 使用 SimpleX，请安装 <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot</a> 应用并启用 SOCKS5 代理（在 <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">iOS</a>上需要使用 VPN 模式）。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1351,7 +1355,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">与传统的消息代理相比，它减少了攻击媒介和可用的元数据。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1369,7 +1373,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">它使不同大小的消息在服务器和网络监视者看来是一样的。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">点击关闭</p>
                     </div>
                 </div>
                 
@@ -1851,17 +1855,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/old/index.html b/zh_Hans/old/index.html
index 44ce93ab85..233f707333 100644
--- a/zh_Hans/old/index.html
+++ b/zh_Hans/old/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -1098,7 +1102,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您有完整的隐私</h3>
                             </div>
 
@@ -1149,7 +1153,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您可以免受垃圾消息和平台滥用的侵害</h3>
                             </div>
 
@@ -1197,7 +1201,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您控制您的数据</h3>
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@@ -1248,7 +1252,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您拥有 SimpleX 网络</h3>
                             </div>
 
@@ -2159,17 +2163,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hans/why.md b/zh_Hans/why.md
new file mode 100644
index 0000000000..4d20c29af8
--- /dev/null
+++ b/zh_Hans/why.md
@@ -0,0 +1,19 @@
+# 你生来就没有账户。
+
+没有人追踪你的谈话内容。没有人绘制你去过的地方的地图。隐私从来都不是一项功能——而是一种生活方式。
+
+然后我们转向线上，每个平台都要求你提供一些信息——你的姓名、电话号码、好友列表。我们接受了这样一个事实：与人交流的代价就是让别人知道我们在和谁交流。每一代人，每一代科技，都遵循着这样的模式——电话、电子邮件、即时通讯、社交媒体。这似乎是唯一可行的方式。
+
+还有另一种方法。一个没有电话号码、没有用户名、没有账户、没有任何用户身份的网络。一个连接人们并传输加密信息的网络，而无需知道谁连接了。
+
+别人家的门锁再好也比不上这里。房东再好也比不上这里，他既尊重你的隐私，又保留着所有访客的记录。你不是客人，你是家。没有国王能闯入——你是主人。
+
+你的对话内容始终属于你，就像互联网出现之前一样。网络不是一个你访问的地方，而是一个你创建并拥有的地方。无论你将其设为私密还是公开，任何人都无法将其夺走。
+
+人类最古老的自由——与他人交谈而不被监视——建立在不会背叛它的基础设施之上。
+
+因为我们摧毁了知道你是谁的权力，因而*您的*权利永远不会被夺走。
+
+在你的网络中自由畅行。
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/zh_Hans/why/index.html b/zh_Hans/why/index.html
index b454010a59..e0256ffe95 100644
--- a/zh_Hans/why/index.html
+++ b/zh_Hans/why/index.html
@@ -60,6 +60,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hans/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -679,6 +683,10 @@ window.addEventListener('click',(e)=>{
       在你的网络中自由畅行。
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>
 
diff --git a/zh_Hant/contact.md b/zh_Hant/contact.md
new file mode 100644
index 0000000000..c7d6704845
--- /dev/null
+++ b/zh_Hant/contact.md
@@ -0,0 +1,65 @@
+# 您收到了SimpleX聯絡地址
+
+## 使用手提電話或平板電腦中的SimpleX應用程式掃描二維碼。
+
+當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不透過網路傳送；它們包含在連結 URL 的雜湊片段中。
+
+尚未下載SimpleX？
+
+使用以下連結下載應用程式。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+用手機應用程式掃描二維碼
+
+# 您收到了SimpleX聯絡地址
+
+建立連結：
+
+安裝 SimpleX 應用程式
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid)
+
+1
+
+在應用中連結
+
+開啟SimpleX應用程式
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## 使用SimpleX Chat應用程式掃描二維碼
+
+當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 —它們包含在連結 URL 的雜湊片段中。
+
+## 安裝SimpleX至終端
+
+使用此命令：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## 如您已經安裝了用於終端的 SimpleX Chat
+
+如已安裝 用於終端的 SimpleX Chat v1.0.0+, 複製下面的命令並用於聊天：
+
+## 加入 SimpleX
+
+We invite you to join the conversation
+
+[加入Reddit社群](https://www.reddit.com/r/SimpleXChat/) [在GitHub上加入我們](https://github.com/simplex-chat) [於此捐助以幫助我們](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+登記以收取更新
+
+---
+
+下載SimpleX [桌面版應用程式](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid)
diff --git a/zh_Hant/contact/index.html b/zh_Hant/contact/index.html
index b3a74d8936..b696089a2d 100644
--- a/zh_Hant/contact/index.html
+++ b/zh_Hant/contact/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/contact.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,12 +674,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">您收到了SimpleX聯絡地址</h1>
@@ -687,11 +694,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">使用以下連結下載應用程式。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">安裝 SimpleX 應用程式</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">使用SimpleX Chat應用程式掃描二維碼</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 —它們包含在連結 URL 的雜湊片段中。
+                            當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 &mdash;它們包含在連結 URL 的雜湊片段中。
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">安裝SimpleX至終端</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">如您已經安裝了用於終端的 SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">登記以收取更新</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="輸入您的電郵地址">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">下載SimpleX <a href="/downloads">桌面版應用程式</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hant/fdroid.md b/zh_Hant/fdroid.md
new file mode 100644
index 0000000000..062f997a0c
--- /dev/null
+++ b/zh_Hant/fdroid.md
@@ -0,0 +1,25 @@
+# SimpleX Chat - Get the app via F-Droid
+
+## SimpleX Chat via F-Droid
+
+### SimpleX Chat儲存庫
+
+Stable and beta versions built by the developers
+
+掃描二維碼或使用此URL以添加SimpleX儲存庫至您的F-Droid客戶端：
+
+[`https://app.simplex.chat/fdroid/repo`](https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA)
+
+簽名密鑰指紋（SHA-256）:
+
+> 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
+
+### F-Droid.org repo
+
+[SimpleX F-Droid Repository](https://f-droid.org/en/packages/chat.simplex.app/)
+
+由F-Droid.org編譯的穩定版
+
+The releases to this repo are done several days later.
+
+SimpleX Chat 和F-Droid.org 儲存庫使用不同的金鑰為安裝包簽名。若要切換，請[匯出聊天資料庫](https://simplex.chat/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device)並重新安裝應用程式。
diff --git a/zh_Hant/fdroid/index.html b/zh_Hant/fdroid/index.html
index 41e5368c46..b738e37d94 100644
--- a/zh_Hant/fdroid/index.html
+++ b/zh_Hant/fdroid/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/fdroid.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,7 +674,8 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><style>
+        
+<style>
     .hide-on-mobile{
         display: none;
     }
@@ -681,7 +686,7 @@ window.addEventListener('click',(e)=>{
     }
 </style>
 
-</head><body><section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
+<section class="bg-primary-bg-light dark:bg-primary-bg-dark py-[75px] mt-[66px] px-5 lg:h-[calc(100vh-66px)] lg:max-h-[888px] lg:flex lg:items-center">
     <div class="container text-black dark:text-white">
         <h2 class="primary-header text-[35px] leading-[45px] md:leading-[55px] lg:text-[45px] text-center font-bold gradient-text mb-20">SimpleX Chat via F-Droid</h2>
 
@@ -692,16 +697,17 @@ window.addEventListener('click',(e)=>{
                 <div class="flex flex-col-reverse sm:flex-row gap-4">
                     <div>
                         <p class="mb-2 text-lg font-medium mt-6">Stable and beta versions built by the developers</p>
-                        <p><span class="hide-on-mobile">掃描二維碼或</span>使用此URL以添加SimpleX儲存庫至您的F-Droid客戶端：</p>
-                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2" href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
+                        <p><span class='hide-on-mobile'>掃描二維碼或</span>使用此URL以添加SimpleX儲存庫至您的F-Droid客戶端：</p>
+                        <a class="mb-2 break-words text-primary-light dark:text-primary-dark block text-left rtl:text-right text-[14px] xl:text-[16px] leading-[34px] underline-offset-2"
+                            href="https://app.simplex.chat/fdroid/repo?fingerprint=9F358FF284D1F71656A2BFAF0E005DEAE6AA14143720E089F11FF2DDCFEB01BA">
                             <code>https://app.simplex.chat/fdroid/repo</code>
                         </a>
                         <p>
                             簽名密鑰指紋（SHA-256）:
-                            </p><blockquote class="font-bold mt-2">
+                            <blockquote class="font-bold mt-2">
                                 9F 35 8F F2 84 D1 F7 16 56 A2 BF AF 0E 00 5D EA E6 AA 14 14 37 20 E0 89 F1 1F F2 DD CF EB 01 BA
                             </blockquote>
-                        <p></p>
+                        </p>
                     </div>
 
                     <div class="hidden sm:block max-w-[280px] md:max-w-[220px] lg:max-w-[240px]">
@@ -712,25 +718,15 @@ window.addEventListener('click',(e)=>{
 
             <div class="w-full lg:w-2/5">
                 <h3 class="text-grey-black dark:text-white text-[24px] lg:text-[32px] font-bold mb-6">F-Droid.org repo</h3>
-                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                <a class="inline-block" href="https://f-droid.org/en/packages/chat.simplex.app/" target="_blank" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 <p class="mb-2 text-lg font-medium mt-6">由F-Droid.org編譯的穩定版</p>
                 <p class="mb-2">The releases to this repo are done several days later.</p>
-                <p class="mb-2">SimpleX Chat 和F-Droid.org 儲存庫使用不同的金鑰為安裝包簽名。若要切換，請<a href="/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device">匯出聊天資料庫</a>並重新安裝應用程式。</p>
+                <p class="mb-2">SimpleX Chat 和F-Droid.org 儲存庫使用不同的金鑰為安裝包簽名。若要切換，請<a href='/docs/guide/chat-profiles.html#move-your-chat-profiles-to-another-device'>匯出聊天資料庫</a>並重新安裝應用程式。</p>
             </div>
         </div>
 
     </div>
-</section><div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+</section>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hant/file.md b/zh_Hant/file.md
new file mode 100644
index 0000000000..de5d5ad997
--- /dev/null
+++ b/zh_Hant/file.md
@@ -0,0 +1,31 @@
+# SimpleX File Transfer
+
+Drag & drop a file here
+
+or
+
+Choose file
+
+Max 100 MB - [SimpleX Chat app](https://simplex.chat/downloads) supports files up to 1 GB
+
+Send files securely with end-to-end encryption — no accounts, no tracking.
+
+## Get SimpleX Chat — the most secure & private messenger
+
+The file transfer you just used uses the same data routing protocol as SimpleX Chat. The app has end-to-end encrypted messaging, voice and video calls, groups, and sending files. No account. No phone. No email. No user profile IDs.
+
+# XFTP protocol: the most secure file transfer
+
+### No account required
+
+Each file fragment uses a new random key. Data routers have no "users" or "files" - they transfer encrypted file fragments of fixed sizes.
+
+### Triple-encrypted in your browser
+
+File encryption key is present only in the URL hash fragment - your browser never sends it to a server. There are 3 encryption layers: TLS transport, per-recipient encryption (unique ephemeral key per transfer), and file end-to-end encryption.
+
+### Independent data routers
+
+When file is split to fragments, it is sent via network routers operated by independent parties. No operator can see the actual file size or name. Even if a router is compromised, it can only see encrypted fragments of fixed size. File fragments are cached by network routers for approximately 48 hours.
+
+[Read the XFTP protocol specification →](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/xftp.md)
diff --git a/zh_Hant/file/index.html b/zh_Hant/file/index.html
index cc42b55183..87648b42dd 100644
--- a/zh_Hant/file/index.html
+++ b/zh_Hant/file/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/file.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -826,17 +830,7 @@ window.addEventListener('click',(e)=>{
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 </script>
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hant/index.html b/zh_Hant/index.html
index 9e14fa81d6..1e8bca7f04 100644
--- a/zh_Hant/index.html
+++ b/zh_Hant/index.html
@@ -60,6 +60,10 @@
     <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
     <meta name="twitter:card" content="summary"/>
     <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+    
+<link rel="alternate" type="text/markdown" href="/zh_Hant/index.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
     <meta name="theme-color" content="#C1E3FE">
 
     <link rel="preload" href="/img/design_3/cover.webp" as="image" type="image/webp">
@@ -772,11 +776,11 @@ window.addEventListener('click',(e)=>{
                                 <p>Download<br>Desktop App</p>
                             </div>
                         </a>
-                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg"></a>
-                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg"></a>
+                        <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img src="/img/new/apple_store.svg" alt="App Store"></a>
+                        <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank"><img src="/img/new/google_play.svg" alt="Google Play"></a>
                         <a class="f-droid-btn hidden" href="/zh_Hant/fdroid" title="SimpleX app via F-Droid"><img src="/img/new/f_droid.svg"></a>
-                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight"></a>
-                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png"></a>
+                        <a class="testflight-btn hidden" href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="no-border" src="/img/design_3/testflight-dark.png" title="SimpleX iOS beta-release on TestFlight" alt="TestFlight"></a>
+                        <a class="android-btn hidden" href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img src="/img/design_3/android-dark.png" alt="Android APK"></a>
                     </div>
                     <div class="security-btns">
                         <a title="Security Audits" href="https://www.trailofbits.com/about" target="_blank">
@@ -851,7 +855,7 @@ window.addEventListener('click',(e)=>{
 
             <section id="roadmap" class="page-5 page">
                 <div class="area">
-                    <div class="roadmap-labels">
+                    <div class="roadmap-labels" data-markdown-skip>
                         <span class="roadmap-label roadmap-label-now">Now</span>
                         <span class="roadmap-label roadmap-label-1">2026</span>
                         <span class="roadmap-label roadmap-label-2">Jun 2027</span>
diff --git a/zh_Hant/index.md b/zh_Hant/index.md
new file mode 100644
index 0000000000..ae126fd77a
--- /dev/null
+++ b/zh_Hant/index.md
@@ -0,0 +1,73 @@
+[SimpleX domains launch](https://simplex.domains/)
+
+# Be Free
+
+## In Your Network
+
+The first network without user IDs.
+You own your contacts, groups and channels.
+
+Invest in SimpleX Chat. [查看更多.](https://simplex.chat/crowdfunding/)
+
+[Download Desktop App](https://simplex.chat/downloads) [App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX app via F-Droid](https://simplex.chat/zh_Hant/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+[Security Audits](https://www.trailofbits.com/about) [2022](https://simplex.chat/blog/20221108-simplex-chat-v4.2-security-audit-new-website.html) [2024](https://simplex.chat/blog/20241014-simplex-network-v6-1-security-review-better-calls-user-experience.html)
+
+Security
+Audits
+
+[Privacy Guides messenger recommendations](https://www.privacyguides.org/en/real-time-communication/#simplex-chat) [Whonix messenger recommendations](https://www.whonix.org/wiki/Chat#Recommendation) [Heise Online publications](https://www.heise.de/suche/?q=simplex+chat&sort_by=date&rm=search) [Review by Mike Kuketz](https://www.kuketz-blog.de/simplex-eindruecke-vom-messenger-ohne-identifier/) [OptOut podcast interview](https://optoutpod.com/episodes/s3e02-simplexchat/)
+
+## Nobody Can See Who You Talk To
+
+Not even servers – all messages look like random noise.
+
+Tens of millions of messages delivered privately every day.
+
+[Learn more about SimpleX messaging](https://simplex.chat/zh_Hant/messaging)
+
+## You Own The Network
+
+Every contact and group is on your device, not in a server's database.
+
+No single entity controls the network – anyone can run servers.
+
+[Why we are building it](https://simplex.chat/zh_Hant/why)
+
+## 由用戶資助
+
+為保持獨立性，大型頻道和社群將為其伺服器付費。
+
+用戶現在可以投資 SimpleX Chat — 眾籌已上線！
+
+[投資 SimpleX Chat](https://simplex.chat/crowdfunding/)
+
+## SimpleX Roadmap to Free Internet
+
+2026
+
+: Scale to Large Communities
+
+Escaping centralized platforms
+
+Jun 2027
+
+: Sustainable Communities & Servers
+
+Launching Community Credits
+
+Dec 2027
+
+: Make Your Communities Grow
+
+Tools to promote your communities
+
+[SimpleX users group](https://smp4.simplex.im/g#hr4lvFeBmndWMKTwqiodPz3VBo_6UmdGWocXd1SupsM)
+
+## Join SimpleX Communities
+
+More than 2 million people downloaded SimpleX apps.
+
+Find your channels and communities in directory and create your own!
+
+[View SimpleX Directory](https://simplex.chat/directory)
diff --git a/zh_Hant/invitation.md b/zh_Hant/invitation.md
new file mode 100644
index 0000000000..9d86b8ae90
--- /dev/null
+++ b/zh_Hant/invitation.md
@@ -0,0 +1,65 @@
+# 您收到了SimpleX一次性連結
+
+## 使用手提電話或平板電腦中的SimpleX應用程式掃描二維碼。
+
+當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不透過網路傳送；它們包含在連結 URL 的雜湊片段中。
+
+尚未下載SimpleX？
+
+使用以下連結下載應用程式。
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid) [TestFlight](https://testflight.apple.com/join/DWuT2LQu) [Android APK](https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk)
+
+用手機應用程式掃描二維碼
+
+# 您收到了SimpleX一次性連結
+
+建立連結：
+
+安裝 SimpleX 應用程式
+
+[App Store](https://apps.apple.com/us/app/simplex-chat/id1605771084) [Google Play](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid)
+
+1
+
+在應用中連結
+
+開啟SimpleX應用程式
+
+2
+
+Tap the "connect" button in the app
+
+3
+
+## 使用SimpleX Chat應用程式掃描二維碼
+
+當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 —它們包含在連結 URL 的雜湊片段中。
+
+## 安裝SimpleX至終端
+
+使用此命令：
+
+curl -o- https://raw.githubusercontent.com/simplex-chat/simplex-chat/master/install.sh | bash
+
+See SimpleX Chat GitHub repository for the instructions how to download or compile it from the source code.
+
+---
+
+## 如您已經安裝了用於終端的 SimpleX Chat
+
+如已安裝 用於終端的 SimpleX Chat v1.0.0+, 複製下面的命令並用於聊天：
+
+## 加入 SimpleX
+
+We invite you to join the conversation
+
+[加入Reddit社群](https://www.reddit.com/r/SimpleXChat/) [在GitHub上加入我們](https://github.com/simplex-chat) [於此捐助以幫助我們](https://github.com/simplex-chat/simplex-chat#please-support-us-with-your-donations)
+
+登記以收取更新
+
+---
+
+下載SimpleX [桌面版應用程式](https://simplex.chat/downloads)
+
+[Public iOS preview on TestFlight](https://play.google.com/store/apps/details?id=chat.simplex.app) [SimpleX F-Droid Repository](https://simplex.chat/zh_Hant/fdroid)
diff --git a/zh_Hant/invitation/index.html b/zh_Hant/invitation/index.html
index 258645e218..e2f27763d1 100644
--- a/zh_Hant/invitation/index.html
+++ b/zh_Hant/invitation/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/invitation.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,12 +674,15 @@ window.addEventListener('click',(e)=>{
 });
 </script>
 
-        <html><head><script src="/js/flag-anchor.js"></script>
+        
+
+
+    <script src="/js/flag-anchor.js"></script>
     <script src="/js/qrcode.js"></script>
-    <script async="" defer="" src="/js/contact.js"></script>
+    <script async defer src="/js/contact.js"></script>
 
 
-</head><body><section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
+<section class="hidden xl:block h-screen pt-[66px] bg-white dark:bg-gradient-radial-mobile dark:lg:bg-gradient-radial">
     <div class="container m-auto h-full flex items-center justify-between px-5">
         <div class="flex flex-col items-start justify-center w-full h-full">
             <h1 class="text-[38px] leading-[43px] font-bold max-w-[500px] mb-[30px] primary-header-contact">您收到了SimpleX一次性連結</h1>
@@ -687,11 +694,11 @@ window.addEventListener('click',(e)=>{
             <p class="text-grey-black dark:text-white text-base mb-[24px]">使用以下連結下載應用程式。</p>
 
             <div class="flex items-center justify-center gap-4 flex-wrap">
-                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                <a href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+                <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                <a href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+                <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" alt="TestFlight" /></a>
+                <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" alt="Android APK" /></a>
             </div>
         </div>
 
@@ -724,9 +731,9 @@ window.addEventListener('click',(e)=>{
             <div class="flex flex-col justify-center items-center p-4 w-full max-w-[468px] min-h-[131px] rounded-[30px] border-[1px] border-[#A8B0B4] dark:border-white border-opacity-60 mb-6 relative">
                 <p class="text-xl font-medium text-grey-black dark:text-white mb-4">安裝 SimpleX 應用程式</p>
                 <div class="flex flex-wrap items-center justify-center gap-2">
-                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-                    <a class="f-droid-btn hidden" href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
+                    <a class="apple-store-btn hidden" href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" alt="App Store" /></a>
+                    <a class="google-play-btn hidden" href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Google Play"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" alt="Google Play" /></a>
+                    <a class="f-droid-btn hidden" href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
                 </div>
 
                 <div class="absolute bg-[#0197FF] h-[44px] w-[44px] rounded-full flex items-center justify-center top-0 left-0 translate-x-[-30%] translate-y-[-30%]">
@@ -769,14 +776,14 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">使用SimpleX Chat應用程式掃描二維碼</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
 
                     <div class="contact-tab-content flex flex-col gap-10">
                         <p class="text-base mb-5">
-                            當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 —它們包含在連結 URL 的雜湊片段中。
+                            當您檢視此頁面時，此連結中的公鑰和訊息佇列位址不會透過網路傳送 &mdash;它們包含在連結 URL 的雜湊片段中。
                         </p>
                         <canvas class="self-center conn_req_uri_qrcode"></canvas>
                     </div>
@@ -789,7 +796,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">安裝SimpleX至終端</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -806,7 +813,7 @@ window.addEventListener('click',(e)=>{
                                 <span class="text-primary-light dark:text-primary-dark underline underline-offset-4 text-base font-medium">GitHub repository</span>
                                 <svg class="fill-primary-light dark:fill-primary-dark" width="24" height="24" viewBox="0 0 41 41" fill="none" xmlns="http://www.w3.org/2000/svg">
                                     <path d="M20.2907 0.926758C9.24635 0.926758 0.290527 10.1075 0.290527 21.4331C0.290527 30.4933 6.02118 38.18 13.9679 40.8915C14.9674 41.0813 15.3344 40.4467 15.3344 39.905C15.3344 39.4161 15.3158 37.8007 15.3072 36.0872C9.74314 37.3277 8.56906 33.6677 8.56906 33.6677C7.65927 31.2975 6.3484 30.6672 6.3484 30.6672C4.53379 29.3945 6.48519 29.4206 6.48519 29.4206C8.49355 29.5653 9.55105 31.5338 9.55105 31.5338C11.3349 34.6688 14.2298 33.7624 15.3711 33.2385C15.5506 31.9131 16.069 31.0085 16.6409 30.4964C12.1986 29.9779 7.52878 28.2195 7.52878 20.3621C7.52878 18.1232 8.31007 16.294 9.58947 14.8579C9.38181 14.3414 8.69723 12.2557 9.78322 9.43111C9.78322 9.43111 11.4627 8.87998 15.2847 11.5331C16.8801 11.0787 18.591 10.8509 20.2907 10.8431C21.9904 10.8509 23.7027 11.0787 25.301 11.5331C29.1183 8.87998 30.7955 9.43111 30.7955 9.43111C31.8842 12.2557 31.1992 14.3414 30.9916 14.8579C32.274 16.294 33.05 18.1232 33.05 20.3621C33.05 28.2382 28.3712 29.9724 23.9176
-                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z"></path>
+                                        30.4801C24.635 31.1165 25.2742 32.3644 25.2742 34.2776C25.2742 37.0214 25.251 39.2296 25.251 39.905C25.251 40.4507 25.611 41.0902 26.6248 40.8888C34.5672 38.1742 40.2905 30.4903 40.2905 21.4331C40.2905 10.1075 31.336 0.926758 20.2907 0.926758Z" />
                                 </svg>
                             </a>
                             &nbsp;
@@ -820,7 +827,7 @@ window.addEventListener('click',(e)=>{
                     <div class="flex items-center justify-between my-[40px] contact-tab-btn cursor-pointer">
                         <h2 class="text-xl font-bold">如您已經安裝了用於終端的 SimpleX Chat</h2>
                         <svg class="fill-grey-black dark:fill-white" width="10" height="5" viewBox="0 0 10 5" fill="none" xmlns="http://www.w3.org/2000/svg">
-                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"></path>
+                            <path fill-rule="evenodd" clip-rule="evenodd" d="M8.40813 4.79332C8.69689 5.06889 9.16507 5.06889 9.45384 4.79332C9.7426 4.51775 9.7426 4.07097 9.45384 3.7954L5.69327 0.206676C5.65717 0.17223 5.61827 0.142089 5.57727 0.116255C5.29026 -0.064587 4.90023 -0.0344467 4.64756 0.206676L0.886983 3.7954C0.598219 4.07097 0.598219 4.51775 0.886983 4.79332C1.17575 5.06889 1.64393 5.06889 1.93269 4.79332L5.17041 1.70356L8.40813 4.79332Z"/>
                         </svg>
                     </div>
 
@@ -857,10 +864,12 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-base text-center mb-7">登記以收取更新</p>
 
-        <form class="flex items-center w-full max-w-[540px] mb-20" action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe" method="post" target="_blank" novalidate="">
+        <form class="flex items-center w-full max-w-[540px] mb-20"
+            action="https://chat.us2.list-manage.com/subscribe/post?u=ddd892b258ae36e5438e6d4e1&amp;id=ad6037a2fe"
+            method="post" target="_blank" novalidate>
             <input name="EMAIL" type="text" class="h-[44px] ltr:rounded-l-[34px] rtl:rounded-r-[34px] bg-transparent border border-primary-light focus:outline-none text-primary-light dark:text-primary-dark text-base w-full max-w-[400px] px-5 placeholder:text-grey-black placeholder:dark:text-white placeholder:text-base placeholder:font-normal placeholder:tracking-[0.01em]" placeholder="輸入您的電郵地址">
             <span aria-hidden="true" class="hidden">
-                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="">
+                <input type="text" name="b_ddd892b258ae36e5438e6d4e1_ad6037a2fe" tabindex="-1" value="" />
             </span>
             <input type="submit" class="h-[44px] ltr:rounded-r-[34px] rtl:rounded-l-[34px] bg-primary-light text-white text-center px-8">
         </form>
@@ -869,11 +878,11 @@ window.addEventListener('click',(e)=>{
 
         <p class="text-grey-black dark:text-white text-center mb-7">下載SimpleX <a href="/downloads">桌面版應用程式</a></p>
         <div class="flex items-center justify-center gap-4 flex-wrap">
-            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg"></a>
-            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg"></a>
-            <a href="/zh_Hant/fdroid" title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg"></a>
-            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png"></a>
-            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png"></a>
+            <a href="https://apps.apple.com/us/app/simplex-chat/id1605771084" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apple_store.svg" /></a>
+            <a href="https://play.google.com/store/apps/details?id=chat.simplex.app" target="_blank" title="Public iOS preview on TestFlight"><img class="h-[40px] w-auto" src="/img/new/google_play.svg" /></a>
+            <a href="/zh_Hant/fdroid"  title="SimpleX F-Droid Repository"><img class="h-[40px] w-auto" src="/img/new/f_droid.svg" /></a>
+            <a href="https://testflight.apple.com/join/DWuT2LQu" target="_blank"><img class="h-[40px] w-auto" src="/img/new/testflight.png" /></a>
+            <a href="https://github.com/simplex-chat/simplex-chat/releases/latest/download/simplex-aarch64.apk" target="_blank"><img class="h-[40px] w-auto" src="/img/new/apk_icon.png" /></a>
         </div>
     </div>
 </section>
@@ -882,17 +891,7 @@ window.addEventListener('click',(e)=>{
 <script>
     document.querySelectorAll('.d-none-if-js-disabled').forEach(el => el.classList.remove('d-none-if-js-disabled'));
 </script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hant/messaging.md b/zh_Hant/messaging.md
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+# The World's Most Secure Messaging
+
+**Ultimate security**: SimpleX network uses the most secure end-to-end encryption, with continuous post-quantum key exchange to protect all messages and metadata.
+
+**Unique privacy**: SimpleX network has no user profile IDs, not even random numbers or keys. It provides better privacy of your contacts, protecting who you talk with from network servers.
+
+**No spam**: nobody can contact you unless you share 1-time link or long-term address.
+
+**Data ownership**: only your device stores your profiles, contacts and messages. You can securely move your data to another device. Servers store encrypted messages only while your device is offline.
+
+**Secure decentralization**: you control which servers to connect to. For security 4 different servers are used in each chat — they can't observe which IP addresses talk to each other.
+
+#### How to connect to others
+
+- Tap new chat button in the corner, then create 1-time link.
+- Share the link with your contact via any other messenger or email - it is secure.
+- Ask your contact to use the link in the app - click it after the app is installed or paste into the search field in the app.
+
+## SimpleX為何與眾不同
+
+### 您擁有完整的私隱權
+
+SimpleX 保護您的個人資料、聯絡人和元資料的隱私，使其對 SimpleX 網路伺服器和任何觀察者隱藏。
+
+與任何其他現有的訊息網路不同，SimpleX 不指定使用者的標識符—**甚至沒有隨機數**。
+
+### SimpleX保護您免受垃圾訊息、濫用之害
+
+由於您在 SimpleX 網路上沒有任何標識符或固定地址，因此除非您分享一次性或臨時地址 (如 二維碼或連結)，任何人都無法與您聯絡。
+
+### 您掌控您的數據
+
+SimpleX 以 **可攜式加密數據庫格式** 儲存用戶端裝置上的所有使用者資料；這些資料可傳輸至其他設備。
+
+端對端加密的訊息暫時保留在 SimpleX 中繼伺服器上，收到訊息後會被永久刪除。
+
+### 您擁有SimpleX網路
+
+SimpleX 網路是完全去中心化的，獨立於任何加密貨幣或任何其他網路（除Internet）。
+
+您可以**使用您自己的伺服器**運行SimpleX，或使用我們提供的伺服器並仍連線到任何使用者。
+
+# 您的身份、個人資料、聯絡人與詮釋資料完全隱密
+
+與其他通訊網路不同，SimpleX **不為使用者指定標識符**。它不依賴電話號碼、網域地址 (如電子郵件或 XMPP)、用戶名、公鑰或甚至隨機數來識別使用者；SimpleX 伺服器操作員不知道有多少人使用他們的伺服器。
+
+To deliver messages SimpleX uses [pairwise anonymous addresses](https://csrc.nist.gov/glossary/term/Pairwise_Pseudonymous_Identifier) of unidirectional message queues, separate for received and sent messages, usually via different servers.
+
+This design protects the privacy of who you are communicating with, hiding it from SimpleX network servers and from any observers. To hide your IP address from the servers, you can **connect to SimpleX servers via Tor**.
+
+# 防止垃圾郵件和濫用的最佳保護
+
+Because you have no identifier on the SimpleX network, nobody can contact you unless you share a one-time or temporary user address, as a QR code or a link.
+
+Even with the optional user address, while it can be used to send spam contact requests, you can change or completely delete it without losing any of your connections.
+
+# 您的數據的擁有權、控制與安全
+
+SimpleX Chat stores all user data only on client devices using a **portable encrypted database format** that can be exported and transferred to any supported device.
+
+The end-to-end encrypted messages are held temporarily on SimpleX relay servers until received, then they are permanently deleted.
+
+Unlike federated networks servers (email, XMPP or Matrix), SimpleX servers don't store user accounts, they only relay messages, protecting the privacy of both parties.
+
+傳送與接收的伺服器流量之間沒有共同的標識符或密文—如果有人觀察，即使 TLS 遭到破壞，也無法輕易確定誰與誰通訊。
+
+# 完全去中心化—用戶擁有 SimpleX 網路
+
+您可以**使用您自己的伺服器**運行SimpleX，並仍與使用應用程式中預設伺服器的人進行通訊。
+
+SimpleX網路使用[開源協議](https://github.com/simplex-chat/simplexmq/blob/stable/protocol/overview-tjr.md)並提供[開發包以編寫聊天機器人](https://github.com/simplex-chat/simplex-chat/tree/stable/packages/simplex-chat-client/typescript)，允許使用者透過SimpleX Chat應用程式與服務互動—我們非常期待看到您的SimpleX服務之作！
+
+如您正考慮針對 SimpleX 網路進行開發，例如針對 SimpleX 使用者的聊天機器人，或將 SimpleX 聊天函式庫整合至您的手機應用程式，請[與我們聯絡](https://simplex.chat/contact#/?v=1&smp=smp%3A%2F%2FPQUV2eL0t7OStZOoAsPEV2QYWt4-xilbakvGUGOItUo%3D%40smp6.simplex.im%2FK1rslx-m5bpXVIdMZg9NLUZ_8JBm8xTt%23MCowBQYDK2VuAyEALDeVe-sG8mRY22LsXlPgiwTNs9dbiLrNuA7f3ZMAJ2w%3D)以獲取支持與建議。
+
+## 特徵
+
+支持Markdown與編輯的、端到端加密的訊息
+
+端到端加密的圖像、視訊、檔案
+
+端到端加密的、去中心化的群組—存在只有用戶自己知道
+
+端到端加密的語音訊息
+
+自刪除訊息
+
+端到端加密的語音、視訊通話
+
+可攜、加密存儲—將設定檔移至另一設備
+
+隱身模式—SimpleX獨有
+
+## What makes SimpleX private
+
+### 臨時匿名標識符對
+
+對用戶與群組成員，SimpleX使用臨時、匿名的地址對與憑證對。
+
+SimpleX使不用用戶設定檔傳輸訊息成為可能，與其他軟體相比提供更強的詮釋資料私隱性。
+
+### 頻帶外密鑰交換
+
+許多通訊網路容易受到伺服器或網路供應商的中間人攻擊。
+
+To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.
+
+### 雙層端到端加密
+
+雙棘輪協定—帶有前向保密、入侵恢復特質的不留記錄即時通訊協定。
+
+如TLS安全受威脅，每個隊列中的NaCL cryptobox可防止關聯訊息隊列間的通訊。
+
+### 訊息完整性驗證
+
+To guarantee integrity the messages are sequentially numbered and include the hash of the previous message.
+
+If any message is added, removed or changed the recipient will be alerted.
+
+### 伺服器附加加密層
+
+傳送至收件者的伺服器加密附加層，以防止 TLS 遭到攻擊時，接收和傳送的伺服器流量之間的關聯。
+
+### 訊息混雜以降低關聯性
+
+SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.
+
+### 經安全鑑權的TLS 傳送
+
+Only TLS 1.2/1.3 with strong algorithms is used for client-server connections.
+
+Server fingerprint and channel binding prevent MITM and replay attacks.
+
+連線恢復被停用，以防止會話攻擊。
+
+### 選擇性 經由 Tor 訪問
+
+為保護您的 IP 位址，您可透過 Tor 或其他傳輸覆蓋網路訪問伺服器。
+
+To use SimpleX via Tor please install [Orbot app](https://guardianproject.info/apps/org.torproject.android/) and enable SOCKS5 proxy (or VPN [on iOS](https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone)).
+
+### 單向訊息隊列
+
+Each message queue passes messages in one direction, with the different send and receive addresses.
+
+與傳統的訊息代理相比，它可減小攻擊媒介及可見的詮釋資料量。
+
+### 多層內容填充
+
+SimpleX 為每個加密層使用內容填充，以挫敗通過監控訊息長度的攻擊。
+
+它讓不同長度的訊息在伺服器和網路觀察者看來相同。
+
+## SimpleX Network
+
+SinpleX Chat 結合點對點和互聯網路的優點，提供最佳的隱私性。
+
+### Unlike P2P networks
+
+所有訊息都經由伺服器傳送，既能提供更好的元資料隱私和可靠的異步訊息傳送，又能避免許多 .
+
+# 與點對點訊息傳輸協定的比較
+
+[點對點](https://en.wikipedia.org/wiki/Peer-to-peer)通訊協定和應用程式有多種問題，使得它們不如 SimpleX 可靠、分析起來更複雜，而且易受幾種類型的攻擊。
+
+1. 點對點網路依賴 [DHT](https://en.wikipedia.org/wiki/Distributed_hash_table) 的某些變體來路由訊息。DHT 設計必須平衡傳送保證和延遲。與點對點相比，SimpleX 具有更好的傳送保證和更低的延遲，因為訊息可以使用收件者選擇的伺服器，經由多個伺服器並行冗餘地傳送。在點對點網路中，訊息依次經由*O(log N)*個由演算法選擇的節點。
+2. SimpleX 的設計與大多數點對點網路不同，沒有任何類型的全局使用者標識符，即使是臨時標識符。SimpleX 只使用臨時的標識符對，提供更好的匿名性和元資料保護。
+3. P2P does not solve [MITM attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) problem, and most existing implementations do not use out-of-band messages for the initial key exchange. SimpleX uses out-of-band messages or, in some cases, pre-existing secure and trusted connections for the initial key exchange.
+4. P2P implementations can be blocked by some Internet providers (like [BitTorrent](https://en.wikipedia.org/wiki/BitTorrent)). SimpleX is transport agnostic — it can work over standard web protocols, e.g. WebSockets.
+5. All known P2P networks may be vulnerable to [Sybil attack](https://en.wikipedia.org/wiki/Sybil_attack), because each node is discoverable, and the network operates as a whole. Known measures to mitigate it require either a centralized component or expensive [proof of work](https://en.wikipedia.org/wiki/Proof_of_work). SimpleX network has no server discoverability, it is fragmented and operates as multiple isolated sub-networks, making network-wide attacks impossible.
+6. P2P networks may be vulnerable to [DRDoS attack](https://www.usenix.org/conference/woot15/workshop-program/presentation/p2p-file-sharing-hell-exploiting-bittorrent), when the clients can rebroadcast and amplify traffic, resulting in network-wide denial of service. SimpleX clients only relay traffic from known connections and cannot be used by an attacker to amplify the traffic in the whole network.
+
+---
+
+### 與互聯網路不同
+
+SimpleX 中繼伺服器不儲存使用者個人資料、聯絡人和傳送的訊息，也不連線彼此，也沒有伺服器目錄。
+
+---
+
+### SimpleX網路
+
+伺服器提供單向佇列以連接使用者，但伺服器無法看到網路連線圖 —只有使用者能看到。
+
+## SimpleX 解釋
+
+1. 用戶體驗
+
+2. 它是如何工作的
+
+3. 伺服器可以看到什麼
+
+1. 用戶體驗
+
+你可以建立聯絡人和群組，並進行雙向對話，就像在任何其他即時通訊軟件中一樣。
+
+它如何在沒有使用者個人檔案識別符的情況下使用單向佇列？
+
+2. 它是如何工作的
+
+對於每個連接，您可以使用兩個單獨的消息佇列通過不同的伺服器發送和接收消息。
+
+伺服器僅單向傳遞消息，無法全面瞭解使用者的對話記錄或連接。
+
+3. 伺服器可以看到什麼
+
+伺服器對每個佇列都有單獨的匿名憑證，並且不知道它們屬於哪些使用者。
+
+用戶可以通過使用 Tor 訪問伺服器來進一步提高元數據隱私，防止按 IP 位址進行序列化。
+
+## 與其他協議之比較
+
+|  |  | Signal，大平台 | XMPP、Matrix | 點對點協議 |
+| --- | --- | --- | --- | --- |
+| 需要全局身份 | No - private | Yes [1] | Yes [2] | Yes [3] |
+| 中間人攻擊之可能 | No - secure [4] | Yes [5] | Yes | Yes |
+| 對DNS的依賴 | No - resilient | Yes | Yes | No |
+| 單一或集中式網路 | No - decentralized | Yes | No - federated [6] | Yes [7] |
+| Central component or other network-wide attack | No - resilient | Yes | Yes [2] | Yes [8] |
+
+---
+
+1. 通常基於電話號碼，有時用戶名
+2. 基於DNS的位址
+3. 公鑰或其他某種全局獨一的標識符
+4. SimpleX中繼不可能威脅端到端加密。由其他方式驗證安全碼以杜絕攻擊之可能
+5. 如果運營商的伺服器受到攻擊，用其他應用程式（如 Signal）驗證 SimpleX 安全碼，以減輕風險
+6. 不保護使用者的元數據隱私
+7. While P2P are distributed, they are not federated — they operate as a single network
+8. 點對點網路必須有中央權威，否則整個網路都可能受到攻擊 — [見此](https://github.com/simplex-chat/simplex-chat/blob/stable/docs/SIMPLEX.md#comparison-with-p2p-messaging-protocols)
+
+## Comparison of end-to-end encryption security in different messengers
+
+|  | Session | Briar | Element | Cwtch | Signal | SimpleX |
+| --- | --- | --- | --- | --- | --- | --- |
+| Message padding | ✗ | ✔︎[1] | ✗ | ✔︎ | ✔︎[1] | ✔︎ |
+| Repudiation (deniability) | ✗ | ✗ | ✗ | ✔︎[2] | ✔︎[3] | ✔︎ |
+| Forward secrecy | ✗ | ✔︎ | ✔︎ | ✔︎ | ✔︎ | ✔︎ |
+| Post-compromise security | ✗ | ✗ | ✗ | ✔︎ | ✗[4] | ✔︎ |
+| 2-factor key exchange | ✔︎ | ✔︎[5] | ✔︎[5] | ✔︎ | ✔︎[5] | ✔︎ |
+| Post-quantum hybrid crypto | ✗ | ✗ | ✗ | ✗ | ✔︎[6] | ✔︎ |
+
+---
+
+1. Briar pads messages to the size rounded up to 1024 bytes, Signal - to 160 bytes
+2. Repudiation does not include client-server connection.
+3. It appears that the usage of cryptographic signatures compromises repudiation (deniability), but it needs to be clarified.
+4. Multi-device implementation compromises post-compromise security of Double Ratchet — [見此](https://eprint.iacr.org/2021/626.pdf).
+5. 2-factor key exchange is optional via security code verification.
+6. Post-quantum key agreement is "sparse" — it protects only some of the ratchet steps.
diff --git a/zh_Hant/messaging/index.html b/zh_Hant/messaging/index.html
index f8684e9b2f..7beae4b2d5 100644
--- a/zh_Hant/messaging/index.html
+++ b/zh_Hant/messaging/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/messaging.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -708,7 +712,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您擁有完整的私隱權</h3>
                             </div>
 
@@ -759,7 +763,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX保護您免受垃圾訊息、濫用之害</h3>
                             </div>
 
@@ -807,7 +811,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您掌控您的數據</h3>
                             </div>
 
@@ -858,7 +862,7 @@ window.addEventListener('click',(e)=>{
 
                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
                             <div class="content-head">
-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您擁有SimpleX網路</h3>
                             </div>
 
@@ -1200,7 +1204,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX使不用用戶設定檔傳輸訊息成為可能，與其他軟體相比提供更強的詮釋資料私隱性。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1218,7 +1222,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To prevent it SimpleX apps pass one-time keys out-of-band, when you share an address as a link or a QR code.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1236,7 +1240,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">如TLS安全受威脅，每個隊列中的NaCL cryptobox可防止關聯訊息隊列間的通訊。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1254,7 +1258,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">If any message is added, removed or changed the recipient will be alerted.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1270,7 +1274,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">傳送至收件者的伺服器加密附加層，以防止 TLS 遭到攻擊時，接收和傳送的伺服器流量之間的關聯。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1286,7 +1290,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">SimpleX servers act as low latency mix nodes — the incoming and outgoing messages have different order.</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1306,7 +1310,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">連線恢復被停用，以防止會話攻擊。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1324,7 +1328,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">To use SimpleX via Tor please install <a href="https://guardianproject.info/apps/org.torproject.android/" target="_blank">Orbot app</a> and enable SOCKS5 proxy (or VPN <a href="https://apps.apple.com/us/app/orbot/id1609461599?platform=iphone" target="_blank">on iOS</a>).</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1342,7 +1346,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">與傳統的訊息代理相比，它可減小攻擊媒介及可見的詮釋資料量。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1360,7 +1364,7 @@ window.addEventListener('click',(e)=>{
                             <p class="text-grey-black dark:text-white text-[14px] text-center">它讓不同長度的訊息在伺服器和網路觀察者看來相同。</p>
                             
                         </div>
-                        <p class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
+                        <p data-markdown-skip="" class="text-grey-black dark:text-white text-[12px] text-center">輕觸以關閉</p>
                     </div>
                 </div>
                 
@@ -1842,17 +1846,7 @@ window.addEventListener("load", function () {
 </section>
 
 
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-end-to-end-encryption" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">End-to-end encryption</h4><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="end-to-end-encryption">Read more</button></div></div><div id="tooltip-forward-secrecy" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Forward secrecy</h4><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="forward-secrecy">Read more</button></div></div><div id="tooltip-key-exchange" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Key exchange</h4><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="key-exchange">Read more</button></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-message-padding" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Message padding</h4><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="message-padding">Read more</button></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-post-compromise-security" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-compromise security</h4><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div></div><div id="tooltip-post-quantum-hybrid-crypto" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Post-quantum hybrid crypto</h4><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="post-quantum-hybrid-crypto">Read more</button></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-repudiation" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">Repudiation</h4><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="repudiation">Read more</button></div></div></body></html>
 
         
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         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
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         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#1</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您擁有完整的私隱權</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#2</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">SimpleX保護您免受垃圾訊息、濫用之害</h3>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#3</h1>
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                         <div class="card-content absolute md:static px-4 md:px-0 bottom-[80px] right-1 left-1 h-[180px] md:h-fit pt-5 lg:pt-0 bg-primary-bg-light dark:bg-primary-bg-dark">
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-                                <h1 class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
+                                <h1 data-markdown-skip="" class="text-[35px] lg:text-[65px] font-bold tracking-[0.06em] text-active-blue text-center md:text-left md:rtl:text-right">#4</h1>
                                 <h3 class="w-full max-w-[617px] text-[25px] leading-[33px] lg:text-[35px] lg:leading-[45px] text-center md:text-left md:rtl:text-right font-bold text-grey-black dark:text-white">您擁有SimpleX網路</h3>
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@@ -2150,17 +2154,7 @@ window.addEventListener("load", function () {
 
 
 <script src="/js/animation.js"></script>
-<div id="address-portability" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Address portability</h1><div class="overlay-content"><p>Similarly to <a href="https://en.wikipedia.org/wiki/Local_number_portability">phone number portability</a> (the ability of the customer to transfer the service to another provider without changing the number), the address portability means the ability of a communication service customer to change the service provider without changing the service address. Many <a href="#federated-network">federated networks</a> support SRV records to provide address portability, but allowing service users to set up their own domains for the addresses is not as commonly supported by the available server and client software as for email.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="federated-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Federated network</h1><div class="overlay-content"><p>Federated network is provided by several entities that agree upon the standards and operate the network collectively. This allows the users to choose their provider, that will hold their account, their messaging history and contacts, and communicate with other providers' servers on behalf of the user. The examples are email, XMPP, Matrix and Mastodon.</p><p>The advantage of that design is that there is no single organization that all users depend on, and the standards are more difficult to change, unless it benefits all users. There are several disadvantages: 1) the innovation is slower, 2) each user account still depends on a single organization, and in most cases can't move to another provider without changing their network address – there is no <a href="#address-portability">address portability</a>, 3) the security and privacy are inevitably worse than with the centralized networks.</p><p><a href="https://en.wikipedia.org/wiki/Federation_(information_technology)">Federation on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="anonymous-credentials" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Anonymous credentials</h1><div class="overlay-content"><p>The credential that allows proving something, e.g. the right to access some resource, without identifying the user. This credential can either be generated by a trusted party or by the user themselves and provided together with the request to create the resource. The first approach creates some centralized dependency in most cases. The second approach does not require any trust - this is used in SimpleX network to authorize access to the messaging queues.</p><p><a href="https://en.wikipedia.org/wiki/Digital_credential">Digital credential on Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="blockchain" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Blockchain</h1><div class="overlay-content"><p>In a wide sense, blockchain means a sequence of blocks of data, where each block contains a cryptographic hash of the previous block, thus providing integrity to the whole chain. Blockchains are used in many communication and information storage systems to provide integrity and immutability of the data. For example, BluRay disks use blockchain. SimpleX messaging queues also use blockchain - each message includes the hash of the previous message, to ensure the integrity – if any message is modified it will be detected by the recipient when the next message is received. Blockchains are a subset of <a href="#merkle-directed-acyclic-graph">Merkle directed acyclic graphs</a>.</p><p>In a more narrow sense, particularly in media, blockchain is used to refer specifically to distributed ledger, where each record also includes the hash of the previous record, but the blocks have to be agreed by the participating peers using some <a href="https://en.wikipedia.org/wiki/Consensus_(computer_science)">consensus protocol</a>.</p><p><a href="https://en.wikipedia.org/wiki/Blockchain">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="merkle-directed-acyclic-graph" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Merkle directed acyclic graph</h1><div class="overlay-content"><p>Also known as Merkle DAG, a data structure based on a general graph structure where node contains the cryptographic hashes of the previous nodes that point to it. Merkle trees are a subset of Merkle DAGs - in this case each leaf contains a cryptographic hash of the parent.</p><p>This structure by design allows to verify the integrity of the whole structure by computing its hashes and comparing with the hashes included in the nodes, in the same way as with <a href="#blockchain">blockchain</a>.</p><p>The motivation to use DAG in distributed environments instead of a simpler linear blockchain is to allow concurrent additions, when there is no requirement for a single order of added items. Merkle DAG is used, for example, in <a href="https://en.wikipedia.org/wiki/InterPlanetary_File_System">IPFS</a> and will be used in decentralized SimpleX groups.</p><p><a href="https://en.wikipedia.org/wiki/Merkle_tree">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="break-in-recovery" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Break-in recovery</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="double-ratchet-algorithm" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Double ratchet algorithm</h1><div class="overlay-content"><p>It is used by two parties to exchange <a href="#end-to-end-encryption">end-to-end encrypted</a> messages. The parties will use some <a href="#key-agreement-protocol">key agreement protocol</a> to agree on the initial shared secret key.</p><p>Double Ratchet algorithm provides <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>. It is <a href="https://signal.org/docs/specifications/doubleratchet">designed by Signal</a>, and used in SimpleX Chat and many other secure messengers. Most experts consider it the state-of-the-art encryption protocol in message encryption.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="centralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Centralized network</h1><div class="overlay-content"><p>Centralized networks are provided or controlled by a single entity. The examples are Threema, Signal, WhatsApp and Telegram. The advantage of that design is that the provider can innovate faster, and has a centralized approach to security. But the disadvantage is that the provider can change or discontinue the service, and leak, sell or disclose in some other way all users' data, including who they are connected with.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="content-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Content padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="decentralized-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Decentralized network</h1><div class="overlay-content"><p>Decentralized network is often used to mean "the network based on decentralized blockchain". In its original meaning, decentralized network means that there is no central authority or any other point of centralization in the network, other than network protocols specification. The advantage of decentralized networks is that they are resilient to censorship and to the provider going out of business. The disadvantage is that they are often slower to innovate, and the security may be worse than with the centralized network.</p><p>The examples of decentralized networks are email, web, DNS, XMPP, Matrix, BitTorrent, etc. All these examples have a shared global application-level address space. Cryptocurrency blockchains not only have a shared address space, but also a shared state, so they are more centralized than email. Tor network also has a shared global address space, but also a central authority. SimpleX network does not have a shared application-level address space (it relies on the shared transport-level addresses - SMP relay hostnames or IP addresses), and it does not have any central authority or any shared state.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="defense-in-depth" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Defense in depth</h1><div class="overlay-content"><p>Originally, it is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space.</p><p>In information security, defense in depth represents the use of multiple computer security techniques to help mitigate the risk of one component of the defense being compromised or circumvented. An example could be anti-virus software installed on individual workstations when there is already virus protection on the firewalls and servers within the same environment.</p><p>SimpleX network applies defense in depth approach to security by having multiple layers for the communication security and privacy:</p><ul>
-<li>double ratchet algorithm for <a href="#end-to-end-encryption">end-to-end encryption</a> with <a href="#forward-secrecy">perfect forward secrecy</a> and <a href="#post-compromise-security">post-compromise security</a>,</li>
-<li>additional layer of end-to-end encryption for each messaging queue and another encryption layer of encryption from the server to the recipient inside TLS to prevent correlation by ciphertext,</li>
-<li>TLS with only strong ciphers allowed,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-server connection via server offline certificate verification,</li>
-<li>mitigation of replay attacks via signing over transport channel binding,</li>
-<li>multiple layers of <a href="#message-padding">message padding</a> to reduce efficiency of traffic analysis,</li>
-<li>mitigation of <a href="#man-in-the-middle-attack">man-in-the-middle attack</a> on client-client out-of-band channel when sending the invitation,</li>
-<li>rotation of delivery queues to reduce efficiency of traffic analysis,</li>
-<li>etc.</li>
-</ul><p><a href="https://en.wikipedia.org/wiki/Defence_in_depth">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-compromise-security" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-compromise security</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="message-padding" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Message padding</h1><div class="overlay-content"><p>Also known as content padding, it is the process of adding data to the beginning or the end of a message prior to encryption. Padding conceals the actual message size from any eavesdroppers. SimpleX has several encryption layers, and prior to each encryption the content is padded to a fixed size.</p><p><a href="https://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-exchange" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key exchange</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="non-repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Non-repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the recipient of the message to prove to any third party that the sender identified by some cryptographic key sent the message. It is the opposite to <a href="#repudiation">repudiation</a>. While in some context non-repudiation may be desirable (e.g., for contractually binding messages), in the context of private communications it may be undesirable.</p><p><a href="https://en.wikipedia.org/wiki/Non-repudiation">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="repudiation" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Repudiation</h1><div class="overlay-content"><p>The property of the cryptographic or communication system that allows the sender of the message to plausibly deny having sent the message, because while the recipient can verify that the message was sent by the sender, they cannot prove it to any third party - the recipient has a technical ability to forge the same encrypted message. This is an important quality of private communications, as it allows to have the conversation that can later be denied, similarly to having a private face-to-face conversation.</p><p>See also <a href="#non-repudiation">non-repudiation</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="onion-routing" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Onion routing</h1><div class="overlay-content"><p>A technique for anonymous communication over a computer network that uses multiple layers of message encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes.</p><p>The most widely used onion network is <a href="https://en.wikipedia.org/wiki/Tor_(network)">Tor</a>.</p><p>Some elements of SimpleX network use similar ideas in their design - different addresses for the same resource used by different parties, and additional encryption layers. Currently though, SimpleX messaging protocol does not protect sender network address, as the relay server is chosen by the recipient. The delivery relays chosen by sender that are planned for the future would make SimpleX design closer to onion routing.</p><p><a href="https://en.wikipedia.org/wiki/Onion_routing">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="overlay-network" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Overlay network</h1><div class="overlay-content"><p>Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. Tor, for example, is an overlay network on top of IP network, which in its turn is also an overlay network over some underlying physical network.</p><p>SimpleX Clients also form a network using SMP relays and IP or some other overlay network (e.g., Tor), to communicate with each other. SMP relays, on another hand, do not form a network.</p><p><a href="https://en.wikipedia.org/wiki/Overlay_network">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="pairwise-pseudonymous-identifier" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Pairwise pseudonymous identifier</h1><div class="overlay-content"><p>Generalizing <a href="https://csrc.nist.gov/glossary/term/pairwise_pseudonymous_identifier">the definition</a> from NIST Digital Identity Guidelines, it is an opaque unguessable identifier generated by a service used to access a resource by only one party.</p><p>In the context of SimpleX network, these are the identifiers generated by SMP relays to access anonymous messaging queues, with a separate identifier (and access credential) for each accessing party: recipient, sender and an optional notifications subscriber. The same approach is used by XFTP relays to access file chunks, with separate identifiers (and access credentials) for sender and each recipient.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Peer-to-peer</h1><div class="overlay-content"><p>Peer-to-peer (P2P) is the network architecture when participants have equal rights and communicate directly via a general purpose transport or overlay network. Unlike client-server architecture, all peers in a P2P network both provide and consume the resources. In the context of messaging, P2P architecture usually means that the messages are sent between peers, without user accounts or messages being stored on any servers. Examples are Tox, Briar, Cwtch and many others.</p><p>The advantage is that the participants do not depend on any servers. There are <a href="/docs/simplex.html#comparison-with-p2p-messaging-protocols">multiple downsides</a> to that architecture, such as no asynchronous message delivery, the need for network-wide peer addresses, possibility of network-wide attacks, that are usually mitigated only by using a centralized authority. These disadvantages are avoided with <a href="#proxied-peer-to-peer">proxied P2P</a> architecture.</p><p><a href="https://en.wikipedia.org/wiki/Peer-to-peer">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="proxied-peer-to-peer" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Proxied peer-to-peer</h1><div class="overlay-content"><p>Network topology of the communication system when peers communicate via proxies that do not form the network themselves. Such design is used in Pond, that has a fixed home server for each user, and in SimpleX, that uses multiple relays providing temporary connections.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="perfect-forward-secrecy" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Perfect forward secrecy</h1><div class="overlay-content"><p>Also known as perfect forward secrecy, it is a feature of a <a href="#key-agreement-protocol">key agreement protocol</a> that ensures that session keys will not be compromised even if long-term secrets used in the session key exchange are compromised. Forward secrecy protects past sessions against future compromises of session or long-term keys.</p><p><a href="https://en.wikipedia.org/wiki/Forward_secrecy">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-cryptography" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum cryptography</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="post-quantum-hybrid-crypto" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Post-quantum hybrid crypto</h1><div class="overlay-content"><p>Any of the proposed cryptographic systems or algorithms that are thought to be secure against an attack by a quantum computer. It appears that as of 2025 there is no system or algorithm that is <em>proven</em> to be secure against such attacks, or even to be secure against attacks by massively parallel conventional computers, so a general recommendation is to use post-quantum hybrid cryptography - combining post-quantum and traditional algorithms.</p><p><a href="https://en.wikipedia.org/wiki/Post-quantum_cryptography">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="recovery-from-compromise" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Recovery from compromise</h1><div class="overlay-content"><p>The quality of the end-to-end encryption scheme allowing to recover security against a passive attacker who observes encrypted messages after compromising one (or both) of the parties. Also known as recovery from compromise or break-in recovery. <a href="#double-ratchet-algorithm">Double-ratchet algorithm</a> has this quality.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="user-identity" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">User identity</h1><div class="overlay-content"><p>In a communication system it refers to anything that uniquely identifies the users to the network. Depending on the communication network, it can be a phone number, email address, username, public key or a random opaque identifier. Most messaging networks rely on some form of user identity. SimpleX appears to be the only messaging network that does not rely on any kind of user identity - see <a href="https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols">this comparison</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
+<div id="end-to-end-encryption" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">End-to-end encryption</h1><div class="overlay-content"><p>A communication system where only the communicating parties can read the messages. It is designed to protect message content from any potential eavesdroppers – telecom and Internet providers, malicious actors, and also the provider of the communication service.</p><p>End-to-end encryption requires agreeing cryptographic keys between the sender and the recipient in a way that no eavesdroppers can access the agreed keys. See <a href="#key-agreement-protocol">key agreement protocol</a>. This key exchange can be compromised via <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>, particularly if key exchange happens via the same communication provider and no out-of-band channel is used to verify key exchange.</p><p><a href="https://en.wikipedia.org/wiki/End-to-end_encryption">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="man-in-the-middle-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Man-in-the-middle attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="key-agreement-protocol" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">Key agreement protocol</h1><div class="overlay-content"><p>Also known as key exchange, it is a process of agreeing cryptographic keys between the sender and the recipient(s) of the message. It is required for <a href="#end-to-end-encryption">end-to-end encryption</a> to work. Unless it is possible to secure the key exchange via <a href="#2-factor-key-exchange">some second factor</a>, e.g. security code verification, it can be vulnerable to <a href="#man-in-the-middle-attack">man-in-the-middle attack</a>.</p><p><a href="https://en.wikipedia.org/wiki/Key-agreement_protocol">Wikipedia</a></p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div><div id="tooltip-mitm-attack" class="glossary-tooltip"><div class="tooltip-content"><h4 class="tooltip-title">MITM attack</h4><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><button class="read-more-btn open-overlay-btn" data-show-overlay="mitm-attack">Read more</button></div></div><div id="mitm-attack" class="overlay glossary-overlay hidden"><div class="overlay-card"><h1 class="overlay-title">MITM attack</h1><div class="overlay-content"><p>The attack when the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other.</p><p>This attack can be used to compromise <a href="#end-to-end-encryption">end-to-end encryption</a> by intercepting public keys during <a href="#key-agreement-protocol">key exchange</a>, substituting them with the attacker's keys, and then intercepting and re-encrypting all messages, without altering their content. With this attack, while the attacker does not change message content, but she can read the messages, while the communicating parties believe the messages are end-to-end encrypted.</p><p>Such attack is possible with any system that uses the same channel for key exchange as used to send messages - it includes almost all communication systems except SimpleX, where the initial public key is always passed out-of-band. Even with SimpleX, the attacker may intercept and substitute the key sent via another channel, gaining access to communication. This risk is substantially lower, as attacker does not know in advance which channel will be used to pass the key.</p><p>To mitigate such attack the communicating parties must verify the integrity of key exchange - SimpleX and many other messaging apps, e.g. Signal and WhatsApp, have the feature that allows it.</p><p><a href="https://en.wikipedia.org/wiki/Man-in-the-middle_attack">Wikipedia</a>.</p></div><svg class="close-overlay-btn" id="cross" width="16" height="16" viewBox="0 0 13 13" xmlns="http://www.w3.org/2000/svg"><path d="M12.7973 11.5525L7.59762 6.49833L12.7947 1.44675C13.055 1.19371 13.0658 0.771991 12.8188 0.505331C12.5718 0.238674 12.1602 0.227644 11.8999 0.480681L6.65343 5.58028L1.09979 0.182228C0.805 0.002228 0.430001 0.002228 0.135211 0.182228C-0.159579 0.362228 -0.159579 0.697228 0.135211 0.877228L5.68885 6.27528L0.4918 11.3295C0.231501 11.5825 0.220703 12.0042 0.467664 12.2709C0.714625 12.5376 1.12625 12.5486 1.38655 12.2956L6.63302 7.196L12.1867 12.5941C12.4815 12.7741 12.8565 12.7741 13.1513 12.5941C13.4461 12.4141 13.4461 12.0791 13.1513 11.8991L12.7973 11.5525Z"></path></svg></div></div></body></html>
 
         
 <section class="bg-[#D3E9FF] dark:bg-[#080D25] py-[50px] footer page">
diff --git a/zh_Hant/why.md b/zh_Hant/why.md
new file mode 100644
index 0000000000..8dbe7180ca
--- /dev/null
+++ b/zh_Hant/why.md
@@ -0,0 +1,19 @@
+# You were born without an account.
+
+Nobody tracked your conversations. No one drew a map of where you'd been. Privacy was never a feature — it was the way of life.
+
+Then we moved online, and every platform asked for a piece of you — your name, your number, your friends. We accepted that the price of talking to others is letting someone know who we talk to. Every generation, people and tech, had it this way — telephone, email, messengers, social media. It seemed the only way possible.
+
+There is another way. A network with no phone numbers. No usernames. No accounts. No user identities of any kind. A network that connects people and carries encrypted messages without knowing who is connected.
+
+Not a better lock on someone else's door. Not a nicer landlord that respects your privacy, but still keeps the record of all visitors. You are not a guest. You are home. No king can enter it — you are sovereign.
+
+Your conversations belong to you, as it had always been before the Internet. The network is not a place you visit. It is a place you create and own. And nobody can take it from you, whether you make it private or public.
+
+The oldest human freedom — to speak to another person without being watched — built on infrastructure that cannot betray it.
+
+Because we destroyed the power to know who you are. So that *your* power can never be taken.
+
+Be free in your network.
+
+[Watch the film](https://www.youtube.com/watch?v=k-GhLNZm8G0)
diff --git a/zh_Hant/why/index.html b/zh_Hant/why/index.html
index 5e911a701f..060746972a 100644
--- a/zh_Hant/why/index.html
+++ b/zh_Hant/why/index.html
@@ -58,6 +58,10 @@
         <meta property="og:image" content="https://simplex.chat/img/share_simplex.jpg"/>
         <meta name="twitter:card" content="summary"/>
         <link rel="icon" type="image/png" sizes="96x96" href="/img/favicon.ico"/>
+        
+<link rel="alternate" type="text/markdown" href="/zh_Hant/why.md"/>
+<link rel="describedby" href="/llms.txt"/>
+
         <meta name="theme-color" content="#F3FAFF">
 
         <link rel="stylesheet" href="/css/swiper-bundle.min.css">
@@ -670,6 +674,10 @@ window.addEventListener('click',(e)=>{
       Be free in your network.
     </p>
 
+    <p class="mt-10 md:mt-14 text-[18px] md:text-[20px] lg:text-[22px] font-medium">
+      <a class="underline underline-offset-4 text-primary-light dark:text-primary-dark" href="https://www.youtube.com/watch?v=k-GhLNZm8G0" target="_blank" rel="noopener">Watch the film</a>
+    </p>
+
   </div>
 </section>